GSW: 1992 MEETING MINUTES

Minutes of the Geological Society of Washington

January 8, 1992

The 1220th meeting of the Geological Society of Washington began at 8:03 pm January 8. The following guests were introduced: Beverly Johnson, Sampath Tirumala, Shobha Kondragunta, and Frank Masdath. President Huebner reported the mid-December death of John T. Hack, who was GSW president in 1966. President Huebner initiated the questionable policy of observing awkward pauses while waiting for absent new members to stand up. Jeff Grossman gave an informal presentation on the inflating length of the secretary's report. I regret that I don't have time to reiterate the salient points of his report. Three unidentified people, R-an Zen, Bruce Doe, Robin Brett, and Beven French asked questions.

P. Robin Brett, in 24 minutes, presented the theory that anhydrite decomposition caused by a K-T boundary bolide impact in Chicxulub, Mexico had profound effects on atmospheric chemistry causing ozone depletion, global cooling, acid rain, inhibition of photosynthesis, later CO₂ driven global warming and mass extinctions. Anhydrite decomposes at 1200ºC and produces SO₂ gas. A 10 km bolide at Chicxulub might vaporize 300 km³ of sedimentary anhydrite, injecting 400 billion tons of SO₂ into the stratosphere. This SO₂ would deplete the ozone layer and form H₂SO₄ that would backscatter solar radiation, possibly resulting in an 110ºC decrease in global temperature. Sulfuric acid in the atmosphere would also cause acid rain for a short period of 3-4 years.

Supporting evidence for this hypothesis includes shallow carbonate dissolution, oxygen isotopic ratios of marine fauna that indicate cooling, and sea water strontium 86/87 ratios that suggest increased continental weathering. Bruce Horton, Dan Melkman, Doug Rankin, Pete Holman, Kevin Burke, Scott Wing, Gene Robertson, Phil Candela, Ched Druitt, and a redhead in a turquoise shirt asked questions.

Thomas Hoering presented research on the use of methyl-branded hydrocarbons as biomarkers. He investigated whether branched hydrocarbons maintained the 2,3 site branches characteristic of living species or were rearranged during diagenesis. After separating hydrocarbons in the PC Nonsuch Shale using synthetic zeolites and silicalite sieves, mass spectrometry analyses indicated nonequilibrium assemblages consistent with diagenetic alteration, perhaps by acid catalysis on mineral surfaces (including clays that contain acid water). Tom kept his talk to 17.5 minutes so that we would invite him back in another 15 years. Questions by Gene Robertson, J.K Bohlke, Bill Howser, Moro Sato, Dave Freeman, Steve Huebner, E-an Zen, Hal Gluskoter, and Bruce Doe.

The final talk was by Jack Rinker who discussed the Remote Sensing Field Guide used in Operation Desert Storm. Jack gave us tremendous insight into Army intelligence when he reported that 27,000 copies of the manual had to be printed so that 1,000 copies would make it through military channels to the troops in the field. Jack informed us that landscape patterns are unique and readily identifiable, as long as an appropriate scale is available: otherwise braided streams can't be distinguished from diseased bronchial tubes. Jack's mixed media presentation took 28 minutes and he never explained what defilade means. Questions by an unidentified man, E-an Zen, Pete Toulmin, Kathy Krohn, Doug Regan, and Doug Kinney.

The meeting was attended by 115 people, including 13 past presidents; it adjourned at 10:07 pm.

respectfully submitted,

Karen L. Prestegaard

Minutes of the Geological Society of Washington

January 22, 1992

The 1221st meeting of the Geological Society of Washington was called to order at 8:05 pm January 22. One guest, Parchem Curtis, of the Smithsonian Institution, was introduced, three new members were also introduced: we paused to acknowledge new member J.K. Bohlke who was loitering in the back of the room. Judy Ehlen, Dick Tollo, Jane Hammarstrom, Steve Huebner, and Tom Blackburn made announcements.

Greg Sohn presented the news flash is that he has found 2 ostracods in core samples from Lake Baikal that are a different species from the ones found by the Denver Group, increasing known ostracod diversity at Lake Baikal by 100%.

