GSW: 1985
MEETING MINUTES
Geological Society of
January 9, 1985
President Hatch called the 1132nd meeting
of the Society to order at 8:08 pm. The minutes of the previous meeting were approved
as read. Two visitors were introduced - Geoff Plumlee of the USGS, and Claudia
Hackbart, a chemist with the NRC. The names of twelve new members were read,
and those present were applauded.
Gene Robertson then presented a short
communication on distinguishing between submarine lava pillows on the one hand
and pahoehoe toes, which may be produced subaerially as well as under water,
one the other. The former are blob-like in three dimensions and sometimes have
radial cooling cracks. The latter are cylindrical, ovoid only in cross-section,
and may have concentric structures. The talk was enlivened by the first Rankin
joke of the year, when Robertson showed a slide he described as "virgin
pillows mapped by Doug Rankin in
The first scheduled talk of the evening
"Thrust Fault Geometry in the Taconic Allochthon and Grenville Massif in
Western New England" was given by Paul Karabinos of
The second talk, by Paul Hearn of the USGS,
was entitled "Evidence of Alleghenian brine migration in the central
Appalachian Basin: Implications for lead-zinc mineralization." He showed
that thin bedded Paleozoic carbonates, especially dolomites, had, like
The last talk of the evening, by Pamela
Heald of the USGS, was entitled "Mineralogical variations in the Creede
district,
President Hatch announced that there would
be a next meeting, but that he had forgotten to bring the program. Dan Milton
gave the program, sort of, and the meeting was adjourned at 10:10 pm.
Attendance was 145.
Respectfully submitted,
[signed Rosalind L. Helz]
Geological Society of
January 23, 1985
President Hatch called the 1133rd meeting
of the Geological Society of Washington to order at 8:04 pm. The minutes of the
previous meeting were read; various members of the audience supplied your
secretary with the names of visitors and questioners I had missed, and the
minutes were approved as modified. Visitors were then introduced, including
Charles Mencken of the Oklahoma Geological Survey, Webbers of McAllister
College, Rachel Condon of the University of
The list of names of new members was then
read. The sole new member actually present, Emily Wegert of the
The first talk of the evening, by Bonnie
McGregor, was entitled "Similarities between submarine canyon processes
and those of a fluvial system." The speaker presented evidence that
submarine canyons strongly resemble subaerial erosion channels, particularly
those of intermittent streams in semiarid areas. She then suggested submarine
canyons formed in the same way, that is, by downslope movement of water-soaked
debris. This seems like an unimpeachable hypothesis. What other direction could
the stuff move? Questions by George Helz, Norm Hatch and Josh
Tracey, with a comment from Dan Milton.
The second talk of the evening, by Frank
Senftle,of the USGS, was entitled "The magnetic susceptibility of coal and
coal constituents." The speaker began by outlining the various types of
magnetic behavior possible: diamagnetic, paramagnetic, ferromagnetic and
superparamagnetic. (Note that, under this scheme, there is no such thing as a non-magnetic
substance.) Coal, left to itself, is diamagnetic; that is, confronted by a
magnetic field, it is faintly repelled by the whole thing. Students of coal
magnetics, not willing to let matters rest there, have developed two methods of
treating coal that make its magnetic properties more interesting. The first of
these involves grinding the coal in a metal-jawed rock crusher, producing
magnetic coal. Further investigation by Senftle and coworkers established that
agate mortars are no good for this purpose. The second method of producing
magnetic coal is to oxidize part of the pyrite in the coal to magnetite. The intensity
of the resulting magnetization is, not surprisingly, proportional to the amount
of pyrite present. Science marches on... Zen asked a
question, though not the most obvious one.
The third speaker of the evening was Joan
Fitzpatrick, USGS, talking on "Recent advances in X-ray
diffractometry." Before getting into that, however, she took us for a
stroll down
President Hatch read the program for the
next meeting and adjourned at 9:46 pm. Attendance was 81.
Respectfully submitted,
[signed Rosalind L. Helz]
GEOLOGICAL SOCIETY OF
February 13, 1985
President Hatch called the 1134th meeting
of the Geological Society of Washington to order at 8:04 p.m. The minutes of
the previous meeting were approved as read. Visitors were then introduced,
including Don Baker (post doc, USGS, Reston) Ed Ehrlich (from the Smithsonian)
Terry Cookro (USGS, Denver), Christopher Indorf (from Billings, Montana),
Donald Dingwell (from the Geological Lab), Nasr Widatalla and Exaud Kombe
(students at Howard University) and Steve Levin (from the University of
Maryland). President Hatch then announced the deaths of two members of the
Society, Linn Hoover and George Faust, and all present stood for a moment of
silence.
The first talk of the evening, by Eileen
McLellan, was on "Mineral assemblages as evidence of fluid availability
during retrograde metamorphism." She first looked at metamorphic assemblages
in the type Barrovian terrane of
In the course of this excursion, the
speaker deftly moved the boundary between metamorphic and igneous petrology
from its traditional position, to igneous petrology's 40-yard line (so to
speak) as she attributed to retrograde metamorphism the interactions that took
place between spinel and granite melt as the latter crystallized. Keep an eye
on Eileen: she'll make metamorphic petrologists of us all. Questions by Sorena
Sorensen, Dave Stewart, E-an Zen, Walt Kavilius, and Zen again.
The second speaker, Michael Kunk, spoke on
"40Ar - 39Ar age spectrum dating of biotite and
sanidine from Middle Ordovician bentonites of
The final talk of the evening, "The
petrogenesis of the intermediate lavas of the Ocate Volcanic field,
President Hatch then reminded the audience
that science fair judges are still needed and adjourned the meeting at 9:34
p.m. Attendance was 128.
Respectfully submitted,
[signed Rosalind L. Helz]
GEOLOGICAL SOCIETY OF
FEBRUARY 27, 1985
President Hatch called the 1135th meeting
of the Geological Society of Washington to order at 8:06 p.m. The minutes of
the previous meeting were read and approved. One visitor, Cathy Scanlon, of the
USGS at Woods Hole, was introduced. The names of six new members were read,
none of whom were present for the occasion.
