January 14th 1987

     Vice President Douglas Rumble III called the 1158th meeting of the Society to order at 8:07 PM.  President Richard Fiske, observing a tradition established by his predecessors, missed the first meeting of his term on the flimsy excuse of participating in the Diamond Jubilee meetings of the Hawaiian Volcano Observatory, and associated field trips.

     The following visitors were introduced:  Adel Asem, Kuwait Institute of Scientific Research; Joel Kimrey, Water Resources Division of the USGS, Orlando, Florida; Diane Cameron, University of Maryland; Ann Post, Smithsonian Institution; Steve Spradlins, apparently of no fixed address: Ellen Cambe, Virginia Division of Mineral Resources; and Susan Sherwood, National Park Service.

     Not one to be cowed by a preposterously ponderous podium, Leanne Milton, Chair of the Public Service Committee, announced the National Science Teachers Association Meeting to be held in Washington, March 26-29.  GSW is already heavily involved to the tune of (1) a tour of the USGS National Center in Reston, (2) a booth co-sponsored by GSW  and the Naturalist Center of the National Museum of Natural History, which will distribute a resource guide to the Washington DC area (Leanne needs volunteers for the booth), (3) three field guides being prepared by James O'Conner of UDC, and (4) appropriately enough, all these events are being publicized in the Rock Record, the newsletter of the George Mason University, Department of Geology.

     Leannes's second announcement was that GSW is auctioning off a field trip to Popes Creek, Maryland, being led by Robert Weems.  The auction will be on Radio Station WETA, 90.9 on your FM dial.

     The final public service announcement was that planning is underway for a seminar on Careers in Geology to be held at the Fairfax Public Library.  Please see Leanne Milton if you would like to volunteer.

     The first speaker of the evening, Dennis Krohn, began his talk, entitled "Ammonium in mineral systems - oddity or commodity," by telling us that the first ammonium silicates were described fewer than twenty years ago, and that advances since then have come slowly. 

     Krohn used his studies of some selected ammonium silicates, namely buddingtonite, alunite, and illite, to bring us up to date.  Describing buddingtonite as an ammonium feldspar having no distinguishing features in hand specimen that would divulge the presence of NH4, our speaker allowed as how the good stuff must be seen in infrared - actually, the near-infrared.  In alunite, NH4 can substitute for potassium, but again, the presence of ammonium can't be detected in hand specimen.  You guessed it - infrared tells all.  For example, by plotting reflectance versus wavelength, ammonium is directly related to the hydroxy bonds in potassium alunite.  It turns out that wavelengths of 2.0 and 2.1 indicate the absorption band values for ammonium.

     Well, in what kinds of environments can we expect to find ammonium minerals, keeping in mind the ammoniah products are usually kept directly beneath the kitchen sink?  Hot springs are great places for ammonium silicates; as are sedimentary exhalative features like one at Red Dog, Alaska, which is related to black smokers.  So are some coal shales and other organic-rich sedimentary rocks found in the Atlantic Coastal Plain from the Carolinas to the Gulf of Mexico.  The common denominator for ammonium silicates to materialize in each of these three environments is some source of heat.

     Examples of two of these three environments came next.  Some old hydrothermal hot springs at Ivanhoe, Nevada, were active in the Tertiary and left some goodies behind, like mercury, which was once mined, and disseminated gold, which was not, although lotsa drill holes were punched in the ground in the hope the gold would be economic.  Armed with a radiometer to pick up the 2.0 and 2.1u absorption bands, Krohn was able to construct the first map of ammonium minerals ever made, by using said radiometer to detect NH4 at the surface.  His map showed the ammonium minerals occur at relatively restricted localities, and their occurrence pattern is very patchy, with no halos present.  Krohn interprets his map pattern of patchy distribution, sans halos, to indicate structural control rather than an all-pervasive bake-off event by the hot springs.

     Superimposing the microprobe onto his feldspar samples from Ivanhoe, Krohn teased out some information about the sequence of ammonium silicate mineral formation there.  The feldspars are late stage, whereas alunite is etched, indicating alunite formed early, and was altered later.  So in this Tertiary hot spring deposit with alunite and feldspar both present, we have two different chemistries at two different times.  The alunite also has less ammonium than feldspar, but even though the quantity is small, it's stable over a long interval of geologic time, since even as long ago as the Ordovician.

     Krohn described a second environment involving heat - the Cumnock Formation in the Deep River Basin, North Carolina.  Here, Triassic coals interbedded with fine-grained black shale are surrounded by diabase.  Ammonium in illite is found at different stratigraphic levels up the whole section.  Intrusion of the diabase cooked the pile and served up the ammonium.

     Krohn synthesized his results from the Tertiary hot springs at Ivanhoe and the baked Triassic layer cake from Deep River with a model that features (1) hydrothermal convection, (2) reaction with a source of organic matter, (3) interaction with metals, (4) transport along fractures, and (5) a host rock with potassium sites we can substitute for.

     So in answer to the question, are ammonium minerals an oddity?, the answer is definitely no.  And even though they were found with disseminated gold at Ivanhoe, they're not exactly a commodity, either.  Our speaker concluded with a safe, middle-of-the-road statement that the answer is neither oddity nor commodity, but somewhere in between.  Questions by Howard, Greenwood, Sheldon, Sorensen, and Burt.

     The second paper, "The Cambrian face of Iapetus," was by Robert Neuman, USGS, and Michael Max, U. S. Naval Research Laboratory.  Claiming he had drawn the short straw, Max began by saying the main point of the talk was to illustrate regional approaches in solving geological problems; and that he was really just discussing the Cambrian face of Iapetus in passing. 

     In reviewing some of the approaches traditionally used, such as accretion at the edges of cratons, and global plate tectonics, Max made a pitch for unraveling mobile belts by the study of terranes.  Defining a terrane as a body of rock that is a coherent tectonostratigraphic unit which is bounded by shear belts, he pointed out the advantage of not having to worry about a model in which things are either framed, or suitably ignored.

     The terrane Max has in mind is virtually the entire North Atlantic today, with pieces of it scattered around in Maine, Greenland, Ireland, Scotland, and Norway.  In Late Cambrian time, when all these pieces of real estate were closer together, they were mangled by the Caledonian orogeny.  The rocks themselves were mostly deposited by the Middle Cambrian: the deformation was all over by Arenig time.

     The beginning of this scenario was Neuman's discovery of the Penobscot event in Maine some years ago.  Max claims that Neuman is the discoverer, not the father of this event, thus avoiding some possible Penobscotian paternity repercussions.  Anyway, those rocks were a fur piece from Maine when they were deformed by the Penobscot event.  Sometime later they were left on North America's doorstep. 

     Moving away from Maine to Britain and Ireland, the Grampian Mountains of western Scotland and northwestern Ireland have rocks that were deformed at the same time as the Penobscot event.  The Grampian rocks however, show a higher degree of metamorphism and are more highly deformed.  In the Grampians the early deformation phases are related to a subduction event.

     Moving a bit south to southeastern Ireland where some granites are mapped as a series of pinch-outs, we can see from these that there are some major structural features without having to know the details.  Max says they're wrench faults, and once we get to this level, we can look at major shear boundaries annealed by the granite, which then lock the terranes.  So in Ireland and Britain, there is evidence for structural breaks, terrane accumulation, and steeply dipping magnetic profiles.

     Over in Norway, by contrast, there are flat-lying rocks, thrust faults, and nappes.  The flat-lying rocks are a sequence of alternating ophiolites and marine sediments, which is the important thing to remember, because they can be correlated from nappe to nappe, and can give some idea of the original areal extent.  In Britain and Ireland, however, correlation is hopeless because everything is higgledy-piggledy.

     In a grand summary slide, Max took us from the mid-late Proterozoic, when all these pieces were together, to the lowermost Ordovician, when Iapetus was there instead.  In the beginning, the mid-late Proterozoic, a single unbroken continental crust included Greenland, North America, the northern part of Britain and Ireland, and Baltica.  By the latest Precambrian this shelf was under tension between Laurentia and Baltica, as seen by the Delradian sediments in the Grampian Mountains of Ireland and Scotland.  The Early Cambrian shows further tension as the North Atlantic began to spread by propagation cracks.  Failed arms of an oceanic zone indicate the spreading fizzled out.  A subduction zone somewhere was piling up the ophiolites that wound up jammed onto the southern margin of the Caledonides and Grampians.  This is the stuff of which the Penobscotian and Finmarkian events are made.

     In the late Middle Cambrian subduction is still going on and the ophiolites are winding up in the same general area, mostly concentrated in Ireland and Anglesey.  Lots of micro-continents were forming, such as the Porcupine Seabight.  Continental crust and oceanic crust are disposed in complex re-entrants.  Moving right along to the Late Cambrian, ophiolites are landing in the Grampians proper from both subduction and obduction now.  The Grampians themselves are getting munched, zapping the Delradian metamorphic suite in the process.  A main spreading center parallel to the cratonic edge of North America moved from up north down south - not a bad idea, considering the climate outside tonight.  The Menai Strait between Anglesey and the rest of Wales is a major terrane boundary.

     Finally, in the lowermost Ordovician, Iapetus is established.  A final gasp of the Caledonide orogeny produced a lot of thrusting up in Norway to get the nappes.  So, beginning with a single, unbroken spread of continental crust, Max had given it a maximum tension headache, split it, and spread it.  In the process, Iapetus was born (no claim for paternity here, either) and then completely consumed when two plates came together in the Taconic orogeny, but that's a different story.  Questions by Rankin, Stewart, Cameron, and Haugerud.

     Our third speaker of the evening, Jeffrey Post of the Smithsonian, who is co-author with David Bish, Los Alamos, took us on a foray to the dark side in his talk, entitled "Manganese oxide minerals: some new insights from powder x-ray diffraction."  Describing manganese oxide minerals a having a plus four oxidation state and almost without exception being brownish-black in color and massive in texture, Post admitted their one advantage is that one never has to argue about which specimen is exhibit quality material - they all look alike.  In fact, for years the problem of distinguishing between various manganese oxides in hand specimens have been solved by determining how dirty ones fingers became while fondling the sample.  By using this low-tech test, not-so-dirty fingers designated "psilomelane," while filthy fingers were diagnostic for a manganese oxide bearing the improbable name of - get this - "wad."

     With our attention on manganese nodules from the ocean floor taking on more serious overtones as a source of manganese ore, it is worth our while to note these nodules are 40% manganese oxide.  An understanding of these great, heavy, lumpy minerals just might help us to fathom the origin of the sea-floor nodules.  Unfortunately, a problem with these grungy, massive-textured specimens is that one can't use high tech stuff like x-ray diffraction or single crystal neutron diffraction.  Nor will any specific information be divulged by infrared or electron microscopy.  So what's a crystallographer to do, when faced with all this adversity?