Peter McCabe, presented the hypothesis that organic deposition in mires controls nearby clastic accumulation. Cretaceous coals of S. Utah are found landward of vertically stacked nearshore marine sediments. Organic deposition can keep pace with the generation of accommodation space produced by sea level rise, but shoreline erosion during sea level rise is retarded by the presence of peats. These persistent peats can be compared with reefs which also maintain their position via organic deposition. Modern analogues to the Cretaceous paleo-mires are probably the Indonesian-type raised mires which form in tropical coastal regions that receive daily precipitation. The Mississippi Delta marshes are not good analogues because they receive too much clastic sedimentation (or at least they did before the Army Corps of Engineers got hold of the River). Questions by Steve Huebner, George Helz, Bruce Lipin, Peter Warrick, Scott Wing, Pete Stifel.

James Brennen of the Geophysical labs discussed pathways for diffusive fluxes during metamorphism. Possible pathways include cracks, which are metastable because they need pressurized fluid sources and the equilibrium fluid geometry that is dictated by fluid-mineral contact angles, to which Brennen directed our attention. In quartz-fluid systems, contact angles increase as the CO₂ content of the fluid (CO₂ +water) increases, resulting in fluid beads and discontinuous fluid pathways. Assuming that hot rocks develop their equilibrium fluid geometry quickly and that a unique contact angle exists for known fluid- mineral compositions, effective diffusivity can be calculated given fluid diffusivity, tortuosity and porosity. Brennen's calculated rates of chemical diffusion compared well with experimental results. Questions by Moro Sato, Karen Prestegaard, Steve Huebner, George Helz, and Gene Robertson.

Paul Hearn and Steve Coleman gave a tag team presentation of USSR-US paleoclimate research in Lake Baikal, situated in the Baikal rift zone of Siberia. This high latitude lake has a highly seasonal climate, it was not glaciated, but recorded glacial events. Up to 8 km of undisturbed sediments have been deposited in different environments with varying sedimentation rates. A team of scientists dominated by USGS personnel has been looking at seismic data and short gravity cores from the Selenga Delta (high sed rate) and Academicians' Ridge (low sed rate). Grain size, biogenenic silica, and diatom analyses from the ridge site indicate that the climate changed in the last 50 cm of deposition, , thought to represent the Holocene boundary. More concrete results will be available after radiocarbon, organic geochemistry, carbon isotopes, magnetic susceptibility, sulfur content, phases, and sulfur isotopes studies are completed. Deep sediment cores will hopefully be obtained by drilling from ice platforms in this winter and next; if Russia doesn't go broke first. Questions by Doug Rankin, Moto Sato, Hal Gluskoter, E-an Zen, Kevin Burke, and Patchem Curtis.

President Huebner introduced Steve Coleman after he had given his talk and the society gave Bruce Lipin a standing ovation for his work as program committee chairperson for the past year.

Respectfully submitted,

Karen Prestegaard

GEOLOGICAL SOCIETY OF WASHINGTON

Minutes of the 1222nd meeting

February 12, 1992

The 1222nd meeting of the society was called to order at 8:05 pm by president-elect Phil Bethke. Several guests were introduced: Mike O'Connell, Univ. of Maryland and Raguel Frank of the Smithsonian Institution. Parchem Curtis was introduced as a new member.

The first talk was given by Karen Prestegaard, who discussed whether useful information can be gleaned from time series data of bedload transport data. The time series show long-term persistence that may result from interactions among surface and subsurface particles and cascades of particles. Results indicate that it might take up to 100 minutes to generate a representative bedload sample for heterogeneous streams. Questions by Gene Robertson, Phil Bethke, Mary Hill French, Kevin Burke, E-an Men, Bill Hauser, and Marty Germines. I thank E-an Zen for recording the names of questioners.

