GSW: 1981 MEETING MINUTES

 

GEOLOGICAL SOCIETY OF WASHINGTON

14 January 1981

     The 1074th meeting of the Society was held in the John Wesley Powell Auditorium on the 14th of January, 1981. The meeting was called to order by President Doug Rankin at 8:02 p.m. The min­utes of the previous meeting were read and corrected. The deaths of two members of the Society were announced.

     The names of new members were not announced, as the names (not the members) were locked in the trunk of a car. There were four visitors. Carl Thornberg announced the field trip to view the coral reef at the Smithsonian. In addition, he suggested that anyone involved in field-related research in the Washington area to get in touch with him, so as to arrange possibly a field trip. Phillip Justice of the NRC announced a lecture on 26th January, at NRC in Bethesda. Third, the Paleontological Society was to meet 21st of January at the Museum of Natural History.

     The scientific program was concerned with plate tectonics in New England and was presented on various geological and geographical scales. Alfred Weggoner, as he floated on the Arctic ice packs, would never have dreamed that plate tectonics would have reached this level of complexity. Maybe because, as Rankin noted "what would plate tectonics be without color?," the ice packs were white.

     Bill Leo presented a paper on "Trondhjemites associated with Oliv­erian domes, western New Hampshire and central Massachusetts." He presented petrological evidence for the theory that trondhjemites are chemically and stratigraphically similar to island arcs. Questions by Ratcliffe, Towe, Foose, and Justice. Next, Nicholas Ratcliffe gave us "Some thoughts on problems in dating the Taconic orogeny in western New England." When his slides were positioned correctly, he presented a tapestry of "nested slices", "root zones", and the "soles" of various tectonic plates. The complex geology of western New England does not fit a simple model, but has evolved in multiple stages including the collision of ocean basins. Questions by Palmer and Leo; comments by Zen.

     The final talk was by Peter Robinson, who gave a big, broad picture of New England tectonics in his talk, "Plate tectonics and the Acadian orogeny of southern New England". Color and palm trees, indicative of plate tectonism and island arcs respectively, were used to demonstrate a three stage model for the geology of the area; 1) the nappe stage, 2) the back folding stage, and 3) the dome stage. Questions by Estep, Rankin, Zen, Rumble, and Lonker.

     The meeting was adjourned at 10:04 p.m. NO questioners were left unidentified. The attendance was 94.

     Respectfully submitted,

     Marilyn Estep, Secretary

 

GEOLOGICAL SOCIETY OF WASHINGTON

28 January 1981

     The 1075th meeting of the Society was held as usual in the John Wesley Powell Auditorium on the 28th of January 1981. At 8:06 p.m. the meeting was called to order by the 2nd Vice President Ken Towe, who had figured that his title came without responsibility, that is until that evening. The minutes were approved as read. Four new members, Peter Beck, Emi Ito, Harry Smedes, and Dorian Nicol, were elected to the Society. Five visitors, notably soil scientists from the area, were introduced.

     Bickford and Van Schmus discussed informally their progress on the study of Precambrian geology of the mid-continent basement. Second, Antonio Segovia, Univ. Md., announced his involvement with "young things" in the Deep South. He presented radiocarbon dates for organic matter in fluvial deposits. One question was asked of each speaker.

     The formal communications began with Erich Dimroth, who spoke on the comparison between Cenozoic and Archean pillow lavas as indicators of diagenetic redox reactions, sea-floor metamorphism, and the Precambrian atmosphere. He concluded that there was appreciable free oxygen in the atmosphere 2.7 billion years ago at a level approximately one order of magnitude lower than at the present time. There were questions by Vanig, Hearn, and Sheldon; and one comment by Melson. Towe asked three pointed questions.