     New technology and CHUTZPAH, that's what!  It turns out that some folks have used a high-resolution TEM in conjunction with a new powder x-ray diffractometer with some credible results.  Post and Bish seized upon this technique, pulverized some todorokite, and subjected it to a high-resolution TEM.  Now, Post considers powdered x-ray diffractometry to be a poor second cousin to using single crystals, but when you're working with grunge, single crystals are a pipe-dream, anyway.  The high-resolution TEM works fine for identifying simple structures, but when it comes to the details of these structures, the TEM, like your everyday manganese nodule, is in over its head.  Sadly it turns out there are no completely resolved reflections in the pattern of the powered x-ray sample of todorokite.

     Now its time for the chutzpah part.  Post hotwired the Dutch Rietveld method. Instead of trying to separate each peak in the powdered x-ray pattern, he chose to deal with the pattern as a whole, and to treat each data point in the pattern as an observation.  Starting out with a model of what he thinks the crystalline structure looks like, Post used as variables both atom position and occupancies, each of which were varied so that they best fit the observed pattern of the powdered x-ray sample.

     Another factor in this game of "Outguess the grunge" is a long-standing controversy about todorokite, over whether it was a layered structure or a tunnel structure.  Enter Shirley Turner with her TEM to show it was a tunnel structure held together by a triple-octahedral chain network, analogous to chains of silica tetrahedra.  Reminding us that with the TEM, simple structural framework is no problem, Post told us the framework contained sodium, calcium, water, and in deference to Dennis Krohn, the first speaker, even some ammonium atoms.  But where were these things sitting in the tunnels?  Let's grab some samples and find out.

     Post used two specimens of todorokite, one from Cuba and the other from South Africa. [Notice the Smithsonian doesn't seem to have much of this manganese stuff from the USA].  Starting off with the South African sample, he made plots consisting of the observed peaks from the powdered x-ray pattern: the calculated peaks from the model, and the differences between the two.  At this point he didn't include material in the tunnels, but rather concentrated on his plot of the triple octahedral chain structure.  The plot thickens.

     Putting in atoms whenever the pattern said things weren't very tidy, Post then calculated the difference between the observed densities and his hypothetical ones.  Fiddling around with different combinations made things look even better.  By using the principle that greater electron density meant the greater the occupancy of atoms, Post focused on the peaks and made maps of the differences between observed and calculated values.  After superimposing the difference maps onto a plot of the framework structure, a tunnel you will recall, Post and Bish were more than pleased with the results.  Not knowing whether what they were seeing was an artifact or real, they tried the same thing on the Cuba sample of todorokite and Eureka!, it worked there, too.  Obviously they had hit on a technique that works.

     So after years of mineralogists messing about with such filthy, grungy rocks, there is light at the end of the tunnel, after all.  Questions by Stewart, Freeborn, French, and Sorensen.

     There being no other business, Vice President Rumble adjourned the meeting at 9:47, and eighty members made for the refreshments.




January 28, 1987

     The 1159th meeting of the society was called to order by Vice President Rumble at 8:10 PM, culminating a week that gave us twenty-plus inches of snow in storms on either side of Super Bowl Sunday.  The WEEK THAT WUZ featured OPM's abominable snow plan of the preceding Thursday, a Metro system that was frozen in its tracks, below-zero temperatures, and seven straight snow days in Fairfax County schools.  Things were so bad that Mayor Barry called in sick from California, but, GSW met on schedule.  With parking at a premium, and the Metro system on its knees, Vice President Rumble wished the minutes to state that only the bravest and truest of the GSW membership was able to get out.  The audience gave itself a round of applause, whereupon Rumble remarked, John Wesley Powell must be beaming proudly, wherever he might be.

     Vice President Rumble then announced the death of Vincent E. McKelvey, Director of the USGS from 1971 through 1978, and all present stood for a moment of silence.

     One visitor, Mark Bagantz of Howard University Medical School, introduced himself, remarking that his switching from graduate school in geology to medicine was a tough choice, but then he had to consider the prospect of survival after acquiring the sheepskin.

     In an informal communication, Ralph Haugerud showed us what can be done with a mass spectrometer in trying to unravel some messy results from potassium-argon dating.  Mentioning a publication that said some K-Ar spectra are uninterpretable, Haugerud pointed out that instead of assuming the sample contains only its original argon composition plus whatever baggage it acquired from decay of its potassium, we should ask whether the argon present might not be the result of mixing between the crystal and some reservoir we don't understand.  Questions by Phelps Freeborn, Michael Max, E-an Zen, and Dave Stewart.

     For the first talk of the evening, Glenn MacPherson took us "Chasing seamounts in the northern California Coast Ranges."  Starting off by telling us there is an easy way and a hard way to look at submarine features, MacPherson reminded the audience of Robin Brett's glamorous pictures taken from the Alvin of the pretty stuff to be seen on the sea floor.  As an aside, our speaker pointed out that Brett's talk tended to downplay such unpleasantries as lost gear and seasickness.  And even though fresh pillow lavas might be thin-skinned, MacPherson doubted they were thin enough for Brett to see through.  Then, taking a firm stand for doing field work with his feet steadfastly planted on solid ground, our speaker ventured that all things considered, walking an outcrop was a better way to do things than scooting through the darkness in the Alvin.

     To prove his point, MacPherson showed us slides of subaerial outcrops and sent rejuvenated chills down our spines with a detailed analysis of a place called Snow Mountain, of all things.  Déjà vu the WEEK THAT WUZ!  Snow Mountain has a pile of rocks 2 km thick that start off at the bottom with clastic sedimentary rocks loaded with radiolarian tests that haven't been able to make up their minds about how old they are.  Diabase dikes intrude the clastics and grade up into pillow lavas.  Brecciation in the lavas increases upward, indicating the volcano was becoming more explosive as it grew.  Above the brecciated pillows some more pesky radiolaria separate the lower series of volcanics from an upper series that look like pahoehoe flows this time, not pillows, but with still more brecciation.  Then for good measure we get some graywacke capped by the West Summit series volcanics, the youngest of which are rhyolites.  MacPherson believes the rhyolites suggest a differentiation trend typical of islands and seamounts, rather than mid-oceanic ridge basalts.  Questions by Daniel Milton, Tom Dutro, Ralph Haugerud, and E-an Zen.

     John D. Unger, USGS, presented "Deep structure of the Northern Appalachians in Maine and Quebec:  results of deep seismic reflection experiments," the second talk of the evening.  Alleging that tonight's talk was not a complete summary of what his group has been doing, Unger then unabashedly flashed a slide that revealed a complete seismic reflection study across the northern Appalachians from SE Quebec to the edge of Georges Bank.  Not only did they run said seismic reflection studies (which were compared to the spanking-new geologic map of Maine), they also did a refraction study in conjunction with their reflection lines.  By throwing in a wide-angle reflectors, as well, they could construct a 3-D model of the crust.  Gravity studies helped to round things out.

     These guys focused a lot of their attention on the Merrimack synclinorium, not to be confused with the golden double anticlines of a Big Mac emporium.  They found the crust thinned significantly from northwestern Maine down to the coast:  from a thickness of 40 km down to 10, and that the Moho was a remarkably planar feature.  The Moho in Maine stays mainly in a plane!  A thrust fault, the Norumbega, forms the contact between the rocks of the Merrimack synclinorium and those of an older coastal antiform.  The Cushing and Cape Elizabeth formations of the antiform are overlain by the thrust sheet, and the fault contact was traced to a depth of 10-12 km, where it marked the bottom of the synclinorium.

     In central Maine, gravity studies revealed a steep gradient in the murky depths below.  Luckily, two Devonian plutons were in the vicinity, and they could be conveniently connected at depth like Siamese twins to produce a model which fit the data.  Further east, a high-density feature at depth was not as easy to pin down.  The anomaly was near the Moho, but with a density that was too great for the Moho to account for its magnitude.  Nor was there any outcrop of mafic intrusions to come the rescue this time.  Lacking any tangible evidence for this high-density feature, Unger suggested it may be a down-east aggregation of Mesozoic intrusives at depth.  A-Yup!  Questions by Bill Burton, Dave Stewart, a co-author, no less (twice), Norm Hatch, Gene Robertson, and Bill Greenwood.

     Brooks Hanson, Smithsonian Institution, finished up the evening with his talk, "Mechanics of low pressure metamorphism:  Numerical models and evidence from the Cordillera."  Starting off with the question, "Does magmatism cause low pressure metamorphism?," Hanson gave us at least forty minutes worth of information in half that time.  He answered his own question by observing that rocks can get metamorphosed in the upper part of the crust, a place where temperatures ordinarily are lower, by one of two ways.  Either a single massive intrusion can elevate the temperature in country rocks just that one time over a wide area, or many smaller intrusions can succeed one another over the same area until they appear to be juxtaposed into one bloody big batholith.  Sort of like the difference between a shotgun blast and the life history of a pincushion, taken one poke at a time.

     Getting us into a receptive mood by showing a spectacular slide of the Sierra Nevada batholith, Hanson explained that we were looking from White Mountain Peak to Mount Whitney, 100 km away.  Although most of these rocks have experienced low pressure metamorphism, we were told that the slide covered three different magmatic arcs over time, and the full width of the metamorphic field spans about 180 MY.

     Does mother nature fit the numerical models?  I'll bet not, if she doesn't understand cylindrical coordinates!  If the computer fills up the crust with enough granites, Hanson says the wall rocks never forget, and will integrate all these higher temperatures over time.  The numerical models show the pressure-temperature pattern in the country rock is defined by the array of intrusions, a result which must have been reassuring to the programmer.  Our speaker concluded that regional low pressure metamorphic mineral assemblages will form at pluton densities of greater than 50%, the point beyond which lots of little intrusions over time really can look like one humongous batholith.

     Two questions by Ralph Haugerud revealed that he, for one, did understand cylindrical coordinates.  He got our speaker to admit you can't generalize from models of a single pluton to a multiple model by using cylindrical coordinates, but you could in a cartesian model.  As Haugerud and Hanson both have Scandinavian surnames, the question was really one of Descartes before the Norse.

     With an invitation to the 41 brave and true members to return on February 11, Vice President Rumble adjourned the meeting at 10:01 PM.