Rebecca Carmody, discussed the ¹⁸O-depleted silicic igneous rocks in Iceland. Meteoric water that is depleted in ¹⁸O interacts with rocks at high temperatures during which oxygen exchange occurs, producing lavas that are significantly lower in ¹⁸O than MORBS. Carmody considered whether the Slaufrudalur rhyolite intrusion is an intrusive equivalent of silicic lavas, and showed evidence consistent with that hypothesis. She also suggested that silicic magmas might be recycled within the volcanic system. Questions by Patchem Curtis, Pete Tollman, Moro Sato, and Bevin French.

William Melson introduced us to chugs, wooshes, explosions and other noises recorded at Arenal Volcano in Costa Rica. The seismic records are consistent with records generated by gas ejection rather than flow, the most intense motions are transverse and are similar to a Love wave, but they are not Love waves. The time series of eruption magnitude indicates self-afine behavior with longer intervals between larger events, this might relate to the time required for gas pressures to build up. Melson also indicated that gas emissions can occur independently at several locations creating overlapping chugging centers. Questions by Doug Rankin, Kevin Burke, Gene Robertson, Bill Burton, Bill Howser, Phil Bethke, Dave Freeman, and Pat Shanks.

We adjourned at 9:45, the meeting was attended by 110 people.

Respectfully submitted

Karen L. Prestegaard

GEOLOGICAL SOCIETY OF WASHINGTON

Minutes of the 1223rd meeting

February 1992

Steve Huebner called the meeting to order at 8:10 pm. Donald Hull, Derk Bownan, Ross Engel, Haruice Werner, Tom Nicholson, and Sean Bensonfad were introduced as guests. New members include: Raquel Frenk, Hair Moody, Lisa Campbell, and Cookie Lipin. We held a moment of silence in honor of McKenzie Gordon, Jr, who died around Feb 1. Dick Tollo, chair of the second century committee is looking for ideas; Judy Ehlen announced that there are 5 science fairs on March 21 and April 11 that need Judges.

The first talk was by Judy Denver, USGS, who talked about the effects of agriculture on groundwater chemistry in the Delmarva Peninsula. The permeabilities of various formations influence flow rates and the amount of contamination of the aquifers. Natural water is a NaHCO₃ or a CaHCO₃ water with very dilute concentrations of most species and nitrate concentrations averaging 0.10 mg/l; only 10X of the total wells sampled in the Delmarva Peninsula had these chemical characteristics. Agriculture has changed the water chemistry, producing CaMgNO₃ waters with average nitrate concentrations of 8.2 mE/l. The high Ca and Mg concentrations result from the liming of fields and NO₃ reflects agricultural nitrate in water; sources include chemical fertilizers and chicken excrement. Groundwater ages have been determined using aqueous CFC concentration data. Due to the increase in fertilizer use and burgeoning chicken populations in last 30 years, recent groundwater has higher nitrate concentrations than older groundwater. The slow movement of groundwater means that the full impact of agricultural nitrate on the Chesapeake Bay has not yet occurred: it will take 40 years for high nitrate groundwater to reach Rehoboth Bay. Questions by Dan Milton, Karen Prestegaard, Julian Kimball, Steve Huebner. Jack Griffen, E-an Zen, J.K. Bohlke, and Tom Anderson.

Terry Engelder, of Penn State, treated us to his research on the mechanics of thin thrust sheets. In 1959, Hubert and Rubey suggested that thin thrust sheets can move over long distances if the effective normal stress along the fault plane is reduced by high pore pressures. Engelder suggested that high pore pressures must evolve prior to mechanical compaction or tectonic deformation. Engelder investigated whether gases produced in situ from organic-rich black shales leave the shales and generate the high pore pressures required. Supporting evidence for this hypothesis included: (1) concentration of Joints in shale beds and an increase in the number of Joints with depth, (2) methane in fluid inclusions in the shales, (3 Pressure-temperature constraints for methane genesis that are consistent with the 6 km overburden pressure of the stratigraphic column (4) An elegant analysis of Joint propagation in the shales. Questions by Moto Sato, James Brenan, E-an Zen, Steve Huebner, and Brooks Hanson.