The first talk of the evening, by John
Schlee of the USGS, was entitled, "The impact of multichannel
seismic-reflection data on understanding of continental margin structure and
stratigraphy." Schlee led off by saying that our current understanding of
the structure of the submarine portion of the continental margin of eastern
The second speaker, Nathalie
Valette-Silver, spoke on "Study of erosion history using 10Be
profiles. Impact of agriculture on erosion in the
The final talk of the evening, by Paul
Silver, was entitled, "Detection of an on-land spreading event at Cerro
Prieto." Cierro Prieto, a geothermal area in northwestern
President Hatch then noted that we still
need science fair judges and adjourned the meeting at 9:45 p.m. Attendance was
82.
Respectfully submitted.
[signed Rosalind L. Helz]
GEOLOGICAL SOCIETY OF
March 13, 1985
The 1136th meeting of the Geological
Society of Washington was called to order by Councilor John Repetski, who
chaired the meeting in the absence of the President, First Vice-president and
Second Vice-president. The minutes of the previous meeting were approved as
read. Several visitors were then introduced, including Edmund Barnes (DOE)
Chuck Fillmore (USGS,
The first talk of the evening, by Douglas
A. Bassett of the National Museum of Wales, was entitled "In celebration
of the geologic map." In this interesting historical lecture, Bassett
emphasized the unprecedented leap made by William Smith when he published the
first geologic map of
The second speaker, Philip Candela, spoke
on "Some petrological effects of magmatic vapor evolution: Bowen's Demon
is alive and well!" Before launching into his talk, he read as a text from
Bowen's Epistle to the Geologists, Chapter 16, beginning at the first verse:
"To many petrologists a volatile component is exactly like a Maxwell
demon; it does just what one may wish it to do." Candela then proceeded to
summarize the available data on the partitioning of minor and trace elements
between aqueous fluid and silicate melt. These results show that some elements,
like Cu and Zn, are strongly concentrated in the fluid phase, especially if it
contains chloride. Others, like Rb, Cs, Sr, Ba, F and B either are not strongly
partitioned, or favor the melt phase. Candela's title notwithstanding, it seems
they don't make demons like they used to. Questions by Sorena Sorensen,
Mary-Ann del Marmol and Pete Toulmin.
The last talk of the evening, by Juergen
Reinhard, was on "Cretaceous-Paleozoic relations in the northern
Mississippi Embayment." He and his colleagues have been looking at
paleosols and basal sediments that onlap the older rocks of the
Repetski announced the next program and
adjourned the meeting at 9:40 pm.
Attendance was 77.
Respectfully submitted,
[signed Rosalind Helz]
Geological Society of
March 27, 1985
President Hatch called the 1137th meeting
of the Geological Society of Washington to order at the now traditional 8:07
pm. The minutes of the previous meeting were read and approved. The following
guests were introduced: Jim Thompson (who, though mainly from Harvard, was
introduced as being from Princeton, Maine), Jim McClellan of Colgate U., Hal
Peregrine from the University of Bristol, Liz Downey from Amherst, John San
Felipo (USGS), Barbara Eisworth of Indiana U., Scott Truesdale (USGS), and Mike
Purucker. All were duly applauded by the assembled members.
The first talk of the evening, by John
Suppe of Princeton, was entitled "Present-day arc-continent collision in
The second speaker, E-an Zen, gave us
"Thoughts terranical, thoughts uplifting: some crustal inferences from
high-pressure plutons of the Western Cordillera." Zen has investigated a
series of calc-alkalic plutons in Idaho and Alaska. Several of these contain
epidote, which appears from its texture to be a primary magmatic mineral. Using
the occurrence of epidote and the total A1 content of hornblende to estimate
the pressure and temperature of crystallization of these plutons, Zen has
inferred (1) that these plutons crystallized at a depth of 50 km, (2) that
paleogeothermal gradients in the area were low (15°/km) and (3) that uplift
rates for these young plutons were high, averaging 0.5 mm/year over the past 60
m.y. The megamodel invoked was that continental collision, in areas of thick
crust, would produce further crustal thickening, anatexis and injection of
plutons, followed by rapid uplift, as continental "stitching" took
place. Concluding, perhaps wisely, that "igneous is bliss," Zen then
entertained questions from Sorena Sorensen, Linda Gunderson, Dave Stewart, Gene
Robertson (2 questions) and Jim Thompson.
The last talk of the evening, by Carl
Koteff, was entitled "Postglacial uplift: evidence for delayed isostatic
response." Koteff has made a meticulous study of the phenomena associated
with glacial retreat in New England. He concluded that the rebounding earth
acted like a completely uniform elastic medium, the complex bedrock geology
not-withstanding. Saying "Eat your heart out, E-an," he boasted of
rebound rates of 7 cm/year, rates which, if carried out, like E-an's, over a 60
million year interval would indeed leave E-an's plutons in the dust. The latest
wrinkle in glacial rebound, said Koteff, is that it didn't start until 5000
years after unloading began. He unveiled a quasi mathematical model which
explained this, beginning (appropriately) with the phrase "I assumed a
circular ice sheet." Questions by Linda Gunderson, Joe Smoot, Dave
Stewart, Jeff Severinghaus, Norm Hatch (2 questions), Dave Stewart again,
Warren, Steve Hill (concerned about the possibility of Clovis points among the
glaciers) Dan Milton (who took the occasion to announce that John Suppe would
be giving a talk at the USGS in Reston the following day) and E-an Zen.
The meeting was adjourned at 9:45 pm.
Attendance was 118.
Respectfully submitted,
[signed Rosalind Helz]
GEOLOGICAL SOCIETY OF
WASHINGTON - 1138th MEETING
APRIL 10, 1985
President Hatch called the 1138th meeting
of the Geological Society of Washington to order at 8:07 p.m. The minutes of
the previous meeting were corrected, and approved. Several guests were
introduced, including Mike O'Hara, Mike Duke, Bob Shock, Yusuf Nimri, and
Arthur Barber. They stood and were applauded by the assembled members.