February 11, 1987

     The 1160th meeting of the society was called to order by President Fiske at 8:02 PM, and in the remarkably short span of two minutes, most of the assembled visitors, guests, and members, including those in good standing and those in arrears, had taken their seats and had achieved a semblance of decorum.  The minutes of the previous meeting were approved as read.  Six visitors were present, three of whom unabashedly introduced themselves.  Mike Phillips of Florida said he was here looking for a job (there seem to be a lot of that going around lately).  Anders Asland and Marcus Key both are at the National Museum of Natural History.  The three others who were introduced are Yang Chi Qing, The George Washington University, Lisa Helton, Howard University, and Christian Repetski, who was celebrating his first birthday by having his diaper changed elsewhere in the Cosmos Club.  Only one year old, and already this kid is in arrears.

     The names of six newly elected members were announced:  Alan Driscoll, Jr., Patricia Watterson, Barbara Eisworth, Steven Shirey, Susan Sherwood, and Christopher Beza.

     On behalf of the Public Service Committee, President Fiske announced that the schedule for upcoming science fairs was now available for those who were to be judges, and that GSW will present Walter Sullivan's book, Land Prints, to the various science fair winners.  John Repetski asked about the fate of a GSW member who had been auctioned off on radio station WETA.  Leanne Milton replied that WETA got the money GSW got the publicity, and that Rob Weems, the auctionee, will get to lead a field trip in the spring.

     Daniel Appleman gave the first of two informal communications dealing with fire and ice by reading us a hot flash from Antarctica where the Joides ship, Resolution, is basking in the austral summer.  Breathlessly reading us communiques radioed from the ship, straight from the poop deck as it were, Appleman reported on drilling at two sites near the Maud Rise.  The first drilling site penetrated to within 30 meters of the basement and yielded sediment cores loaded with microfossils.  These sediments show a remarkable lack of reworking, and the KT boundary comes complete with volcanic ash, which, together with the microfossils, provide plenty of ingredients to play the dating game.  Fortunately, the KT boundary coincides with those elsewhere, and even as Appleman spoke the microfossils were busy providing the southernmost anchor of Cenozoic biostratigraphy.  Site two bored deeper than site one, through 320 meters of sediment, into the basement this time, which was a basalt loaded with vesicles and amygdules.  On the way down the KT boundary was encountered once again, still marked by volcanic ash, and still coinciding with those found elsewhere.  The only questioner, Dan Milton, wanted to know who was determining that ash, anyway, some paleontologist?  Matches, matches, M-A-T-C-H-E-S.  Matches, matches, M-A-T-C-H-E-S.  You can strike 'em on paper, strike 'em on glass - I once knew a man who could strike 'em on his ASH-can; Matches, matches, M-A-T-C-H-E-S.

     The second informal communication, dealing strictly with fire this time, was given by Bob Tilling, who, along with our wayward president, was just back from some hi-jinks in Hawaii.  Under the guise of participating in the Diamond Jubilee seminars of the Hawaiian Volcano Observatory, throughout the month of January, and, with the dedication of a new building thrown in for good measure, Fiske and Tilling almost had us fooled until the first slide.  These two really let it all hang out doing a hookey lau in concert with Dallas Peck, Tom Wright, and William P. Mott, the head of the National Park Service, all aided by an even more motley assortment of native dancers.  In an effort to put an honest face on this boondoggle, Tilling showed a magnificent slide of a sky-high lava fountain that dwarfed a helicopter in flight.  WAIT!  Was this venerable band of dancers really being choreographed by Ponce de Leon?  The continuing eruption of Kilauea, which began in 1983, added 250 meters of material above the 1983 surface before the high fountains changed to lava lake activity last July.  Small degassing fountains around the edge of the lake still managed to provide plenty of challenge to the intrepid geologists gingerly doing their sampling among the fountains, provoking feats of agility some probably weren't aware they had!  Perhaps Ponce de Leon didn't desert this clambake after all!

     Lava tubes allowed lava to reach the sea around Thanksgiving for the first time since 1973.  Owners of the 29 houses consumed en route are probably not as thrilled as geologists are by the fact that the lava added 18 acres of new land to the sea in about two week's time.  There goes the neighborhood!  Questions by Ralph Haugerud, who wanted to know how the new shield got shorter as it grew, Dieter Johnson, E-an Zen, and Roz Helz, who offered a comment that the small degassing fountains surrounding the lava lake still serve as chimneys to release the volatiles.  Moto Sato said he had been ready to say what Roz just said, and then he said it again.

     The first formal talk of the evening may have provided a first for GSW, with Jack Epstein billed as speaker, with one asterisk, and Peter Lyttle as answerer, with two.  Epstein deftly saved himself from a pratfall as he tripped to the podium, and then, with great panache, he leaned on the sympathies of the audience as he pleaded laryngitis.  Rasping an appeal to help him conserve his flagging vocal cords, he asked the audience to say AAH, on cue, followed by a languorous OOH.  While the speaker was busy trying to further mesmerize the audience, the two-asterisked answerer remained silently glued to his seat.

     Finally getting to the heart of it, Epstein said he was really going to talk about the chronology of deformation in the north-central Appalachians, and its significance, or, the mystery of the Taconic hiatus deposit.

     For those who just came in, the base of the nitty-gritty Shawangunk Conglomerate of Middle Silurian age unconformably overlies the more shaley Martinsburg Formation, a thick pile of marine rocks which are Upper Ordovician.  The Taconic angular unconformity between the two spans about 30 MY and stretches 128 miles from the Taconic allochthon in New York to the Hamburg Klippe in Pennsylvania.  Ever since H. D. Rodgers identified the Taconic angular unconformity in 1838, geologists have been debating about just exactly what happened to which of these rocks where, and when.  After having poked in the nooks and crannies of this unconformity, our speaker said not to worry.  Summarizing the features at four nooks and three crannies, he told us the Martinsburg rocks beneath the Taconic angular unconformity (1) are beveled at an angle that varies from 2-15 degrees, (2) experienced their dominant folding during the Alleghenian orogeny, and (3) have Taconic cleavage with an Alleghenian overprint.  Also, the Taconic folds are broad and open, and the Taconic trends are more northerly than those of the Alleghenian.

     The best part was yet to come.  Epstein wanted to know what else went on during the 30 MY hiatus while the Taconic angular unconformity was being eroded, and went in pursuit of the Taconic hiatal deposits.  For one thing he found diamictite that apparently was the product of mass wasting.  At Mount Menago, New York, there is a shale chip gravel deposited on the Martinsburg surface, reminiscent of a Pleistocene chip gravel, together with some colluvium consisting of silt and clay.  Convolutions in the bedding, together with slump features suggest frost heaving, and fortunately a glacial center was not too far away in the Ordovician.  Some cobbles of laminated quartzite in the hiatal zone have weathering rinds, indicating exposure to air.  And finally, slickensides in the Martinsburg are associated with another diamictite, which our speaker says is fault gouge.

     So, from whence have these rocks in the hiatal zone come?  From the Passaic Formation of speculative age to the northwest, that's where.  When the marine Martinsburg was uplifted during the Taconic orogeny, the Passaic Formation was weathered and then produced clasts from a source that is now nowhere nearby.  Said clasts piled up to become the hiatal deposits anytime from, say equivalent to the lower Martinsburg, to perhaps the Upper Ordovician.  All this was sounding pretty good until Epstein told us the source area had long since been eroded, along the Taconic thrust sheets.

     So here we have a 30 MY hiatus, separating rocks that were ruptured by Alleghenian cleavage.  With a hiatal hernia of that magnitude, I say forget about Epstein and Lyttle, it's in God we TRUSS!  Questions by Anita Harris John Repetski, and E-an Zen, who wanted to know if an official answerer was the same as an official spokesman.  The official answer from Peter Lyttle was an emphatic, NO!

     The second scheduled talk was not given because the speaker, Michael Cline, had been called out of the country.

     Stephen Phipps finished up the evening with his talk, "Style and tectonics of re-activated basement structures, U. S. mid-continent."  Telling us that he would stick to the facts, then generalize, and not enumerate, Phipps projected a map of the southeastern United States showing more than 25 numbered structures, and proceeded to enumerate their virtues.

     Phipps launched into the four types of structural styles he recognized.  Leading the pack was the Wichita frontal fault system of Oklahoma.  Here, the basement faults were thrust over the Anadarko basin for all to see.  The Tishomingo Block in the south Oklahoma allochthon contains a deep sedimentary basin with what Phipps calls propeller faults - certainly a unique approach to moving rocks from one place to another.

     But, keeping abreast of technology, Phipps abandoned propellers for a jet to show us a view from six miles above the Arbuckles.  From this vantage point we could see a steeply dipping forelimb, a flat top, a gently dipping backlimb flattening out to zero dip, and finally the whole thing runs into another structure.  The fault upon which the Arbuckles are riding flattens out at depth, a feature Phipps calls sled runners.  Jingle bells, jingle bells, jingle all the way.  Oh what fun it is to ride a thrust fault every day.

     The second kind of structure is a basement-cored asymmetrical anticline as seen in the Nemaha Ridge of Kansas.  With structural relief of less than one km and Emporia stuck smack in the middle, it's no wonder Horace Greeley told the young folks to head west.

     The third kind of structure is a basement fault overlain by a whole series of en-echelon faults, which could be formed under the influence of lateral shear.  Forsaking propellers, jets, and sled runners, our speaker said a small right lateral fault with motion of one km is enough to do the trick.  Turning the screw in his own way, it was about here that Doug Rankin registered his first officially recorded snore of the 1987 season.

     The fourth and final kind of structure is produced by re-activated normal faults such as seen in the carbonates of Natural Bridge State Park, Kentucky, where Pennsylvanian limestones are against Mississippian clastics.

     Phipps now asked the rhetorical question, are there structures like this in other orogens of the world?  Of course the answer was yes, with examples of re-activated thrust faults in the Alps and Paris Basin, and a re-activated normal fault on the Isle of Wight.

     But the Alleghenian orogeny provided Phipps' pièce de résistance.  He assumed the Appalachians were rigid blocks moving independently of one another.  The deformation we see is at the boundaries of these crustal blocks, and Phipps coined the term, "crustal mesoplate tectonics," to describe what had gone on.  He blamed it all on failed rifts, with an original collisional orogen somewhere off to the side.  Dêcollement could be explained by detachment of the rigid upper crust from weaker stuff below, and failed rifts could provide magnificent avenues for magmas.  But, Phipps was no Phineas Phogg, for even though he used propellers, jets, and sled runners, he finished four minutes over the 20-minute mark.  Questions by George Helz, Bill Berg, Ben Burton, and Sorena Sorensen.

     President Fiske requested that the 25% of the membership in arrears please pay their dues, and announced the program for the next meeting.  The meeting was adjourned at 9:38 PM, and attendance was 74 members, ALL in good standing - of course.