Sorena Sorensen discussed aqua tectonics in Sierra Nevada roof pendants. Sorena showed isotopic and other data that indicate the various that sea water mixes with a growing pile of volcanic rocks. Isotopic ratios do not indicate the presence of significant amounts of meteoric water. Sorena suggests that the isotopic signature of individual formations evolved early and they stewed in their own juices. Water/rock ratios were relatively low: 100:1. Questions by James Brenan, E-an Zen, Steve Huebner, Doug Rankin, and Bill Burns.

We adjourned at 9:50, the meeting was attended by 68 people.

Respectfully submitted.

Geological Society of Washington

Minutes of the 1224th meeting

March 11, 1992

The meeting was called to order at 8:07 by President Huebner. In honor of the large attendance (150 people) Jeff Grossman gave an informal communication on the history of meetings that set attendance records. In his analysis, people show up for hot topics, hot dates, and big shots. He also noted that the effectiveness of disasters as a drawing card has diminished over time. Questions by Liz Koozman and Tom Bullo.

Frank Press was the first and only speaker of the evening. He provided data for Jeff by giving a presentation on geologic hazards, defined as atmospheric, geologic and hydrologic processes that effect human lives. Loss of life from natural hazards are not distributed equally around the globe, which is a consequence of both geologic distribution of processes and the preparedness of the populace for the events. Due to population stresses in hazard-prone areas, loss of life is not decreasing even though our understanding of these events is increasing. The U.N has recently recognized of the role of human behavior in determining whether natural hazards become human disasters and designated the 1990's the "Decade of Natural Hazard Mitigation"; In the U.S. has Marilyn Quayle has chosen to work on the problem while her husband worries about those canals on Mars.

There recently have been major successes in the U.S., Japan and other developed countries at reducing the death toll of major eruptions, floods, hurricanes, etc. For example, the eruption of Mr. St. Helens, Hurricane Hugo, and The Loma Prieta earthquake all resulted in less than 50 deaths, while similar types of events elsewhere (e.g., Floods in Bangladesh or earthquakes in Armenia resulted in much greater loss of life). Dr. Press argued that better prediction, preparation, and timely response to those natural hazards could minimize the impacts of these events everywhere if governments were willing to create the framework for the science and sociology of hazard reduction; which clearly require an educated populace. Questions by E-an Zen, Bill Barton, Dallas Peck, Ann Door, Karen Prestegaard, Dennis Krohn, Dave Zeno, and Bill Melson.

Geological Society of Washington

Minutes of the 1225th meeting

March 25, 1992

The meeting was called to order at 8:05 pm by President Huebner. Gautem Sen was introduced as a guest; Fred Simon mentioned that the second and final dues notice had been sent--pay up!

Robin Brett presented an informal communication on research he had conducted on evidence for a K-T boundary impact in Cuba. His conclusion was that there is no evidence of a K-T boundary impact, he found more normal explanations for must features, including volcanic features and spheroidal weathering which may have been interpreted as boulder beds. Questions by Gene Robertson and Gautem Sen.

Bruce Doe was our first speaker; he examined the Washington, D.C. temperature record for evidence of CO2-induced warming. Using Arrhenius' 1896 predictions on the effects of CO₂ warming, Doe looked for warming, decreases in the daily temperature range, and changes in the frequencies of occurrence of record high and low temperatures. Doe found that the heat island effect is not obvious, and that changes consistent with CO₂ warming are most common in the 1980's and 90's. These changes include a decrease in the average daily temperature range, a decrease in the number of record lows decreased over time while the number of record highs increased. 1988, which was a cooler than average year had a significant number of record high temperatures in the summer. The result: there is evidence for greenhouse warming, maybe. Questions by Calvin Ross, Tren Hazelton, and Tom Blackburn.

Marty Giaramita discussed deep-seated fluids in eclogite facies of subduction zones represented by samples from the Franciscan Complex and the Samana Peninsula in the Caribbean (Marty quickly explained that he used samples from the Smithsonian Collection and that he didn't actually go there). The fluids in question are derived from dehydration of the subducted slabs. Marty examined fluid inclusions entrapped in clinopyroxenes, many of which were considered to be primary. The fluid composition was relatively homogeneous, and primarily water with low salinities, these results are quite different from those reported by Philippot and Selverstone who found compositional heterogeneities on a the order of mm. Questions by Gautem Sen, George Helz, J.K. Bohlke, Robin Brett, Gene Robertson, and I-ming Chou.