President Hatch then announced the death of former member Bill Dempsey; all
stood for a moment of silence, after which Gene Robertson gave a brief speech
in honor of his former colleague and squash partner. The names of four new
members were then read.
Judy Ehlen, self-described as "the
talking podium," succumbed to pleas from the council for more informal
communications, and gave a report on the results of judging the regional
science fairs. There were lots of fairs and lots of earth science projects.
Accordingly, GSW awarded lots of prizes and certificates, to encourage the most
able and/or interested of the students, by letting them know that someone out
there cares about the earth sciences.
The first speaker of the evening, Robert
Hatcher of the University of South Carolina, spoke on "Scientific
justification for the Southern Appalachian deep drill hole." The
justification seems to be that, by drilling, we'll find out stuff that can't be
learned by just staring harder at the surface rocks. Specifically, the hole
would perhaps verify the idea that there has been large scale thrusting of a
thin skin of crystalline rocks westward over the North American plate. The hope
is that the hole would pass through the thrust sheet and fault, into the
autochthonous plate below. The only apparent obstacles are (1) obtaining
funding, (2) getting everyone to agree on a site, and (3) recognizing the
contact when we get there. There were plenty of questions, from Zen (2
questions), Norm Hatch, Gene Robertson (1 1/2 questions), Anita Harris (2
questions), Doug Rankin, Art Nelson (3 questions), E-an Zen (several more
questions), Bob Luce, and Art Nelson (again).
The second talk, by Sorena Sorensen of the
National Museum, was entitled, "Metamorphic geology of the Catalina Schist
Terrane: A Mesozoic subduction complex of Southern California." The
speaker introduced her talk on this eminently desirable field area by saying
that the Catalina Schist, a relative of the Franciscan melange, contained an
apparent inverted metamorphic sequence; that is, the lowest unit is of
blueschist facies, overlain by greenschist facies rocks, which in turn are
overlain by amphibolite and serpentinite. Blocks consisting of garnet,
hornblende, and pyroxene, found within the serpentinite, equilibrated at
600-700°C, 8-12 kb, or, as the speaker put it, down in the guts of the
subduction zone. There are even some feldspar-rich pegmatoids she thinks may
have formed by partial melting of the enclosing high-grade rocks. The
now-nearby blueschist rocks were, obviously, elsewhere at that point. Sorensen
suggested that the entire package was assembled tectonically prior to uplift
and emplacement, but exactly how is still not clear. Questions by Eileen McClellan,
Robin Brett, E-an Zen, and Moto Sato.
The last speaker of the evening, Charles
Bacon, (USGS, Menlo Park), spoke on "The precursory and climactic
eruptions of Mount Mazama and collapse of Crater Lake Caldera, Oregon."
Mt. Mazama, a stratovolcano in the Cascade Range in southern Oregon, had a long
early history of producing andesite and basalt. A shift to dacite and
rhyodacite domes, followed by a pumice fall and the Wineglass tuff, a welded
pyroclastic deposit, heralded the climactic event: the eruption that laid
Mazama ash all over the western and central U.S. and formed Crater Lake. The
main pyroclastic deposit is stratified chemically, the consequence of emptying
a zoned magma chamber, top first. The time span of all the dacitic-rhyolitic
activity was extremely compressed: one precursory flow still had a molten
interior, when it was cut by the caldera wall, which (core) promptly oozed back
downhill into the newly formed caldera. Who says you can't go home again?
Questions by Moto Sato, Jeff Severinghaus (2), Bill Burton, Laurel Woodruff,
and Jamie Allen.
President Hatch then announced the next
meeting and adjourned at 10:00 p.m. Attendance was 132.
Respectfully submitted,
[signed Rosalind L. Helz]
THE GEOLOGICAL SOCIETY OF WASHINGTON -- 1139TH MEETING
APRIL 24, 1985
President Hatch called the 1139th meeting
of the Society to order at 8:07 p.m. The minutes of the previous meeting were
read and approved. Several visitors were introduced, including Professor Yee,
Preston Cloud, John Rodgers, Larry Cathless, Thomas Broadhead and Lucas
Baumgardner. President Hatch then announced the GSW spring field trip, this one
to look at the Baltimore gneiss domes. The trip is scheduled for Saturday, May
18th, and will be led by Sakie Olson of Johns Hopkins. The names of three new
members were read and the one actually present, Alma Hale, was applauded.
Juergen Reinhart then gave two informal
communications. The first conveyed his daughter's thanks for having received a
GSW science fair award; her project was entitled, "Do you know what you're
drinking?". Reinhart next regaled the membership with the delights of
attending a meeting of the AAPG House of Delegates as a representative of GSW;
he recommended the experience to other members.
Doug Rankin gave a short communication
which he said was entitled, "Concerning clouds and their silver
linings." He did not wait for a laugh, but pressed on, showing slides of a
float trip down the Grand Canyon, which Doug had taken in company with Preston
Cloud and others. Rankin enjoyed the trip immensely, except for suffering the
pangs of beer withdrawal, when limited to a mere 2.67 cans per day. He closed
with a brief eulogy to Preston Cloud, which was all the more piquant because
the subject of it was alive and present in the audience.
The first more or less scheduled talk of
the evening was by Linc Hollister of Princeton, who spoke on "using Al in
hornblende as a geobarometer and why E-an Zen is all wrong," in preference
to his previously announced topic. Hollister has been working on the same
oddly-named and oddly-shaped plutons in Alaska that Zen has. He finds that the
total aluminum content of hornblende varies a lot within a given pluton, and
correlates well with other compositional parameters. Unfortunately, when he
plotted the total A1 content of these hornblendes against pressure estimates
based on other geobarometer assemblages, mostly from the metamorphic wallrocks,
the A1 content correlated embarrassingly well with pressure, too. Hollister
reluctantly concluded that Zen and Hammarstrom appeared to be right, but held
out the hope that it might be for the wrong reason. Questions by Eileen
McLellan and Gene Robertson. Comments by Zen (3- beginning with the remark that
Hollister was welcome, any time, to prove him (Zen) wrong like this), Pete
Stifel (who took the occasion to thank Hollister for serving on the Maryland
Geology Department review panel) and Eileen McLellan.