February 25, 1987

     The 1161st meeting of the society was called to order by President Fiske at exactly 8:00 PM, catching everyone by surprise.  Rising to the challenge, the audience was fully seated by 8:01, beating last meeting's time by a full minute.  The minutes of the previous meeting were read, and read, and read.  Although neither approved nor disapproved, they were blissfully terminated.  Six visitors and guests were present:  James Hertzler, Will Lamb, Jonathan Freese, Kevin Howard, Sam Adams, and Ann Brewster.

     Leanne Milton, chairperson of the Public Service Committee, announced the need for 15 volunteers for science fairs between March 14 and April 4.  And for the National Science Teachers Association Meeting to be held in Washington March 26-29, one volunteer is needed to help man the booth being co-sponsored by GSW and the Naturalist Center of the National Museum of Natural History.

     In an informal communication, E-an Zen alerted the membership to the potential for their being listed as a co-author without their knowledge.  Citing the January 15 issue of Nature, in which Stewart and Feder dissect the scientific papers of one John Darsee, a confessed forger of data, Zen went on to say that Stewart and Feder questioned to what degree Darsee's 47 various and sundry co-authors shared in his fraud.  For example, in the biological sciences, honorary co-authorship is common for those associated with the laboratory whose facilities were involved in the research.  Zen suggested that co-authorship without contribution could lead to distortion.  Further, Stewart and Feder's claim that the threat of a libel suit against them for an earlier, unpublished version of their Nature article actually constitutes a form of censorship.  Zen said he was placing the situation before the group to see if this was a problem in the earth sciences.  Comments by Phelps Freeborn, Kathleen Krafft, Rosalind Helz, Daniel Milton, and Richard Fiske.

     For the first talk of the evening, Fred Doyle exposed us to the "Large-format camera on the space shuttle."  Large format in this case is no exaggeration, each frame measures 23 ´ 46 cm, twice the size of an aerial photograph.  No instamatic, this outfit, complete with stellar cameras and a terrain camera, needed no less that the space shuttle to haul it around.  Large format and LARGE COST, Doyle says.  Nestled in the cargo bay of the shuttle and using slow-speed, fine-grained film, the terrain camera takes pictures with 80% overlap, providing superb stereo coverage.  The exquisite resolution we were yet to behold.

     Doyle took us on a magnificent tour through the eyes of this system to let us see its capabilities firsthand.  We went from Montreal to Cape Cod, where we were treated to a view that measured l degree of latitude by 2 degrees of longitude.  Remarkable as that was, Doyle showed us we could easily get twelve adjacent enlargements from a single frame, each enlargement at a scale of 1:250,000!  From the overall view of Boston and Cape Cod, one of these enlargements zoomed us in on a time-lapse series of a passenger jet landing at Logan airport, captured with ease from successive frames.  Then on to the Tibetan Plateau, Mount Everest, Katmandu, and Italy, where an enlargement showed us Venice, its bay, canals, beaches, and ships; and our speaker swore he could see a girl in a red bikini!

     Quick to dispel any notion that our photographers were voyeurs in space, Doyle now revealed some of the camera's more sobering scientific applications.  For example, Beijing has used an enlargement of Mount Everest, complete with glaciers, to construct a contour map with 50-foot intervals.  By setting up ground control points ahead of time, as was done in the Black Hills test area by our own boys, the large-format black and white prints can be combined with LANDSAT imagery to aid in resolving 1:24,000 maps.  In fact, from an altitude of 225 km, which gives coverage of 170 X 340 km per frame, resolution from the large-format camera knocks the socks off LANDSAT's multispectral scanner.  Planning was underway to get more of these amazing pictures from a polar orbit when the space shuttle accident occurred last year.  So for now, it's "Goodnight, sweet prints."  Comments and questions by Jim Garvin, Keith McLaughlin, Gene Robertson (twice), E-an Zen, Phelps Freeborn, and Alta Walker. 

     Curt Larsen presented "Isostatic uplift in the Great Lakes," the second talk of the evening.  Larsen reminded us that although isostasy is an everyday word today, in the 19th century it was a highly controversial concept.  G. K. Gilbert was one of the first to use isostatic adjustment in his explanation of the terraces of Lake Bonneville.  At the same time, Thomas Crowder Chamberlain, a rigid-earther, was totally opposed to the idea.  So guess who published the first Quaternary study of the Great Lakes region?

     Noting that a lot of today's Lake Michigan basin once contained glacial Lake Chicago, a late Wisconsinan feature, our speaker told us that as we head north, the depressed crust got deeper and deeper.  James Goldthwait came out from Harvard early this century to see for himself.  He traced the terraces from the south end of the lake, down where it drained toward Chicago, up north.  When Goldthwait got to Greenbay, Wisconsin, the terraces diverged; so he postulated a hingeline to account for it.  South of the hingeline, nothing had moved; north of it, there was dramatic movement, indicating lots of rebound.  Gilbert, always willing to help, had suggested that if one used lake-level gauge records, one could determine uplift rates.  Naturally he was ignored by geologists, but heeded by engineers.

     Larsen says although Goldthwait's model acknowledged the drainage southward toward Chicago, he missed the outlet to the north.  But to be fair, Goldthwait didn't have lake-bottom cores in which the horizon of red clays is a marker for the last of the pre-glacial pre-glacial lake surfaces.  Our speaker told us glacial lake Algonquin came after Lake Chicago and was many times larger, so that it straddled the North Bay sill, and covered part of Canada.  Canadian data show that the place where former Lake Algonquin stood is higher up north today than it is on the south side of the sill in Michigan.  With rebound, Larsen says, the North Bay sill eventually blocked drainage to the north, and all the rivers were then pushed back to drain to the south into Michigan.  Moral:  the best way to recover from a period of depression is to go with the flow.  A question by Bob Tilling and a comment by Karen Prestagaard.

     Ursula Marvin finished up the evening with her talk, "The meteorite Ensisheim:  1492-1992 (almost)."  This delightful account began with the horrendous explosion heard in the Rhineland on November 7, 1492, when the meteorite landed at Ensisheim.  A true sonic boom, the explosion was heard within a radius of 95 to 120 miles, depending upon whom one talked to.  It was heard in the Alps, along the Danube, and it caused the French to tremble.  Showing no such trepidation, souvenir hunters immediately started chipping away pieces until the chief magistrate put a stop to it.  Publicity and propaganda have kept the Ensisheim meteorite before us ever since.  Fortunately, it fell about 35 years after the invention of printing, so the occasion provided the prototype for media coverage of a geologic event.  Brandt put out broadsheets complete with a woodcut of the stone coming out the  sky, and simultaneously resting on the ground.  It had a German text paralleled by one in Latin; cited the authorities (in this case Pliny, who lived 1400 years earlier), described the event, and concluded: "I don't know what it is!"

     As for the propaganda, the advisors to Maximillian I, Emperor-elect of the Holy Roman Empire, told Max the meteorite meant good things for him.  Maximillian was spoiling for a fight with Charles VIII of France.  In the following January, Max had his war and won.  He also agreed with the magistrate that the meteorite should be protected from further vandalism, but only after he took a few pieces for himself.

     As time went on, the meteorite acquired more and more status, in spite of the first chemical analysis in 1800, which declared it to be a common, ordinary stone.  In search  of a suitable repository, the people of Ensisheim placed it in a church in 1804, which suited everybody just fine until the church fell down.  Now it is properly on exhibit at the Hôtel de Ville, protected by two officially appointed Guardians of the Meteorite, each decked out in a flaming scarlet tunic and brandishing a medieval axe.  But the most substantial way the Ensisheim meteorite is commemorated is with a local brew, Meteor Bier.  Questions by Moto Sato, Gene Robertson, and Dick Fiske, who wanted to know why 1992 in the title?  Marvin replied that she still wasn't done with this, and besides, so far she's had three trips to Ensisheim, at which point there was a collective gasp from the audience.  Perhaps feeling the need to explain, Marvin said that way up into the 1770's they were still talking about this meteorite.  One thing for sure, this lady really knows how to go for baroque.

     President Fiske announced the program for the next meeting to the 91 in attendance, and adjourned us at 9:54 PM.




March 11, 1987

     You will recall that four weeks ago tonight, the 1161st meeting of the Society was called to order by President Fiske at precisely 8:00 PM, catching everyone by surprise.  However, the audience rose to the challenge, and was fully seated and ready for business at 8:01.  In stock-car racing jargon this nimble bunch had an elapsed time of just one minute from beer keg to business agenda.  At the last meeting, the 1162nd, our president overcompensated and called the meeting to order at 7:59 and 30 seconds, really bending the cool of some of our more seasoned socializers.  Amid much grumbling, griping, and last-minute groping for enough liquid sustenance to carry themselves through the opening moments of the meeting, our group again settled down at 8:01, a remarkably consistent performance.  Let this be a lesson to our leader, that to prematurely withdraw warm and cuddly geologists from their source of suds, can reduce these guys to a bawdy rabble.  It's OK folks, the spell is broken.

     The minutes of the previous meeting were read and corrected.  Four visitors were present and duly applauded:  Ishio Moriya, Japan: Mike Koska, University of Michigan: John Perso, __??__; and Robert Lowell, NSE.  I still don't know what that (NSE) stands for.  The names of two newly elected members were read:  Kevin Howard, USGS; and David Hawkins, The George Washington University.  There being no announcements - not even one more plea for science fair judges - we proceeded directly to the regular program.  The evening's fare sandwiched an innocent oceanographer between two theoretical petrologists, each armed with a PC.  Armed, and loaded, as it turns out.

     For the first talk of the evening, Ralph Haugerud spoke on "Cooling history of the Nason block, Baja, British Columbia."  Haugerud explained the title by telling us that his area is not in British Columbia at all, but south of there, like Baja is south of California.  The paleopoles in this mountain wilderness are displaced and discordant.  To explain why, our speaker offered two possibilities.  Either these paleopoles were tilted in place, rotating as they were tipped, or, the entire region has moved northward since the Cretaceous, in which case they could have come from as away far as Baja, California, along a transform fault.

     To decide which was which, Haugerud chose the Nason block because it was a good place to do PT work on aluminous rocks.  Ages on hornblendes are concordant locally, but in running 40 miles across the block, muscovites are younger along a line to the east.  Various plutons pierce the quiet solitude of this place, perhaps upsetting and resetting some clocks in the rocks.  Varying degrees of metamorphism tend to cloud the regional history even more, but in an elegant synthesis direct from his PC, Haugerud showed us what he thinks happened.  An analysis of 21 argon dates indicates the younger ages to the east are produced by release of strain, not by reheating.  If the igneous hornblendes date an initial rapid crystallization of the pluton, then the lower temperature micas could be recording a later cooling event, which was slower.  The younger K-Ar dates to the east can then be explained by an unroofing event in the Cretaceous, followed by tilting up to the NE in the Eocene.  The alternative is to assume the discordant mica dates are from atmospheric argon contaminating the sample, which isn't half as much fun.  Haugerud says that tilting the Nason block isn't enough to give us the discordance we see, so there must have been some transport, too, even if it wasn't from as far as Baja.  I still think that stripping off the overlying rocks is an a-peeling solution.  Questions by two others who have PCs; Brooks Hanson and E-an Zen.