Andy Shen presented his diamond anvil hydrothermal studies. Advantages of the diamond anvil are the wide range of temperature and pressure conditions that be obtained with a relatively safe (i.e. non-exploding) and inexpensive technique. Direct observations of the materials can be made using in situ spectroscopic methods. Temperatures could be measured directly, the pressures were harder to characterize. Methods included using the equation of share of NaCl, gold, argon, fluorescent wave shifts of ruby, and the equation of state of water which could be calibrated using the a/b quartz transition. Andy showed some neat videotapes of the quartz transitions, we left the talk wondering whose representation of the equation of state of water is really correct. Question by George Helz.

Respectfully submitted

Karen Prestegaard

Geological Society of Washington

Minutes of the 1226th meeting

President Huebner called the meeting to order at 8:05. The following guests were introduced: Anne Kuhler, Kin Casely, Alex Van Oss, Anne Lin, Ray Willehman, Sheridan Mageed, Luis Cartea, and Joseph Biggs. We recognized new members Greg Bluth, Virginia Bluth, Edith Krohn, Charles Tranter, Frank Press, and Alex Van Oss. President Huebner announced the nominating committee for officers of the society. Committee members include Dick Fiske, Doug Rankin, Tom Stern, Joe Boyd, and Phil Candela. Chair of the committee Dick Fiske requested that people with candidates for officer positions to please put names forward to any member of the committee. E-an Zen questioned the lack of women on the nominating committee. Fiske mentioned that this might preclude qualified women candidates from being nominated; secretary Prestegaard noted to herself that 23 women were in attendance at the meeting.

Cy Galvin began the meeting with an informal communication on Volume III of Lyells' Principles of Geology, which is being issued as a facsimile edition by University of Chicago Press. He noted that the Cretaceous-Boundary was established on evidence from field work conducted around London and Paris where the K-T boundary was prominent. Placement of the boundary at another stratigraphic position may have precluded the development of iridium studies of the K-T boundary and the asteroid impact hypotheses for dinosaur extinction. Questions by Dan Milton and Bill Burton.

Peter Olson presented his theory of the possible relationship between mantle plumes associated with hot spots and magnetic polarity reversals. Although the volume of lava produced by hotspots in the oceans is small, related phenomena of flood basalts and oceanic plateaus create much larger volumes of magma. Many of these oceanic plateaus are Cretaceous in age, produced perhaps by a massive plume event. The Cretaceous is also the time of the normal polarity Superchron. Olson suggested that mantle plume formation steepens the temperature gradient and that the increased energy of the core dynamo results in a super chron with no reversals. Questions by Dan Milton, Kevin Burke, E-an Zen, Bill Burton, and Gene Robertson.

Our next speaker, Dave Freeman, defined porphyrins, which are residues of chlorophyll, and explained that they can be used as biomarkers and thermal markers in sedimentary rocks. Freeman concentrated on the relationship between porphyrin structure and temperature. Porphyrins with exocyclic rings lose the rings at high temperatures resulting in spare structures that loses its fingers and toes with higher temperatures. This change in structure with temperature affects the adsorbed wavelengths of the molecule; which may provide a simpler identification technique than separating and structural identification of porphyrins. These structural changes in porphyrins may be an aid in determining the thermal history of strata relative to the oil window. Questions by Kevin Burke, E-an Zen, Dan Milton.

Tom Muir discussed wetland definitions, functions, and policy. Muir presented estimated amounts of wetland loss from different ecosystems in the period from 1950's to the mid 1970's and provided information on wetland values for flood control, wildlife habitat, and water quality. Currently, wetlands are regulated by section 404 of the clean water act. The various agencies that regulate wetlands came up with a common definition in 1988. The Bush administration proposed a different policy for defining wetlands in the fall of 1991; this proposal is still under debate. Most non-tidal wetlands are on private lands. Questions by Mack Ross, Moto Sato, Cy Galvin, and Karen Prestegaard. The meeting was attended by 67 people

Respectfully submitted

Geological Society of Washington

1227th meeting

April 22, 1992

The meeting was called to order at 8:02 pm by president Huebner. Guests: Becky Crow, Vladimir Lipin, Marcus Milly, Andre Dimhers, Don Swanson, Alan Leaventon, Mr. Aldrich, Erwin Morin, Donna Cohen, and Tyler Copland were introduced. Mike O'Connell was introduced as a new member.