The second speaker of the evening, Preston
Cloud, began by telling the audience that rumors they may have heard of his
"imminent demise are wishful thinking." He then proceeded to his
topic "Precambrian is an anachronism!". He finds the term
objectionable for two reasons. First, he feels it has derogatory overtones,
inherited from its origins in the work of Murchison, who, while quite happy to
cope with the Cambrian fossiliferous strata, had no interest in the underlying
rocks, which he termed "interminable graywackes." Cloud felt,
correctly, that this was not nice. His second objection was that although the
base of the Cambrian used to coincide with the first appearance of recognizable
fossils, it no longer does. Diligent puttering around in the youngest
pre-hyphen-Cambrian rocks has turned up a meager but convincing fauna (or is it
flora?), the Ediacarian, in rocks 670-600 million years old. This, according to
the speaker, puts the term Pre-no hyphencambrian under a cloud. The balance of
the talk was spent debunking all pre-Ediacarian fossils while coping gracefully
with a projector gone bonkers. Question by Dan Milton and a quibble from Robin
Brett, who critized Cloud's pronunciation of Ediacarian.
The last talk of the evening, by Harold
Masursky, was entitled, "Recent advances in the exploration of Mars and
Venus." Recent photographs of the surface of Mars show it to have
volcanoes, lava fields, and yes, things that look remarkably like stream
channels. The current hypothesis concerning the latter is that they were formed
by liquid water, present on Mars only during thermal maxima. At other times,
like the present, H2O is present only as ice in the Martian soil.
NASA hopes the next landers will collect samples that will enable us to data
episodes of channel formation. Venus, with its dense and noxious atmosphere,
can be seen only in radar images. It has extremely rugged topography, including
linear folded mountain belts and two young volcanoes that may be active at the
present time. The topography suggests that plate tectonics doesn't work on
Venus, but apparently Murphy's Law does: in one of their lander experiments,
the Russians measured the density of the lens cap of a camera that fell into a
rock sampling hopper by mistake. This instance of uniformitarianism aside,
Masursky suggested that, geology-wise, there's no place like home. He then
speculated that the presence of living forms on earth might have significantly
affected earth's geologic history. There was much discussion, with
contributions from Jim Goddard, George Helz, Jim Goddard again, Alta Walker,
Moto Sato as the ferret redivivus, Preston Cloud, John Rodgers, Phelps Freeborn
(3 questions) and Dave Doan.
The meeting was adjourned at 10:29 p.m.
Attendance was 130.
Respectfully submitted,
[signed Rosalind L. Helz]
The Geological Society of Washington - 1140th meeting
May 8, 1985
Many moons ago, President Hatch called the
1140th meeting of the Geological Society of Washington to order at 8:09 p.m. At
least that's what my notes say. The minutes of the previous meeting were read
and approved. Several visitors were then introduced; their names appear in my
notes as Jeff Tuttle, Suzanne and Jerry Pavich, and S. and Woody Turner. The
names of two newly elected members were then read.
The first half of the meeting appears to
have been taken up by announcements and short communications. Judy Ehlen made
two announcements, the first concerning GSW's spring field trip on May 18, the
second summarizing the results of GSW's judging all the earth science projects
in the regional science fairs. We gave out 8 best-of-fair awards, 58
certificates, and 2 best-of-season awards.
Laurie Wallace, local AAPG representative,
then announced that the AAPG will be participating in next year's Boy Scout
Jamboree. Anyone interested in manning the AAPG booth, to be located in the
"geology merit badge" midway, should contact Wallace. E-an Zen then
solicited letters written in support of Andrei Sakharov.
In the first short communication, Peter
Lytle issued a travel advisory to the effect that the Trenton prong is
upside-down. It appears that the presence of unrecognized thrust faults may
render the area hazardous to geologists in general and Gene Robertson in
particular. Lytle said that the evidence for these faults did not come out of
new mapping, but was the result of staring at the old folio maps for a long
time.
A second unscheduled communication,
informal but not short, was given by Charles Baskerville, on the subject
"Rockfalls and airbursts in mountainous areas." The speaker described
a large rockfall which occurred at Smugglers' Notch, in Vermont, in July of
1983. The rockfall was (in part) witnessed by a jogger, who heard a sonic boom,
then saw the cliff crumble. As the debris shot past him, he ceased observing,
preferring to fall down, while praying hard. Some of the blocks shot all the
way across the valley. There was no smooth slip surface on the cliff face where
the fall originated, and no rain associated with the rockfall, so Baskerville
suggested that a downward, nontornadic, short-lived airburst was responsible
for the event.
President Hatch then announced the death of
Frank Grimaldi, and the audience stood for a moment of silence.
The first scheduled talk of the evening was
by Robert B. Jacobson, on the topic "Landslide magnitude and frequency,
Buffalo Creek, Marion County, West Virginia." The speaker has dated
particular slides by looking at tree rings in the oldest trees on a given
slump. When one plots slump frequency and size against time, it appears that
most slumping occurs during long wet periods, especially in springtime. Science marches on.
Questions and/or comments by Baskerville
(who said landslides worked the same way in the Green Mountains), by E-an Zen,
and by Meyer Rubin, who asked, "Where are all those radiocarbon dates I
did for you?"
The next talk on "The Tertiary(?)
dinosaurs of the San Juan Basin, New Mexico," was by James E. Fassett,
USGS, Reston. He began by noting that the famous end-of-Mesozoic iridium
anomaly does appear to be very widespread, and does coincide with mass
extinctions in the marine environment. However, recent work by the speaker on
several sections of continental sediments in New Mexico show that dinosaur
remains, some of then quite complete, and Paleocene pollen both occur
pervasively in the Ojo Alamo Formation of New Mexico. Perhaps dinosaurs were
not as allergic to iridium as has been previously thought. Questions by Jamie
Allen, Frank Whitmore, Peter Krantz, Doug Kinney, E-an Zen, and, again, Frank
Whitmore.