     Ellen Kapell, the innocent oceanographer, presented "Volcanic episodicity and a non-steady-state rift valley along the NE Pacific spreading centers:  Evidence from the Sea-MARC I, Seabeam, and deep-sea photography.  You remember, Ellen, she's the spunky lady who tried to set Robin Brett straight on the details of an Alvin dive during his presidential address.  Ellen should know - she's mapped the equivalent of five quadrangles down there with the help of fancy gear like Seabeam and Sea-MARC.  The Seabeam system attaches to the hull up front to give swath-map bathymetry with its 16 eyes.  Sea-MARC gives bathymetry too, from deep sonar towed behind the ship.  Now how can you beat a system that not only tells you where you're going, but where you've been?  With a sled from Lamont, complete with underwater Limpus camera, and a Panasonic video, that's how.  Even though they started out just to make the bathymetry better, and did (by producing a contour map with a 5-meter interval), Ellen says it's the photos that tell us all about the really good stuff luring in the murky depths below.

     In the Juan de Fuca ridge system, she believes there is evidence for a non-steady state condition at the site of the rift valley, AKA the elongate summit depression, or ESD.  For example, Ellen showed us fresh flows on the flanks of the ridge crest.  Some of these flows wound up on the floor of the rift valley, or ESD, where they show more fracturing and faulting than their outboard complements on the flanks.  And we saw a volcano that is shaped like an archer's bow in plan view instead of line an upside-down ice-cream cone as it should be.  These things, she says, are evidence for collapse followed by extension, rather than for steady state.  Whatever is going on down there, I don't see how this place can look so rugged, and yet be so peaked.  Questions by George Helz, Moto Sato, and Joe Boyd.

     While introducing the final speaker, E-an Zen, President Fiske reported that E-an earned his BA degree from Cornell - he thought sometime in the Silurian.  Zen, the second wild and crazy speaker on the program with a PC, followed up on Ralph Haugerud's model and talked about "One-dimensional models for progressive partial diffusion."  I'm not sure how he got from no rocks at all, to stacks of thrust sheets producing incubation and warm-up at depth, then through a slew of graphs, to get plutons that look like polliwogs, both in Nepal and Massachusetts.  Zen says the bulgy part of these tadpole-shaped plutons is what was intruded as a result of partial fusion, and the tail is what was left behind.  He did!  A sure case of the tail wagging the wog.  Heavy grilling by a shirt with brown stripes and Gene Robertson.

     President Fiske announced the program for the next meeting to the 67 in attendance, and adjourned us at 9:35 PM.



1163rd MEETING

March 25, 1987

     The 1163rd meeting of the Society was called to order by President Fiske at 8:02 PM, and the audience was ready for action at 8:03.  The minutes of the previous meeting were read and corrected.  Eight visitors were present:  George Blufort, a tan sport coat who mumbled, Vince LaPiana, Peter Eisington, Rong Jai-yu, Shi Xiao-yin, Jonathan Freese (who has been here before but hasn't joined yet), and Emma Booy.  The Spring field trip to Calvert Cliffs was announced for May 9, and President Fiske put in a plug for all dilatory and delinquent members to PLEASE pay their dues.  You know who you are.

     Bruce Wardlaw, wearing a woolen cap from Swat, gave the first of three informal communications on his recent field work in Pakistan.  Bruce, always a high-stepper, had to really lift his feet to get at the Permian fossils this time.  The Pakistani officials in charge saw Wardlaw coming, and in honor of his visit they released a torrent of water into a stream which lay between the end of the road, an his outcrop.  But it was worth it all for the open-air cooking in a six-foot wide fry pan, and besides, the Smithsonian was paying.  In the second informal communication, Bob Neuman told us about some brachiopods the Chinese have newly reported from (1) Mount Everest, (2) north China, and (3) south China, that closely resemble an assemblage of Ordovician brachs from Newfoundland.  "Have rofophore, will travel."  Phyllis Renzetti concluded the informal communications with a tour into conjecture land vis-à-vis the geologic time scale.  Having duly noted there is a periodicity of events in the Phanerozoic; you know, things like transgressions, regressions, and extinctions, Renzetti decided to talk about what she termed "circular time."  She says it looks as if the world still goes 'round and 'round in an elliptical orbit, just as it usta, while all the time the earth and sun jiggle up and down out of phase with one another like horses on a merry-go-round.  No wonder us passengers on spaceship earth get dizzy while we're being spun dry, ying-yanged, and yo-yoed.

     For the first formal talk of the evening, Trent Haselton asked the question, "Does the presence of fluorine significantly affect mass transport in high-temperature hydrothermal solutions?"  Noting that the presence of fluoride in low-temperature aqueous solutions, ie., municipal water supplies, significantly reduces the probably of tooth decay, Haselton suggested the cavities and fractures in wall rocks surrounding a silica-rich magma in its waning days might also benefit from the presence of fluids containing fluorine.  But of course.  Fluoride lowers the viscosity of melts, as well as aiding in the transport of major cations in the fluid phase.  Not only that, but silica solubilities are enhanced a whole lot by the presence of fluorine, and apparently fluorine complexing has a great deal to do with potassium activity and the concentration of aluminum.  In fact, Haselton says straight alkali complexing is not very important at all because the complexing of silicon and aluminum takes care of practically all of the fluorine.  So if you're a cavity in wall rock and the fluoride's all gone, there's nothing else to do but say, "Fangs for the memory."  Question by Sorensen.

     Michael Cline presented "Methods and problems associated with assessing earthquake hazards in Central America,"  the second talk of the evening.  Unfortunately for Central America, it lies upon the Caribbean plate on the lee side of a subduction zone, and it catches a lot of grief as the Cocos plate bumps and grinds down into the Central American trench.  Recent earthquakes in El Salvador, Guatemala, and Nicaragua have been grisly affairs, producing death tolls of 2,000, 30,000, and 18,000, respectively.  The song says Managua, Nicaragua, is a wonderful place, but the 1972 earthquake was particularly devastating as it occurred at Christmastime, destroying 60% of the structures and damaging another 30%, leaving only 10% intact.  The city burned for five days and the government was inoperative for a lot longer.  By 1975, Managua was finally cleared of debris and a major decision was made for the government to remain there.  Rampant development around the perimeter of the cleared area indicated a real need to organize before all the dangerous places were covered with buildings again.  Enter Roy Weston, Inc., and our speaker, wearing white hats.  They looked at the historical seismicity, air photos, side-looking radar, low-sun-angle photos, and checked it all out from the air.  On the ground they constructed trenches across the fault zones, and established trench logs, some of which could be dated.  From all this they were able to map 17 active faults in Managua, and to establish the slip rate on quite a few.  The good news is that Cline and company are now embarking on similar investigations in Costa Rica and San Salvador.  Questions by a brown jacket, Bill Howbrick, Gene Robertson, E-an Zen, and Debbie Juarez.

     Donald LaMar, of Zip-A-Dip Protractor Co., and USC, finished up the evening with his talk, "Tracking J. Tuzo Wilson's elusive North American transform."  But not before LaMar gave a silent commercial for Zip-A-Dip by showing us his blazer was reversible by wearing it inside out, revealing all kinds of nifty slogans for Zip-A-Dip, and lots of pockets to hold his wares.  Soft sell, to be sure.  But back to J. Tuzo Wilson, who thought the Great Glen fault of Scotland connected with the Cabot fault of North America.  Later, Harland wanted to include the Billefjorden fault zone of Spitzbergen, Norway, as well, making this one whopping big transform.  Eventually, the Cabot was no longer considered to be a transform fault.  Harland said the Billefjorden "transform" had moved 1000 km sometime after the Devonian, but before the Carboniferous, and was left lateral.  LaMar had his doubts, and besides, Norway has such spectacular scenery, why not find out for himself?  Operating between a field hut the size of a piano box, and a combination beer hall and restaurant for which a sign was not necessary, LaMar and his Zip-A-Dip cohorts mapped relentlessly.  Dodging glaciers, visiting Russians, and an apparently endless supply of Zip-A-Dip field equipment strewn about, they determined Harland's transform was actually a reverse fault with the Heckla Hoek Gneiss riding up over the Devonian Old Red Sandstone, all unconformably overlain by the Carboniferous.  So the whopping big transform came unzipped, dropping the Billefjorden fault along with the Cabot, leaving only the Great Glen fault as the sole surviving transform.  So in the words of yet another great commercial enterprise, "Why Zip, Zip, Zip, when one Zip'll do ya?"  Questions by Gene Robertson, E-an Zen, a blue shirt, and LaMar, himself, who wondered why nobody had asked about paleomagnetism, and then told us all about it.

     President Fiske announced the program for the next meeting to the 73 in attendance, and adjourned us at 9:56 PM.




April 8, 1987

     The 1164th meeting of the Society was called to order by President Fiske at 8:02 PM, and true to form, the gallery of geologists and other assorted gurus weaned itself from the beer table with surprising alacrity, and was seated in one minute flat.  The minutes of the previous meeting were read and corrected.  Four visitors were present and duly applauded:  Charlie Prewitt, Director of the Geophysical Laboratory; Johann Gieb, University of Marburg; and a set of bilateral Gregs from Johns Hopkins, one Dipple and a Sims.  President Fiske announced the council's progress in resolving the chronic condition of late, errant, and otherwise missing meeting notices that are seemingly sucked into another dimension.

     On the fun side, James Clarke invited us on a field trip to Calvert Cliffs to be held Saturday, May 9, promising something for everyone - you know, things like heavy minerals, migration of fluids, weathering phenomena, shoreline processes - the usual fare of GSW's program agenda.  Tom Dutro protested vigorously that fossils are the REAL reason people to Calvert Cliffs, which seemed to catch Mr. Clarke by surprise.  Apparently paleontologists are more of an endangered species than we thought!

     In an informal communication, Daniel Milton told us about some strange goings on in the plagioclase feldspars from a dismembered mélange in the Appalachians.  Dan saw a calcic plagioclase rimmed with a more sodic one, along with some discrete crystals of sodic feldspar.  Examination by SEM confirmed all this, leading Milton to believe there were at least two, maybe three plagioclases present.  Dan said he didn't know what led to the wild and crazy array of plagioclases, or, for that matter, if the rocks were the result of prograde or retrograde metamorphism.  If anyone can give any evidence these are NOT phases in equilibrium, he'd like to hear from you.  Operators are manning the switchboards now - that's 1-800-GEO-HELP.