We had several short communications: Gene Robertson of the Centennial Committee gave the educational backgrounds of some of the founders of the Geological Society of Washington. Bruce Wardlaw explained how he survived a run-in with bandits during a recent field season in Pakistan. Dan Milton pursued to origin of the terms outcrop and strike, both of which date from the early 1800's.

The first formal presentation was by Michael Ryan of the USGS. He presented evidence for the theory that magma rises to a horizon of neutral buoyancy where it spreads laterally. Field support for the idea comes from in-situ sonic logging and microseimicity. Questions by Bill Burton, Dick Fiske, Pat Shanks, Dave Stewart, E- an Zen.

Lucy Edwards, USGS, gave a paleontologist's view of aquifers near the Savannah River site. The research team wants to determine whether groundwater flows from South Carolina across the Savannah river to Georgia. Questions by Meyer Rubin, Marcus Milling, Karen Prestegaard, Dave Freeman, and Tyler Copeland.

Neil Sturchio, of Argonne National labs, carried on a bit long for the last talk of the spring. He discussed compared travertine age dates with the glacial stratigraphy, providing better age constraint for the Pinedale glaciation. Questions by Peter Stifel, E-an Zen, Tyler Copeland, Raymond Rye, and Pat Shanks.

95 people attended, we adjourned at 9:50

Respectfully submitted

Karen Prestegaard

Geological Society of Washington

Minutes of the 1228th Meeting

September 23, 1992

President Huebner called the meeting to order at 8:05 pm. Woody Henry, Bob Ilchick, Klaus Metzger, Bao Tang Liu were introduced as visitors, New members Marcus Milly and Becky Crowe were also introduced. We had moments of silence in remembrance of Annabelle Olson, Tom Nolan, Bill Greenwood, Phil Build, and Edward P. Henderson. Bill Burton announced the fall field trip, Gene Robertson announced 100th anniversary presentations.

The first talk was by Phil Piccoli, a Ph.D. candidate at the University of Maryland who noted all of his committee members in the audience and kept his talk to under 17 minutes. Phil discussed trace element distribution in titanites in the Tuolumne granitic complex; distributions that he though originated from an influx of basic magma into the system during crystallization. Questions by Jane Hammarstrom, Dan Milton, Moto Sato, Mike Brown, Gene Robertson, E-an Zen, and Craig Schiffries.

Rachel Burks of Towson State Univ. discussed field evidence for motion on the Beaverhead fault zone in SE New England. Although the field exposures leave considerable room for interpretation, she presented data supporting her hypothesis for multiple anastomosing faults in the BFZ. Questions by Moto Sato, and unidentified Maryland student, Bill Burton, and E-an Zen.

The final talk was by Holly Stein who is working on a Re-Os study of climax type molybdenum deposits along with John Morgan and Mary Horan. Holly discussed Re-Os systematics, the geology of Mt. Evans, and some preliminary results of Re-Os isotopic data from molybdenite and galena at Mt. Emmons, some of which suggest Miocene ages for mineralization. Questions by J.K. Bohlke and Steve Shirey. Holly carried a big stick for much of her talk intimidating the secretary into letting her run over time.

Seventy-six people attended the meetings. We adjorned at 10:13

Respectfully submitted

Karen L. Prestegaard

MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON

1229th Meeting

[Minutes missing]

Minutes of the Geological Society of Washington

November 4, 1992

The 1230th meeting of the Geological Society of Washington was called to order at 8:04 pm by president Huebner. Hazel Chapman of the Cambridge Univ. was announced as a guest. We welcomed Elisabeth Widom and Jody Bourgeois as new members. We spent some time discussing the Helz amendment for representative democracy for dues increases. President Huebner begged indifferent members to get involved with the Washington Academy of Sciences and their educational programs.