The last speaker, Jamie Allen of the
Smithsonian, spoke on "The Colima graben, a Pliocene to recent rift of the
Mexican volcanic belt, southwestern Mexico." The Colima graben is a
structural basin formed at a triple junction. The rift valleys contain a
curious assortment of lavas, including calc-alkalic rocks, phlogopite-hornblende
lamprophyres, and basanites, evidence that the underlying lithosphere is a
complex and busy place. The speaker predicted that, if present trends continue,
the chunk of Mexico on the west side of the triple junction will be rifted off,
as Baja California has been. Judging from the newspapers, he was right.
Question by Dan Milton.
The meeting was adjourned at 10:15 p.m.
Attendance was 84.
Respectfully submitted,
[signed Rosalind Helz]
The Geological Society of
Washington -1141st Meeting
September 25, 1985
The 1141st meeting of the Geological
Society of Washington was called to order by Vice-president Robin Brett at 8:07
pm. The minutes were read and approved, more or less. Many guests were then
introduced, including Dr. Mohammed Bensaid, the Director of the Geological
Survey of Morocco, Dr. Mahmood of the School of Mines in Rabat, Robert Luth,
Page Chamberlain, Mr. Guy Chamond, Dallas Swain (University of Sydney), Patty
Walsh, Ralph Haugerud, Martha Davidson, Shirley Turner, John Latter, from New
Zealand, Dick Kerr, a writer for Science magazine and Igor Eberstein.
Brett then announced the death of Al
Chidester and the assembly stood for moment of silence.
This was followed by a complaint from E-an
Zen to the effect that the beer glasses were too small. Brett then read the
names of several new members, none of whom were present, and announced that the
SEPM was sponsoring a field trip on October 11-13, to visit the Taconian
clastic sequence in Virginia and West Virginia, if anyone was interested.
The first talk of the evening, by Michael
Ryan of the U.S. Geological Survey, was on "The mechanics and
three-dimensional internal structure of Kilauea Volcano." Extensive
monitoring of earthquakes and surface deformation, carried out at Kilauea over
many years, allows us to infer a great deal about the internal workings of this
volcano. At present Kilauea appears to have a complex magma reservoir, which
behaves like a plexus of sills, in which individual sills can fill and empty
separately. Finite element modeling by Ryan makes it possible to constrain the
location, size and attitude of the sills (or dikes), by matching calculated
ground deformation patterns with those actually observed. Questions by
anonymous, Bob Tilling and Dave Stewart.
The second speaker, Stephen Obermeier of
the USGS, spoke on "Holocene earthquakes in the Charleston area, South
Carolina." One of the lesser consequence of the earthquake that hit
Charleston in 1886 was that the area hardest hit by the quake was found to be
pockmarked with "sandblow craters." These small craters formed when
water-saturated Pleistocene beach sands became liquefied during the quake and
erupted through the soil. A search of the area for older populations of
sandblow craters has turned up three, one dated at 1200 years b.p. and two
older-sets. Each set is inferred to have been produced by an earthquake. The
distribution of fossil sandblows suggests that some of these older quakes
were-even larger than the 1886 event. Questions by Phelps Freeborn, George
Helz, Gene Robertson, Craig Sprinkle, Dal Swain, Bob Tilling and E-an Zen.
The last talk of the evening,
"Basaltic meteorites and their parent planets" was by Harry McSween,
Jr. of the University of Tennessee. McSween presented evidence that two classes
of meteorites, the eucrites and the shergottites, must have come from two
different parent bodies. The eucrites are breccias with igneous clasts, which
formed at very reducing, completely anhydrous conditions about 4.6 b.y. ago.
The shergottites are more like terrestrial basalts in mineralogy and texture.
They formed at the moderately oxidizing conditions of the FMQ buffer, in the
presence of minor water, about 1.3 b.y. ago. The spectra from one particular
asteroid (4 Vesta) match those of the eucrites very closely, leading McSween
and others to conclude that the eucrites came from 4 Vesta. The shergottites
must have come from a larger planet, which had a much more extensive period of
igneous activity. McSween, noting that the list of candidate planets was quite
limited, suggested Mars. This provoked a lot of discussion, with questions by
Dan Milton, Leann Milton, Sorena Sorensen, Dave Stewart, Bob Tilling and Robin
Brett, and an untold number of ethnic slurs.
The meeting was adjourned at 9:50 pm.
Attendance was 116.
Respectfully submitted
[signed Rosalind Helz]
Geological Society of
Washington - 1142nd Meeting
October 9, 1985
President Hatch called the 1142nd meeting
of the Society of order at 8:07 p.m. The minutes of the previous meeting were
read, uncontested. Three visitors were then introduced: they were Sam Frazer (a
new member), Bill Siefried (University of Minnesota), and Laurie Webber (from
Los Angeles). The names of 12 new members were then read, and the three
actually present, Ralph Haugerud, Gwen Russell and David Dantzler, stood and
were applauded.
The next item of the agenda was an informal
communication on wave action along the New Jersey coast, as observed during
Hurricane Gloria. The gist of this well-illustrated talk was that the direction
of longshore movement of water, sand and flotsam changed from northward to
southward as the hurricane moved north. There were several questions. The
first, by Bob Tilling, was easy: he wanted to know the name of the speaker.
"Cyril Galvin, and I've been a member of this society for over 20
years" replied the speaker, in a tone of voice that suggested he knew
whereof he spoke. He then fielded other questions, including one each from Dan
Milton and Vernon Bride, and two fetching queries from Robin Brett.
The first formal talk of the evening, by
Prof. A.J.R. White of La Trobe University, was entitled "Two-mica granites
of southwestern North America are not S-types." White's basic thesis was
that, as he and Bruce Chappell originated the terms S- and I-type granites, he was
uniquely well-qualified to decide whether other geologists were using the term
correctly. Which, in White's opinion, they were not. To work on granites
properly, according to White, it is first necessary to group them into suites.
A suite is a bunch of granites which in the U.S. would be termed
"consanguineous;" however, said White, "in Australia, we would
just say they were bloody similar." The S-suites of Australia are all
darkish gray rocks, which are strongly peraluminous, with cordierite almost ubiquitous.