     For the first formal talk of the evening, Dan Hayba presented "Fluid inclusion evidence for hydrologic and hydrothermal processes in the Creede mineralizing system, Colorado."  With over 2500 observations under his belt, Hayba was loaded to the hilt with data.  If you really want to concentrate a sodium solution, he says, BOIL the stuff until it steams.  That usually happens at depth, perhaps lending a new dimension to the term, briny deep.  If the roof leaks and snowmelt at 0ºC drips through, one can always be thankful for the increased possibility of shallow mixing.  Pressing the fluid inclusion data for all 2500 observations into service, Hayba produced an elegant model for the paleohydrology of the Creede District.  By tweaking ore bodies with such romantic names as the Bulldog Vein, Southern Amethyst Vein, OH Vein, Midwest Vein, and Northern Amethyst Vein, Hayba determined the Creede system was fed by two different sources, one from the north and the other from the south, with deep mixing between the two.  Now it's difficult to see now he could get such magnificent results, when all his observations were in vein.  Questions by Bob Tilling, Dave Stewart, Phil Bethke, E-an Zen (twice), and Phil Candela.  Paul Barton answered Candela's question before Hayba could do it himself, which prompted our speaker to tell Martin, "I'm glad you came!"

     John Valley presented, "The role of fluids in crustal metamorphism," the second talk of the evening.  If you like fluids in ore veins, you'll love fluids in the deep crust, where rocks can get from amphibolite facies to granulite with the greatest of ease.  The problem is we don't always know just exactly how the rocks did it.  Our speaker reminded us that the traditional ways consider the activity of water with respect to pressure and temperature.  We should also remember that fluids can mean flooding, and there are those who like the idea of swamping the deep crust with either methane or CO2, as well. Trying to decide which of these scenarios has happened is tricky to decipher, because the fluid inclusions by themselves are misleading, as Valley says they form after the peak of metamorphism.  In the Adirondacks, for example, he told us that calcite in veins resulted from healed planes of CO2-rich fluid inclusions, and they indicate a brittle, post-metamorphic event.  Clustered near the calcite veins are fluid inclusions which contain mixed water and CO2, and our speaker says all this indicates the inclusions are telling us not about the peak of metamorphism, but rather about the path of uplift.  Furthermore, there is no evidence for a pervasive CO2 flooding event.  Thank goodness!  Having your basement flooded with either water or swamp gas is bad enough, but Lawrence Welk bubbles, too?  Questions by Eileen McLellan, Sorena Sorensen, Paul Lohman, Doug Rumble, Moto Sato, E-an Zen, Dave Stewart, and James Clarke.

     Tom Jordan finished up the evening with his talk, "Are there continents on the core-mantle boundary?"  Noting that the program was taking us deeper and deeper into the earth, Jordan presented a model of how he thinks our planet might be working.  Armed with a whole heap of seismic data, he figured the behavior of seismic waves could be explained by a boundary layer of either a chemical or thermal nature at the core-mantle interface.  This is just what we do with respect to the continents, Jordan says, hence the title of his talk.  Any heterogeneity at the core-mantle interface can be explained by complications either above the boundary, below the boundary, or at the boundary, itself.  As to what this stuff may be, or exactly where it is, nobody knows, but it could be something like either the dregs of a subduction zone, or primary chemical layering left over from the origin of the earth.  In response to a question from Doug Rumble, Jordan replied, "Don't believe anything a seismologist tells you, but you can rely on me!  Now I ask you, would you buy a used seismometer from this guy?  Some heavy grilling by Robin Brett, Sorena Sorensen, Gene Robertson, Dave Stewart, and E-an Zen.

     President Fiske announced the program for the next meeting to the 118 101 in attendance, and adjourned us at 10:0l PM.




April 22, 1987

     The 1165th meeting of the Society was called to order by the President Fiske at 8:00 PM.  The minutes of the previous meeting were read, and corrected, as usual.  Tom Dutro raised a particularly picky point of order about how the Secretary arrived at the attendance figures.  That's OK, Tom, no hard feelings - I've even arranged for an escort service to your car tonight.  They're the two guys from Jersey.  Two visitors were introduced:  Rebecca Bedell, an art historian, and Linda Riddle.  The names of four newly elected members were announced:  Miriam Baltuck, Charles Prewitt, Roger Peebles, and Charles Druitt.  President Fiske, sounding just like his predecessor, Robin Brett, asked if everybody had paid his dues.  Upon hearing awkward mumblings from the gallery, he then shifted the subject to meeting notices, and announced the whole bundle for the USGS at Reston , featuring the bill of fare for the night's meeting, was lost.  The mumblings escalated to audible anxiety, and sparked a lively discussion.  Not to worry.  Careful analysis of our cost/benefit ratio with respect to meeting notices by Richard Tollo, our Treasurer, has led the GSW Council to change our contract for printing and distribution from JAW Computer Services, to the Mineralogical Society of America.  Our Council tells us this is the definitive stroke against the dreaded dragon of delinquent meeting notices.  Watch this space.  On behalf of James Clarke, Kathleen Krafft announced the Spring Field Trip to Calvert Cliffs was being led by Lucy McCartan and Buck Ward on May 9.

     Rebecca Bedell, introduced to the Society only moments ago, gave the first of two informal communications about her detective work on 13 paintings done in the mid-19th century by artists of the Hudson Valley school.  All 13 were praised by critics, but, are these paintings scientifically accurate, and, in fact, can we tell what place each one represents?  Being a captive audience, we aided our scholarly sleuth in typical GSW fashion - we jammed one of her slides in the projector, and stuck another one in sideways;  providing an unusual example of vertical bedding and horizontal trees defying gravity at some intriguing place in New England, now lost to science, but captured for posterity by a crackerjack artist.  Bruce Hanshaw concluded the informal communications with a short spiel about the oldest scientific congress in the world. In fact, the only congress that spawned a union.  No, this wasn't a provocative remark about Strom Thurmond, it was a plug for the 28th International Geological Congress to be held Washington, D. C., July 9-19, 1989.  Hanshaw says there will be 150 field trips, including Antarctica, and pleaded for local Geohosts, that is, a volunteer to help someone from a third world nation to register, as well as providing said registree with bed and breakfast.

     For the first formal talk of the evening, Jeff Grossman presented, "That which survives:  Relicts of the early solar nebula in chondrites."  Grossman says the ordinary chondrites are primitive rocks, chemically.  Spherical particles known as chondrules make up 75% of an ordinary chondrite; the other 25% is a dark matrix that surrounds the chondrules.  Ordinary chondrites are not only primitive, they are very ancient.  All of them seem to be 4.5 BY old, and all were formed at the beginning of the solar system, and therefore define this blessed event.  The individual chondrules took their own sweet time to form, however, and most of them needed another one million years to do the job.  Grossman made a convincing argument that the chondrules are remelted dust from the earliest epoch of the solar system, and a whole bunch of energy was necessary to do this melting.  In answer to a question by Ben Burton, we found out that the compositions of chondrules and matrix are different, but taken together they represent the composition of the sun.  I wonder if that means the chondrules and matrix got that wallop of energy from a punch in the solar plexus.  Further questions by James Galvin, Moto Sato, and E-an Zen.

     The second talk of the evening, "Crustal units in the western United States: Magnetic and gravity evidence,"  was given by Peter Johnson.  Showing us a jazzy slide of a many-splendored, magic Technicolor new map to be published in a few month's time, Johnson had his hands full telling us what all the colors meant.  Magnetic stripes never lie, and along the Juan de Fuca spreading center, the Pacific plate side is spreading faster than the other side, where the Juan de Fuca plate is taking it relatively easy.  On land, the exciting things are a couple of accreted terranes, one of seamounts, and the other of Mesozoic rocks.  Unfortunately, the magnetic stripes mysteriously vanish from the accreted terrane where the top of the downgoing slab disappears down the subduction zone.  This adds to the Technicolor, but wipes out the barcode, so Johnson may have to resort to GROUND TRUTH in order to sort things out.  He thinks some spreading centers were patchily covered by sediments which were then affected by low temperature metamorphism.  If this is true, Johnson believes the low temperature metamorphism would obliterate the magnetic minerals.  Mebbe so, mebbe so, but to find out he has to look at the eastern edge of the accretionary province in Oregon right where the Cascades are piled on top of it.  Lotsa luck, Peter.  Questions by Tilling.

     Richard Luth finished up the evening with his talk, "Effects of fluorine on phase equilibria and liquid structure in silicate systems."  Why fluorine?, he asked, and so did I - this was the second fluorine talk this year.  Luth explained by telling us that fluorine is a significant component in some igneous rocks, and the interactions of fluorine with magmatic liquid provides insight into the structure and thermodynamics of the liquid.  Previous workers have looked at topaz and rhyolites, but Luth likes a diopside-depolymerized system because he can then compare the effects of fluorine with those of water.  Sure enough, fluorine and water are a winning combination once again!  Luth found that in systems lacking aluminum tetrahedral coordination, fluorine will polymerize the liquid by complexing the network-modifying cations.  And in systems with aluminum, fluorine may either polymerize or depolymerize the liquid, depending on the relative stabilities of the complexes of fluorine with respect to cations involved in charge balancing, network forming, and network modifying.  Questions by Moto Sato and Benjamin Burton.

     President Fiske concluded the evening by stating, quote, "We will by golly get the notices for our September 30 meeting out to you all," unquote.  I DIDN'T GET MINE YET!  NEITHER DID HE!  The 74 in attendance were then adjourned, but don't ask me what time that was - I was too busy recounting the house so Dutro wouldn't pester me again.




September 30, 1987

     The 1166th meeting of the Society was called to order by a smoldering, sputtering, and fuming President Fiske at 8:19 PM.  The Cosmos Club, our twice-monthly host, landlord, and otherwise ambivalent ally, had sandbagged the start of the first Fall meeting by providing us with a slide projector from Toys 'R Us, but no lens.  It turns out that J. Thomas Dutro, Jr., that pesky past president who enjoys poking fun at the podium from the safe haven of the audience, was elsewhere in the building giving his OWN slide talk on the Grand Canyon, and he had the only decent projector the Cosmos Club owns.  As luck would have it, this peripatetic paleontologist provided tonight's program for the Society, one sure way for us to get a lock on the Cosmos Club's spartan stable of audio-visual equipment.  If you can't beat 'em, join 'em.  We all know that John Wesley Powell was one of the co-conspirators who helped conceive the Cosmos Club - who could miss his bust outside the door to this very auditorium?  I learned that in its early days, the Cosmos Club was nurtured at the bosom of Dolly Madison's house on Lafayette Square.  The Club cashed in when the President's Park became the focus of urban renewal for the new U. S. Court of Claims building.  The Club took the loot from selling Dolly's house to buy these magnificent digs, but apparently, out of some quirk of their ritual known only to them, they kept their museum-quality projector!  After all, if it was good enough for Powell, it ought to be good enough for us!  Apologies for the delayed start were extended to all by President Fiske, with the promise that one tardy beginning was one too many, and the Cosmos Club would be hearing plenty from him about their poor showing.  Staunch patrons of the beer buggy somehow seemed not to notice anything was amiss during their extra minutes of Miller Time.