Cy Galvin presented an informal communication on his recent visit to Venice.

The first speaker was Chris Neuzil who discussed flow in tight rocks, particularly the Pierre Shale in South Dakota. Neuzil showed measured head distributions in the Pierre shale which suggest that flow is upwards from the bottom of the unit and down from the top and no flow out from the center of the unit, which makes it a candidate for contaminant repositories. The pressure distribution in the shale could result from the 200-300 m of erosion since the development of the flow system (10,000 to 1 million years ago). Questions by Dave Stewart, Mike Rotan, George Helz, E-an Zen, Sorena Sorensen, Dan Milton, and Craig Schiffries.

John Ferry also discussed flow in low porosity materials, but in his case he calculated fluid fluxes during metamorphism by examining the progress of chemical reactions. Ferry examined reaction progress in 5 metamorphic zones through which flow was assumed to be largely horizontal until it was heated, rose, and exited from the system in the center of the complex; a region riddled with quartz veins. Questions by Moto Sato, George Helz, Bill Burton, Dave Stewart, Gene Robertson, and J.K. Bohlke

Our final speaker was Eric Barron who addressed the role of global oceanic circulation and climate. Barron suggested that we can learn about the role of the ocean in our present climate by studying episodes in Earth's history when the climate was much different than the present. The late Paleocene was a time when the poles were warmer than present and the equatorial regions were cooler. This reduction in the latitudinal temperature gradient would serve to weaken global winds, making it difficult to heat the centers of continents. There is no evidence for cold Paleocene continental interiors, which suggests that the Paleocene ocean was playing a 10-15% greater role in heat transport than the present ocean. This difference can be explained by the differences in continental geometry. Questions by Dave Stewart, Bill Burton, George Helz, E-an Zen, Sandra Neuzil, Karen Prestegaard, and John Tracey.

We adjourned at 10:07; 65 people attended.

Respectfully submitted:

Karen Prestegaard

Geological Society of Washington Minutes of the 1231st Meeting

November 18, 1992

President Huebner called the meeting to order at 8:04 pm.

Guests were: Tom Thorasen, Don Avery, Ralph Wagner, Bill Boyl, and Steven Bartolo. New members Carol Russell, Beatrice Bidwell, Fred Spilhaus, and MaryEllen Cameron were introduced. We heard a report from the committee charged with removing gender bias from the society's by-laws. Although the proposed changes are rather simple, several members registered their dislike for the substitution of "chair for chairman". We tabled the topic of chair until the next meeting. The Helz amendment for taxation with representation by council was presented again.

Tom Wright of HVO gave an overview of the past 10 years of the current eruption of Kilauea. The eruption represents a large volume of remarkably homogeneous magma. Questions by John Slack, Pete Toulmin, and Jonathan Fink.

Beginning at 8:49 we heard from Grace Brush, who discussed temporal variations in sedimentation rates in the Chesapeake Bay.

Grace used pollen concentrations to determine sedimentation rates, which are highly variable in most core intervals. Prior to European colonization, major peaks in Bay sedimentation rates are related to fires, recorded in the cores as charcoal layers. The medieval warm period shows up as a period of high charcoal concentrations and sedimentation rates that are as high as modern rates. Questions by Carol Russell, Cy Galvin, Dick Fiske, Brooks, Hansen, Pete Toulmin, and George Sellars.

Jonathan Fink, currently at NSF examined whether silicic dome- forming stages of volcanic complexes are relatively safe. The recent eruption of Unzen and the deaths of Katya and Maurice Kraft and Harry Glicken illustrate that rhyolitic dome-building eruptions can turn catastrophic. Jonathan showed results of mapping of several rhyolitic flows that suggest a water-rich layer can be trapped in the flow interior by a an obsidian cap. Release of volatiles can form explosion pits on the flow surface or can result in more catastrophic explosions. Questions by Moro Sato, Bob Ilchick, Carmela Carzione, George Helz, Phil Candela, Henrick Van Oss, and Pete Toulmin.