In the SW USA, by contrast, there are individual 2-mica granites that are
weakly peraluminous, but as the more mafic granites associated with them are
not peraluminous and cordierite is absent, the suite is "I" and not
"S," said White. There was much discussion, with questions from E-an
Zen (2), Eileen McLellan, Ken Towe, Pete Toulmin (who asked "Why do
Australian sediments melt better?" and was told "We bury 'em
deeper."), Zen again (2 more questions), Don Dingwell (several questions),
Dick Tollo from GW, a blue shirt from the U. of Maryland, and Robin Brett, who
lamented the lack of simultaneous translation from Australian to American.
The second talk of the evening, by William
Schopf of UCLA, was entitled "Recent studies in Proterozoic and Archeozoic
paleobiology," or, as the speaker modestly put it, "All I'm going to
talk about is the origin of life." He then blamed Ken Towe for his
presence onstage and pleaded for a beer, which was brought to him. Launching
into his subject, Schopf remarked that what he was about to say was based on
very new, unpublished results, so hot that they should not be considered
definitive, or even correct, the field of Precambrian paleobiology being in a
state of great flux. This was contrasted to Phanerozoic paleobiology,
characterized by the speaker, with evident disdain, as consisting of "Tom
- Dutro-type deposits." Well. It seems that the Warrawoona strata of
Australia and those of the Onverwacht Group of South Africa, dated by other
means as 3.4-3.5 b.y. old, contain round microfossils (that is, little round
things), filamentous microfossils (little stringy things) and stromatolites
(bigger round things with concentric layers), in addition to perfectly
sensational ripplemarks and the like. The speaker concluded that life had begun
by then, if not earlier. There were many questioners. The first was A.J.R.
White, who wanted to know how a bloke who couldn't even speak Australian
managed to get a beer delivered to the podium. The speaker did not answer that
question, but all subsequent questioners including Joe Smoot, Sorenea Sorensen,
Bevan French, E-an Zen and Moto Sato were treated to very long answers indeed.
The last speaker of the evening, Tom
Simkin, spoke on "Morphogenetic comparison of Galapagos volcanoes with young
EPR seamounts." Recent improvements in the devices that permit us to
determine underwater topography give us much more detailed picture of the shape
of seamounts than has been available hitherto. This class of volcanoes, the
most abundant and least studied in the world, are characterized by steep flanks
and broad summits. The summit regions usually contain calderas, but may simply
be flat. Subaerial volcanoes in the Galapagos have similar shapes, in contrast
to the classic shield volcanoes of Hawaii, for example. In the Galapagos, the
flattish, squared-off shape results from the tendency of lava to be erupted
principally from ring fractures that lie just outside the boundary fault of the
summit caldera, thus broadening the summit and oversteepening the upper flanks
of the volcano. Simkin suggested that seamounts owe their shapes to the same
process. Questions by Dan Milton, Bob Tilling, Bevan French, Moto Sato, Pete
Stifel, and Peggy Appleman.
President Hatch adjourned the meeting at
10:22 p.m. Attendance was 105.
Respectfully submitted,
[signed Rosalind L. Helz]
Geological Society of
Washington - 1143rd Meeting
October 23, 1985
Vice-president Brett called the 1143rd
meeting of the Society to order at 8:08 p.m., by saying "would the beer
swillers at the back please sit down!" They did, eventually, and the
minutes of the previous meeting were then read and approved. Several guests
were announced, including Laurens Wals from Belgium, Eric Christopherson(?),
Alder Jones and Federico Solano of Howard University, and Ron Parker, of the
USGS, Reston.
Brett then called for the first slide,
which showed a bear on the rocks. This is the proposed new logo of the Society,
and is more appropriate than you may think. The logo will appear on T-shirts,
to be available in tan, yellow, gray, and blue, in small, medium, large and
Xtra large sizes. Brett asked those who would be interested in acquiring such a
shirt to raise their hands, and a majority of those present did so. Brett then
read the proposed slate of new officers for the Society, to be elected at the
annual meeting in December.
This was followed by a short communication
from Russell Campbell on recent landslides in Puerto Rico. The landslides were
triggered by torrential rains, of up to several inches an hour, with 25 inches
falling in 24 hours, and they caused hundreds of deaths, and the usual
impressive wreckage. Questions by anonymous, Phelps Freeborn and Peter Stifel.
The first formal talk of the evening, by
Joe Smoot, USGS, Reston was entitled "Fluvial styles in the early Mesozoic
Newark Supergroup and their paleoclimatic implications." It seems that
there are fluvial sediments of Triassic age in a series of basins that runs
along the east coast from Nova Scotia to South Carolina. When a dedicated
connoisseur of such things looks very closely at these fluvial sediments, they
can be seen to differ from place to place, in ways that suggest that the
northern basins had a drier climate than the southern basins, except, of
course, for some exceptions. Questions by Phelps Freeborn (2), E-an Zen (2),
Pete Stifel and Moto Sato. These were followed by a comment from Brett to the
effect that he found it "terrifying that Newark New Jersey area in the
Triassic was so much like central Australia today," a remark which suggests
our Veep can't tell a dinosaur from a kangaroo.
The second talk of the evening was by A.K.
Sinha, on the subject "Thermal and tectonic evolution of the Central and
Southern Appalachians: Evidence from age, origin and distribution of igneous
rocks." One gathers that Sinha has taken on the task of dating every
pluton in .the Appalachians. The plutons, according to Sinha, fall into three
groups. The oldest group have ages of 520-440 million years. This
80-million-year spate of plutonism was followed by a 5-million-year gap, and
that in turn followed by another 75 million years of intrusive activity, from
435-360 m.y. ago. Thirty million years of quiet on the igneous front preceded
the Hercynian granitoids, which appeared over 70 million years, from 330-260 m.
years ago. The meaning of it all was left to the imagination of the audience
but we were so stunned by his display of industry that nobody asked any
questions. Not even how he picked the gaps between the age groups.