     The minutes were read, and as long as Dutro was occupied elsewhere, and nobody else could remember what had happened five months ago at our last meeting on April 22, the secretary's report was accepted as read.

     Three guests were introduced:  Alexy Marchenko, from the Leningrad Mining Institute, and currently visiting professor in The Geology Department at George Washington University; Vladislav Ryaboy; and Jim Webster.  Five new members were introduced:  M. Sheila Marshall, Frank H. Jacobeen, Jr., Daniel Waltz, Brian E. Orlick, and Bruce Nelson.

     President Fiske announced the death of Lloyd Henbest, and the membership stood for a moment of silence in his memory.  A second announcement was about the new system of meeting notice distribution by the Mineralogical Society of America.  Apparently a few of us, including about 20 in the audience, GSW's President, and yours truly, have fallen through the cracks.  Please let us know if you've been missed, and we'll do our best to straighten it out.  Gene Robertson announced the nominating committee's slate of officers for the next term, to begin in December.

     For the first formal talk of the evening, Bevan French presented, "Vredefort Bronzite Granophyre:  Chemical Evidence for Origin of an Impact Melt."  French began by telling us the Vredefort structure was unique and controversial, and that it would probably remain controversial after his talk.  The Vredefort structure has a large, circular core of granites, 2.5 BY old, surrounded by a section of sediments and lavas, long-known to be characterized by upturning, overturning, and fracturing - and more recently, by shock features of metamorphism.  The question is whether the Vredefort structure with its granite core was formed by external causes, namely by a deep-seated impact of an extraterrestrial object, or by intrusion of a large body of magma which bulged up an asymmetrical mushroom-like structure.  It's sort of like asking what the crocodile has for dinner.  The youngest granite in the core of the Vredefort structure is the bronzite granophyre of the title, and it is the only unit not cut by pseudotachylite, so it is a key player in this saga.  The concept of an impact melt has going for it the generation of intense shock waves, pressures of several megabars, and temperatures of several thousand degrees centigrade.  After impact, the melt would move downward and spread out like a liner inside the impact crater.  The bronzite granophyre, Oh Best Beloved, forms some nifty long dikes with cooling rims, not inconsistent with an impact melt.  To look at the other option, namely a whomping big intrusion of granitic magma acting like a gigantic punch from below, we need to examine what would happen during assimilation of the wall rock, namely basalt, shale, and quartzite, by the parent magma, to see if that would give us the bronzite granophyre, as well.  French designed a computer program that takes a series of ingredients and compares them to the final product to see which model works better.  So what does the crocodile have for dinner?  It turns out the assimilation model doesn't explain the bronzite granophyre at all well, but the impact model can produce it with no sweat.  Questions by Mike Phillips, George Helz, Mike Ryan, Roger Nielsen, E-an Zen, Phil Greenly, Pete Toulmin, and Ralph Haugerud.

     The second talk of the evening, "1982-84 Volcano-Seismic Crisis at Campi Flegrei, Bay of Naples, Italy," was given by Robert Scandone.  Campi Flegrei is an area west of the Bay of Naples, which has experienced a lot of recent volcanism, beginning about one MY ago.  It is aptly named, as Campi Flegrei means "Burning Fields."  In a magnificent satellite photo we saw a breathtaking sweep from the Bay of Naples to the Isle of Capri, an area surrounded by an enormous caldera that has subsided to the tune of 3 km since the Plio-Pleistocene, and a vista dotted with gobs of volcanoes.  The only disquieting intrusion into our reverie from space is that 3 million people live there.  Measurements of the land movements have been made since 1800, with wonderful instruments like mollusk-bored marble columns on Roman ruins exposed at maximum uplift, serving as a talisman of some high times - dry ones, too.  In 1983 the uplift reached crisis proportions from Naples to the west coast.  Pozzuoli was smack in the middle of the seismic activity, and experienced the maximum uplift - most people bit the bullet and moved away.  The records since 1900 show there was a long interval of subsidence from 1905-1922, followed by the short, intense uplift of 1982-85.  The subsidence and uplift mirror each other, and always act in the same area.  Scandone believes we are dealing with an area collapsed by several episodes of volcanic activity, which is uplifted again by an increase in pressure.  Ben Burton asked if there was a big magma chamber beneath the Bay of Naples that was the culprit, and Scandone replied, "That's the big question."  Other questions by Moto Sato, Doug Rankin, and Tom Simkin.

     Richard Carlson finished up the evening with his talk, "Crustal Growth on the Oregon Plateau."  The Columbia Plateau, with its 3000-4000 feet of classic continental flood basalts, stands in contrast with the rocks of the Oregon Plateau, part of the Basin and Range Province.  The rocks of the Oregon Plateau are bimodal in composition, with both basalt and rhyolite present, and they occur in two phases, fractionated, and relatively unfractionated.  Just how did this come to be?  Carlson used reconnaissance sampling of young basalt flows, K-Ar dates, and geochemical isotope studies to help sort it all out.  The trend of older basalt to younger rhyolite from west to east led him to think the Juan de Fuca Ridge didn't like continents, so it went west, dragging the subduction zone with it.  Before about 18 MY ago, the basalts were arc-related volcanics, but after 18 MY they were extensional, and thinning of the crust about 15-17 MY ago let the flood basalts through.  About 10 MY ago the proto-Oregon Plateau opened up, characterized by some high-aluminum basalts from a nearly successful rift.  This scenario, along with some selected tender bits of mantle components to melt up and throw in the subterranean stew from time to time, gave Carlson everything he needed at just exactly the right place, and just when he needed it.  Questions by Eileen McLellan, Greg Harrity, E-an Zen, and Bill Haughn.

     President Fiske announced the program for the next meeting to the 86 in attendance, and adjourned us at 10:06 PM.




October 21, 1987

     The 1167th meeting of the Society was opened by President Fiske at 8:00 PM, with the announcement that this was a special occasion, a concurrent meeting with the Paleontological Society of Washington, otherwise known as PSW.  President Fiske introduced the President of PSW, Richard Grant, who was asked to call the meeting to order.  Grant complied obligingly, and extended an invitation for all to come to the next regular meeting of PSW on November 18 at the National Museum of Natural History.

     The minutes were read and approved.  Seven visitors were introduced:  Cherrie Oaks, Arthur Cohen, Jason Warner, Linda Welzenbach, Mark Govan, Carol Russel, and Laura Wilbur.  Practically all are students from the University of Maryland, an obvious sign that Peter Stifel's sabbatical year has ended.  Welcome back, Peter, and warmest greetings to all you Marylanders.

     For the first formal talk of the evening, John Pojeta, known to some as John Pojeeta, and others as Juan Pohayda, presented "Ascaulocardium armatum (Late Cretaceous) -the ultimate variation on the bivalve paradigm."  Pohayda says a paradigm is fancy word meaning "example," and Ascaulocardium is a pretty fancy clam, albeit a weird one.  Some commercial fossil dealers collected this thing that looked like twisted calcified spaghetti from Coon Creek, Tennessee, along with gobs of Cretaceous mollusks, for which the locality is famous.  After elaborately preparing this odd jumble of bent plumbing made of calcite, they brought it to Norm Sohl to find out what they had.  It turned out to be an uncanny clam, well outside the ordinary range of pelecypod shell architecture, which Pohayda and Sohl dubbed Ascaulocardium armatum, meaning "the bag-piper's heart."  Its living relatives, the clavagellid clams, live in the clear, shallow seas of subtropical to tropical shelf areas, whereas the bag-piper's heart is known only from Upper Cretaceous rocks of the Gulf and Atlantic coastal plains, and probably lived in cooler water.  Living clavagellid clams are popularly known as the "watering pot," or "salt and pepper shaker" shells.  That's because at the end of a calcareous tube there is a bulbous calcareous plate, perforated by a series of pores, or tubules, more or less similar to the spout of a gardener's watering can.  The whole affair looks remarkably like a marital aid that not even a Parisian purveyor of paraphernalia promising passionate pastimes would dare to display publicly.  So much so, in fact, that one species was named Brechites penis by none other that Jean Pierre Baptiste Lamarck, that risque French evolutionist of the 18th century who promoted the inheritance of acquired characteristics.  As if to show he was no sexist, Lamarck married four times, and named a second clavagellid clam Brechites vaginiferous!  By whatever name, these thoroughly modern clavagellid clams burrow, living vertically in a tube with the spout end down.  Burrowing is rapid and efficient, achieved by pumping water down and out the spout, with complete burial attained in only a few seconds.  What has this to do with its Cretaceous relative, the bag-piper's heart?  Juan Pohayda told us the four long tubes at the front end, the triple junction of tubes coiled around the central crypt, and the crown of tubes at the back end were all structures for hydraulic burrowing and deposit feeding.  So if the paradigm for this pelecypod stirred your prurient interests, remember, clavagellid clams really carried inside plumbing to an artform, and back outside again, information only GSW and PSW are privy to.

     So, one paradigm may really be the price for a private booth at our buddy Lamarcks's pay twalay.  Blame it on inflation.  Buddy, can you spare a paradigm?  Questions by Phelps Freeborn, John Repetski, E-an Zen, Gene Robertson, Peter Stifel, and Jack Frost.