Our last speaker of the evening was Edward Young of the Geophysical Lab who used oxygen isotopic composition of mineral grains to map fluid flow during metamorphism in a garnet-muscovite- chlorite rock. Oxygen isotopic composition variations in garnet suggest adsorption and regrowth during metamorphism in a short period (less than 10,000 years). Young suggests that garnet regrowth involves a dehydration reaction. Questions by Jane Hammarstrom, Joe Boyd, and Bill Burton.

I want to convey my thanks to J.K. Bohlke for putting together a diverse and interesting program in 1992.

Respectfully submitted,

Karen Prestegaard

MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON

1232nd Meeting

[minutes missing]

GEOLOGICAL SOCIETY OF WASHINGTON

Minutes of the 100th Annual Meeting

December 9, 1992

President Steve Huebner convened the 100th annual meeting at 9:20 p.m. The 62 members of the audience were subjected to a trilogy of reports delivered by Jane Hammarstrom who read the minutes of the previous annual meeting as well as Karen Prestegaard's Annual report of the Meetings Secretary, and her own report of the Council Secretary. President Huebner gave the Treasurers report for Fred Simon, noting that the Society's finances were in better balance than they had been the previous year due to the much ado'd dues increase of 1992. Let the annals of the Society note that the absence of key Council members at the annual meeting reflected conflicts with the fall AGU meeting rather than absence due to overindulgence at the preceding beer break.

George Helz reported that the October 16th audit showed the books to be in good order. Dave Stewart, ever mindful of the proper way to do things, moved to accept the four previous re- ports. Kathy Krohn presented the Membership Committee report. Kathy noted that the Society rolls showed 652 member in good standing, i.e., dues payers. This included 476 regular members, 163 corresponding members, 16 students members, and 7 "something elses" that the secretary failed to record because she was still trying to recover from the facial expressions of the audience when Kathy mentioned something - no one is sure exactly what about hygiene issues.

Moving along to Public Service, Judy Ehlen reported that we judged 11 science fairs, participated in a science fair workshop and a field trip for teachers. Lori Hollidge was the 1992 recipient of the science fair grand prize. In what may have been an obscure and poorly conceived 11th hour attempt for waking Sleeping Bears, Bruce Doe asked if the teachers had seen the horizontal pot holes on their trip to Great Falls.

Gene Robertson reported on Centennial activities. E-an Zen presided over the best paper awards. Jeff Grossman received the Great Dane award for his well-illustrated informal communication on factors that aroused audience interest and boosted attendance over the years based on his analysis of Society archives.

Terry Engelder and Chris Neuzil tied for second-best paper in two separate talks on shales. Terry spoke on "Distribution of gas-driven joints within Devonian shales of the Appalachian plateau" in February and in November, Chris presented "Groundwater hydrodynamics of an ultra-low permeability shale, South Dakota". In a first-time family sweep, the 1992 Best Paper Award went to another Neuzil - Sandra - for her October 14th talk on "Indonesian peat: modern analog for some coal" in which she compared the quality, paleography, and regional distribution of Appalachian coals to Pleistocene and Holocene peat growth in Indonesia as a model for understanding Appalachian coals. J.K. Bohlke was commended for the high quality of the 1992 program.

Dan Milton emerged as the undercover ursine to present the Sleeping Bear award to Jingle Ruppert for her spontaneous retort during the linguistic wars of 1992. Jingle's proposal to replace the word "chairman" in Society by-laws with the gender-neutral word "chair" prompted Zen to declare that the only acceptable definition of chair is "a piece of furniture" Toulmin chimed in with "chairman means head" and Jingle won by getting in the last word in this vaudevillian exchange with "a head is a toilet"

President Huebner read the slate of officers for 1993 and Dave Stewart moved that nominations be closed. The slate was unanimously accepted by the members, the gavel passed and new President Phil Bethke adjourned the meeting at 10:18.

Respectfully submitted,

Jane Hammarstrom (for Meetings Secretary Karen Prestergaard)