The final talk of the evening was by Grant
Garven of Johns Hopkins. His title was "The hydrogeology of stratabound
ore genesis in sedimentary basins," but we could tell what he meant
anyway. He explained that the movement of groundwater through regional aquifers
can, under favorable circumstances, produce stratabound ores along the edges of
sedimentary basins. If ground water flow rates are too low, nothing happens; if
they're too high, all you get is lots of cold water, but if they're just right
you get warm water and, eventually, an ore deposit. It only takes a million
years or so. There were questions and comments by George Helz, Joe Smoot, Robin
Brett (who said he was relieved to discover that formation of an ore deposit
was not an unnatural act after all), Tom Dutro, Jacob Gair, Blair Jones, and
Marilyn Estep.
Brett then read the program for the next
meeting and adjourned at 10:22 p.m. Attendance was 108.
Respectfully submitted,
[signed Rosalind Helz]
Geological Society of Washington - 1144th Meeting
November 13, 1985
President Hatch called the 1144th meeting
of the Society to order at 8:04 pm. The minutes of the previous meeting were
read and approved. Several guests were then introduced, including Brian Toon,
John Russell, Ralph Lanham, Jim Crowley, Dzu Du Wong (?), Jim Somebody from the
EPA, Jeff Tuttle, and John and Martha O'Keefe.
Next Cathy Davis, president of the
students' Geological Society of the University of Maryland announced that they
were selling T-shirts to raise money, that a display of the T-shirts was at the
back of the room, and that they would be happy to take orders for same.
Treasurer Klaus Schulz then provided the
audience with a sobering look at our fiscal past, present and future: In the
past 10 years, Society expenses have increased 89%, while dues have remained
constant. At present, we are stone broke. As for the future, the Society
requires a major transfusion of funds if it is to continue in anything like its
present style (e.g., having beer at meetings). President Hatch followed this
report up by reading a proposal, in the form of an amendment to the GSW bylaws,
to double the current dues for all categories of membership. If approved, this
measure, plus some extra tax-deductible contributions from the more dedicated
beer drinkers, will keep the Society flush (so to speak) until 1988, or
thereabouts. The amendment will be voted on at the next meeting. Hatch further
announced that there were cost-cutting measures already approved by the
council, including reducing the number of meetings per year from 14 back to the
traditional 12, and restricting the privilege of a free dinner, at the
Society's expense, to out-of-town speakers only. There was some discussion from
anonymous, Gene Robertson and Robin Brett.
The first more or less geologic item on the
agenda was a short communication from Gene Robertson, entitled "Jelly-roll
tectonics" featuring Gus the Gnome and/or his magic arrows as the prime
movers of thrust sheets. Robertson showed in a series of cartoons how Gus (or a
large black arrow) could be invoked to slide a thin layer of sediments for any
given distance over younger rock. A suitably placed asperity (or lump) in the
fault plane would produce a fold, and two such asperities would produce a
regular jelly roll of sediments, assuming Gus did not notice the problem and
stop pushing. Robertson then denounced "jelly-roll tectonics" of this
sort as being physically unsound, and claimed that, in many geologic
cross-sections where folded thrusts have been invoked, the relationships can be
explained without them. A call for questions produced-first, a declaration from
Doug Rankin that the particular cross-section on Robertson's last slide did too
require folded thrusts and could not be explained otherwise; the second
comment, from Robin Brett, was a dubiously relevant point-of-information on the
significance of the term "jelly-roll" in jazz.
The first formal talk of the evening, by
Charles Officer, was entitled "Volcanism and Cretaceous/Tertiary
Extinction." Officer, like many others, has been looking closely at any
and all phenomena associated with the K/T boundary. These include elevated
iridium levels, microspherules of obscure origin and mineral grains with shock
features. Officer and friends suggest that all of these can be explained as due
to terrestrial volcanism in general and the eruption of the Deccan Traps in
particular. The extinctions at the K/T boundary are then explained, not as the
result of months of darkness following a giant meteorite impact, but as the
consequence of world-wide acid rain and elevated U-V radiation. The ammonites
got pickled and the dinosaur eggs fried. This suggestion was discussed, with
varying degrees of skepticism, by Jim Fassett, Charles Morey, Dan Milton, Bevan
French, Bill Hauser and Robin Brett. The lack of extinctions associated with
larger episodes of plateau-basalt volcanism in the Jurassic was, oddly enough,
not discussed by anyone.
The second speaker, Lucy McFadden of the
University of Maryland, spoke on "Mineralogy and Petrology of Near-Earth
Asteroids." There are 84 known asteroids in planet-crossing orbits, many
of them even now in orbit between the earth and Mars. The speaker has studied
reflection spectra of some of these, to try to determine their mineralogy, and
compare it with the various classes of meteorites. Asteroids corresponding to
carbonaceous chondrites and to basaltic achondrites have been identified and
are considered possible sources for these types of meteorites. Questions by
John O'Keefe, Robin Brett, Dan Milton and Phelps Freeborn.
The final talk of the evening, by Allan B.
Tanner, was entitled "Hope for estimation of indoor radon hazard potential
from aeroradiometric and geologic data." It has long been known that
breathing radon is hazardous to one's health, and radon exposure in obvious
problem areas, such as uranium mines, is monitored and regulated. More
recently, it has become evident that radon can be a problem in private homes as
well, especially in tight, well-insulated houses on nice, solid crystalline
bedrock. The radon is produced in the underlying rock and seeps in through the
basement or, sometimes, comes out of sink faucets and showerheads with the
groundwater. The house of choice, radon-wise, is flimsy, drafty, and built on
young sediments or artificial fill. Isn't geology fun? There was much
discussion, with questions from Fred Siegel, Doug Rankin, Gene Robertson, Wood,
Bob Neuman, Bevan French, Bob Tilling, and anonymous.
President Hatch adjourned the meeting at
10:25 pm. Attendance was 108.
Respectfully submitted,
[signed Rosalind L. Helz]
The Geological Society of
Washington - 1145th Meeting
December 11, 1985
President Hatch called the 1145th meeting
of the Society to order at 8:04 pm. The minutes of the previous meeting were
read and approved, and two visitors, Jim Thompson and Tony Greemer (?) were
introduced. Next the secretary read the names of seven newly elected members of
the society, none of whom was in attendance. Jane Hammarstrom then announced
that GSW Tee-shirts (which shows an irritated-looking bear on the rocks) are
available, at a cost of $9.00, plus $1.00 shipping.