     The second talk of the evening, "Conodont alteration in regional and contact metamorphic regimes, or How the world burns," was given by Anita Harris.  You remember Anita, she cooks conodonts to see what happens to these extinct beasts after a few thousand hours at 300 degrees C or so.  Harris is one of those old-fashioned girls who bakes in a traditional oven, shunning new-fangled devices like microwaves.  Besides, the search for new conodont recipes takes her to romantic and exotic places like Alaska, Mexico, the Blue Ridge, the Snake River Plain, and Massachusetts.  Short-order counter connoisseurs of conodont cuisine will remember the runaway success of Professional Paper 995, "Conodont Color Alteration - an index to organic metamorphism."  In this classic paper of a decade ago, Epstein, Epstein, and Harris substantiated conodont color alteration indices, or CAI, in the range of 50 to 300 degrees C, namely CAI 1 through 5.  Recently, Vivian Rejebian, in collaboration with Harris and Steve Huebner, turned up the wick to see what would happen to these babies at temperatures above 300°C, especially if some water-laden methane was tossed into the oven.  The experimentally altered conodonts are similar in texture to the naturally altered specimens from contact metamorphic rocks, but the experimental conodonts are much better preserved than the mangled, corroded, deformed, and fractured ones from regionally metamorphosed rock.  Tossing in a water and methane-rich mixture at 1/2 kbar shows first, that color alteration of conodonts is considerably retarded by wet swamp gas, and second, these fossils have CAI values and textures most like conodonts from hydrothermally altered or contact metamorphic rocks.  Therefore, CAI values of 6 to 8 cannot be used to assess temperatures of hydrothermally altered rocks, but they can be used as a valuable tool for targeting potential mineral deposits.  Though these wondrous little beasts may be the paleontological saviors of many metamorphic geologists, super-heated, super-squeezed conodonts usually self-destruct somewhere beyond chlorite grade in regionally metamorphosed rocks, or 600°C in contact metamorphic rocks.  To quote Harris, "Conodonts are a joy to behold, but not necessarily geologically forever."  Questions by Moto Sato, E-an Zen, Marcus Key, and Sorena Sorensen.

     Bruce Wardlaw finished up the evening with his talk, "Paleontology and geology of nuclear craters at Enewetak:  Results from project PEACE."  Starting off with a slide of a swollen, scarlet, steamy, mushroom-shaped nuclear cloud (hardly a peaceful symbol, except perhaps in the minds of the current administration), Wardlaw asked, "What does paleontology have to do with these Big Boys?"  It turns out that paleontology solved a big question in the minds of the Big Boys at the Pentagon, namely, what is the etiology of nuclear craters produced by megaton nuclear blasts?  The only places to look were Enewetak and Bikini - the only places where megaton nuclear devices were ever detonated under controlled field conditions.  Enewetak was lucky, it got two.  One, named KOA, produced a crater on the island, and the other, OAK crater, was in the lagoon under 14 feet of water.  Models from the Big Boys at Defense predicted the craters would deep and narrow, but they turned out to be wide and shallow, instead.  How come?  By comparing the stratigraphy of the craters with the biostratigraphy of an undisturbed section, these peaceful, patient paleontologists detected piping of sand from 600 feet down that wound up as sand volcanoes on the terraces of OAK crater.  This piping, combined with lateral flow at depth, greatly thinned the faunal zones beneath the crater in a systematic way.  In addition, our Peacenik paleontologists mapped the rubble flowstone that formed when the crater rebounded.  And a nice touch was their correlation of the deposits formed by the collapse of the ejecta flap, otherwise known as the "slap of the flap."

     Marcus Key asked why Casper Weinberger cared so much about these craters that he was willing to fund a megabuck study of these megaton military pits?  Wardlaw replied that Defense was more than passingly curious about the effects of a big blast on missile silos, for one thing, and the Survey's paragons of paleontological prowess were able to deliver on all counts.  May the FORCE be with you.

     President Fiske announced the program for the next meeting to the 84 in attendance, and adjourned us at 9:47 PM.



1168th Meeting, November 11, 1987.

Canceled due to snowstorm.



1169th Meeting: December 2, 1987

     President Fiske called 124 members of the Society to order for the 1169th meeting at 8:05 PM. The minutes of the 1167th meeting were called for,  read,  and approved.   Robin Brett inquired about the minutes of the 1168th meeting.   President Fiske informed Brett that a blizzard on the 11th of November had cancelled that meeting.   Brett asked why the Society had counted a meeting that had not occurred.   Fiske replied "Because a program announcement had been distributed."

     Guests G.  Ron Spencer and Catharine Toulmin were introduced. Newly elected members Deborah R. Jerez, K. Michael Cline, Michael D. Cavanaugh,  Sara Arav, Margaret Kasim and Albert Y. Sun were introduced.   President Fiske announced the death of Quentin Singewald and George Schoechle.   A moment of silence was observed.

     There were no other announcements,  informal communications or old or new business.   President-elect Douglas Rumble introduced the speaker,  outgoing President Fick Diske [correction: Richard Fiske, by Douglas Rumble], and complimented the wine served at the Cosmos Club.

     President Fiske's address was entitled "Two Worlds of Explosive Volcanism."   The title refers to subaerial and submarine eruptions.   The talk was a progress report of ongoing research into how volcanic detritus erupted below the ocean's surface is deposited.   The locally fossiliferous volcanic rocks of the Shirahama Formation of the Izu Peninsula in Japan illustrate that submarine pyroclastic rocks deposited near vents lack fine volcanic ash and contain pumice clasts about ten times the size of the largest lithic clast.   Theory and experiments suggest that such deposits represent a group of sedimentary particles with a similar terminal velocity in seawater.   Thus, submarine volcanic deposits that look poorly-sorted by size may be well-sorted with respect to terminal velocity.   Pumice erupted under water may be denser than pumice erupted into air,  because the hot gas in erupted pumice is replaced by seawater as pumice cools under water.   Large pumice blocks may float, partially degas and then sink when they become saturated with seawater. Fiske has measured the terminal velocities and densities of a large number of volcanic particles, and is planning to conduct experiments with his Device for Attenuation of Freefalling Tephra on particles collected from the volcanic rocks of the Izu Peninsula.

     No questions were asked. The meeting adjourned at 9:22 PM.

     Respectfully submitted,

     [signed Sorena Svea Sorensen]

     Based on notes of R. Rye




December 2, 1987

     President Fiske convened the 95th Annual Meeting at 9:42 PM in the John Wesley Powell Auditorium by hauling out the traditional Budweiser gavel.  Earlier in the evening he had opened the ll69th regular meeting and neatly dispatched Robin Brett's question about why THAT ONE was the 1169th, when there had been no 1168th meeting.  You will remember we had an incredible Veteran's Day surprise blizzard on the meeting date, November 11, with some motorists stuck on the Wilson Bridge for more than 20 hours.  Besides his outstanding presidential address, Fiske's parrying with Brett over why the invisible 1168th meeting had been sucked into another dimension may have been his finest moment of the evening.  But more about that later.

     Margo Kingston, the council secretary for 1987, read the minutes of the 94th Annual Meeting, which were approved.  Next, the report of the Meetings Secretary, yours truly, was read and approved.  Aannnnnd, back to Margo again with the Council Secretary's report.  The 1987 council will be remembered as the bunch who dragged the Society firmly into the computer age by handing over our business operation to the Mineralogical Society of America Business Office.  And, they ended the era of our being an outfit with no fixed address.  That is, until remodeling at the Cosmos Club in the fall of 1988 evicted the Society and put us on the streets again.

     Treasurer Richard Tollo brought us Season's Greetings with the good news that the Society's finances are still hanging in there.  In fact, we have a modest increase in our bank balance.  Tollo inherited a scenario in which we had doubled the dues, RIFFED some meetings, and farmed out the business operation to the private sector.  Sort of a cottage-craft prototype of a flexible freeze.  The Society expressed its thanks to Treasurer Tollo for his outstanding work in establishing GSW on a firm financial footing. 

     At this point it became evident we should have an auditor's report, but this tradition had somehow escaped President Fiske's notice.  He took full responsibility for the oversight, and promised to have somebody else, namely Dan Appleman, do the audit in time for a report at the next meeting.

     Warren Wood, Membership Chairman, reported his disappointment that only sixteen new members joined the Society during the year.  Apparently there is a perception that GSW is an elitist group, and some people are reluctant to attend UNLESS specifically invited.  As half the audience was wearing field boots, many in attendance were dumbfounded at the prospect of being considered elitist.  We need to work on our image, folks.

     Then Leanne Milton, Public Service Committee Chair, winged a report from memory on a marathon of activities.  One colleague had yet to return the (quote) "official black GSW science fair judging briefcase" (unquote) that contained all her data.  In the spring, nineteen GSW members judged ten science fairs in five different political jurisdictions.  Also in the spring, GSW shared a booth at the National Science Teachers Conference with George Mason University and the Association of Women Geologists.  It must have been a snug fit in that booth - a sight that the 249 earth science teachers who stopped by may not have been able to resist.  Leanne personally conducted four workshops on "How to prepare an earth science project for your science fair" to 111 participants.  Add to this a dinosaur bone loan program to pre-schoolers, and these are just the highlights. The Society gave a hearty round of applause for this committee's outstanding contribution to public service.  Then, just in time for Leanne's concluding remarks, a red-faced Phelps Freeborn returned the lost "official judging briefcase."

     Now it was time for the best paper awards.  President Fiske gathered his courage and confessed he hadn't retrieved the coveted silver bowl from last year's winner.  Even though Fiske bared his soul in front of us, this learned Society with a reputation for being elitist hissed him soundly.  READ THEIR LIPS.


     Best Paper Awards Chairman Josh Tracey began by telling us that of the 29 regular talks and ten informal communications, every paper had at least one table that couldn't be read from the middle of the room.  But the overall quality of the talks was tops, making the committee's job tough, indeed.  Chairman Tracey presented the Great Dane award to Ralph Haugerud for his informal communication about using the SEM to determine extraneous sources for argon in samples that were difficult or impossible to date by potassium-argon methods.  As this was an idea that came to Ralph only ten days earlier, the committee applauded him  for having the guts to bring a new, barely tested idea to the Society and presenting it so clearly.  Then came the Bradley awards.  Second prize went to Bevan French and Roger Nielsen for their talk, "Vredefort bronzite granophyre; chemical evidence for an impact melt."  The silver bowl and first prize went to Jeffrey Post and David Bish for their paper, "Manganese oxide minerals: some new insight from powder x-ray diffraction."  As one paleontologist remarked, "He even made todorokite sound interesting!"

     Putting on his third hat of the evening, yours truly represented the Sleeping Bear Committee, bestowers of our Society's highest accolade.  The other committee members, Dan Appleman and Dick Fiske, made some outrageous ploys for the award themselves, but of course they were ineligible.  In 1987 the Society did not lack for memorable quips, some planned, some spontaneous,

but "for the body of his work," the Bear and cup went to Dave Stewart.  In accepting, now three-time winner Stewart confessed, "I've said if I ever got this cup again, I'll retire!"  Promises, promises.

     President Fiske then thanked program chairman Glenn MacPherson for a good year.  The slate of officers for 1988 was accepted by acclamation, and newly elected President Rumble adjourned the meeting at 10:42 PM.

     Respectfully submitted,

     Raymond T. Rye