Next treasurer Klaus Schulz presented a
series of slides illustrating the need for a sizeable increase in Society dues,
if the Society is to maintain to its present style. President Hatch noted that
alternatives to the dues increase, such as moving the meetings to cheaper
quarters and/or eliminating beer at the meetings, were even worse, and re-read
the text of the proposed motion. The proposal carried unanimously, with only a
few snide remarks about the competence of the previous treasurers, plus one
obscure dig at Tom Dutro.
Rob Koeppen then gave an informal
communication on recent volcanic(?) activity along the Chilean-Bolivian border.
He showed an extensive set of slides of a cluster of snowy Andean volcanoes,
perched on this border. One of these peaks had a series of small white puffs
rising from it, indicative of steam explosions, or the election of a pope, or
something. Koeppen's conclusions were also somewhat up in the air, as he was not
able to get closer to the volcanoes than 25 km.
Next on the agenda was Hatch's presidential
address, but before that could happen, it was necessary to find someone to
introduce him. Vice president Brett had fled to San Francisco and second-vice
president Pavlides had arranged to be in the hospital for the occasion, so
councillor John Repetski did the honors. Repetski introduced himself first, as
a faceless paleontologist. He claimed to know practically nothing about Norm
Hatch, except that Norm has worked only to the east of the western border of
Massachusetts, and that he likes southern fried catfish (a reaction to New
England cuisine, no doubt) with his cheap beer.
Thus launched, President Hatch then gave
his address, entitled "Some speculations about a deformed Lower
Devonian(?) sedimentary trough in western New England." He began by noting
that unraveling the history of mountain belts, as he has been doing on the
northern Appalachians, generally attracts more hard-rock geologists than
sedimentologists, even though some of the rocks may have started out as lowly
sediments. Hatch then proceeded to show that if one studies the Siluro-Devonian
metasediments of Vermont as mere sediments, one can make a case for scrapping
some old formation definitions, remapping the area and considerably
re-interpreting the geology. He concluded that changes in the sedimentary
section from east to west across Vermont were facies changes, with the
sediments originating in the east and fining westward. The exact source area is
unknown and the age of the sediments uncertain, so more work, of a
sedimentological/paleontological nature, is indicated. The talk was illustrated
with a series of slides of metasediments in outcrop, one of the most
fascinating features of which, for the non-sedimentologist, was use the use of
a different pen used as scale in each slide.
Hatch then announced the program of the
next regular meeting (January 8) and adjourned at 9:22 pm. Attendance, strictly
speaking, is unknown, as the audience rushed to get to the beer before I could
make a head count, but roughly 120 people attended.
Respectfully submitted,
Roz Helz
The Geological Society of Washington
93rd Annual Meeting
December 11, 1985
President Hatch, having recovered from the
ordeal of giving the presidential address, called the meeting to some semblance
of order at 9:29 p. m. Kathy Krafft, the council secretary for 1985, read the
minutes for the 91st and 92nd annual meetings, which of course were approved as
read, as at that point nobody had the foggiest idea whether they were right or
not. The report of the Meeting Secretary for 1985 was also read and approved.
Then Krafft came on again, with the Council Secretary's report for 1985.
The sister act was finally broken up by
Klaus Schulz, giving the Treasurer's Report. He gave us an elaborate
presentation, complete with slides, showing us how broke we were, and how much
broker we would be without a dues increase. This was all somewhat anticlimactic
as we had already approved the requested dues increase, just prior to Hatch's
presidential address.
Mike Foose reported that the
Auditing Committee had found the books in order and the Treasurer's Report was
accepted. E-an Zen then moved that the treasurer be thanked for his heroic efforts
to bring fiscal sanity to GSW, which he was.
There was no formal report from the
Membership Committee, as its chairman, Fred Simon, was out of the country.
There was ditto from the Public Service (Science Fairs) Committee, as its
chairman, Judy Ehlen, was ditto. President Hatch noted that she had done an
outstanding job and we voted her a word of thanks in absentia.
Then Leanne Milton, for the Earth Science
Education Committee, told us about her efforts to get speakers to go to the
public schools and tell the kids about geology. "It is a wonderful
experience" she informed us. "The kids treat you like the expert you
are. It's nothing like GSW"
Next came the Centennial Committee report
by Gene Robertson. The Committee has undertaken to write a history of the 29
founders of the Society, complete with pictures and references, and Gene has
been hard at it. So far he has discovered that GSW formed in 1893, by splitting
off from the Philosophical Society, the occasion for the split being a
complaint by the president of PSW that entirely too much time was being spent
on geological talks.
Then came the Awards Committee. The first
Bradley Award of $200 and a year's possession of the silver bowl went to Harry
McSween, Jr. for his talk on "Basaltic meteorites and their parent
planets." Second prize went to Douglas A. Bassett for his talk "In
celebration of the geologic map." Honorable mentions went to Eileen
McLellan and Charles Officer. The Great Dane Award was bestowed twice, on Gene
Robertson (for Gus the Gnome) and Russ Campbell (for Mudslides in Puerto Rico),
with an honorable mention for Cyril Galvin.
Last, but not least, came the Sleeping Bear
Award. Or should have come. Instead, we had E-an Zen who said he had only
volunteered to read the report in Chairman Robin Brett's absence. "I am
merely deputy emergency chief for emergencies", said Zen. "All blame
and lack of judgment belongs to me unless there is an outcry", in which
case, presumably, it would revert to Brett. After extensively pillaging
Bartlett's familiar quotations on the subject of humor, Brett decided,
humorlessly, that there had been none at GSW in 1985. The true motive for this
decision became clear when Zen announced that Brett would be keeping the cup
himself, "for safekeeping', clearly a backhanded way of awarding the prize
to himself.
Hatch then thanked programs chairman Danny
Milton for a good year.. The slate of 1986 officers was accepted by
acclamation, and newly elected First Veep Fiske adjourned the meeting at 10:34
p.m.
Respectfully submitted,
[signed Rosalind Helz]