     The second talk was concerned, again with "young things", that is, soil and weathering profiles from a locality in New Jersey which was pro­posed to be 8-10 million years old, and another locality on the Eastern Shore, which was proposed to be 200,000 years old. Helaine Markevich described the two areas and included a somewhat maligning comment on the olfactory and scenic grandeur of the state of New Jersey. Milan Davich, then presented chemical evidence demonstrating the in situ diagenesis of soils: 1) X-ray data are continuous and progressive; 2) the addition of new material to the soil was not indicated; and 3) the changes seen in soil profiles are mediated by mineral stabilities. There were questions by Robertson, Adenoff, Vanig (2), Towe, Jones (2 and 1 comment), Milton, and Foss (2).

     The meeting was attended by 64 persons and was adjourned at 9:46 p.m.

     Respectfully submitted.

     Marilyn F. Estep, Meetings Secretary

 

GEOLOGICAL SOCIETY OF WASHINGTON

11 February 1981

     The 1076th meeting of the Society was held on the 11th of February 1981, at the John Wesley Powell Auditorium. The meeting was called to order at 8:04 p.m. by President Rankin. The minutes were read and corrected. Eighteen new members were elected to the Society. There was one visitor.

     The field trip to view the coral reef exhibit at the Smithsonian was a resounding success. If you were unable to attend the previous trip, there is a possibility that a second trip will be organized.

     Jim O'Connor of the USGS presented a series of bizarre slides con­cerned with the collapse of a salt dome in Louisiana. Fourteen million ft3 of lake water drained into the dome whereby creating a crater 1500 ft across: Questions by Rankin, Roedder, French, and a comment by Toulmin.

     The first formal presentation of the evening was by H. William Menard of the USGS in Reston, Va. With appropriate intricate arm motions, Menard hulaed his way through a discourse on the upward and downward motions of the earth's crust during tectonic events. The width of island shelves increases and the lithosphere is thicker with increasing age. Exceptions occur when plates encounter swells, and they warp.  Questions were asked by Shlepshevsky, Hewitt, Helz, Segovia, Tracey, Robertson, Doan, and Milton.

     Philip Brown, an NSF Fellow also at the USGS, then delivered a substantive lecture on tungsten skarn formation at Pine Creek in the Sierra Nevada of California. The ore deposit containing Ca-tunstate and molybdenite was formed at pressures of approx. 1½ kb and 500-600°C. The metals were conducted to the locality via contact veins mostly likely from massive sulfide deposits. Sable carbon and oxygen isotope ratios were used to demonstrate large amounts of fluid flow that occurred during metamorphism. Questions by Chang, Peck, Eugene Robertson, Leo, Doan, and Ralph Robertson.

     The final presentation was by George Rossman from Cal Tech, who deliv­ered an entertaining discussion on the irradiation of less precious gems to create more precious gems or in essence, "how to spin flax into gold." In nature, radioactive uranium decay excites electrons in min­erals, which causes oxidations and. reductions of metal ions and thus color changes. The value of certain minerals as gems is strangly [sic] depen­dent on color, and these colors in gems can now be artificially and in­expensively reproduced. Helz (2), Roedder, Rankin, Lopez, Morgan, French, and Estep asked questions.

     The meeting was adjourned at 9:45 p.m. and was attended by 104 people.

     Repectively submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

25 February 1981

     The 1077th meeting of the Society was called to order in the John Wesley Powell Auditorium at 8:04 p.m. by President Rankin. The minutes were read and corrected. There were two visitors present.

     The first formal communication was by Charles Warren of the USGS, Reston, on the defrosting of the Berkshires. By mapping the positions of ice dams and end points, glacial grooves, and flow directions, Warren was able to correlate the drainage areas of the Connecticut and Hudson River valleys at the various phases of deglaciation. This year Warren's calculation of an estimate of the year in which the defrosting began was 11,530 BC.  Questions by Tracey, Zen (2), Rankin, and Schaeffer.

     Thomas Gibson, just in from Jimmy Carter's fish pond in Georgia, discussed facies and sea level changes in Paleogene strata of the eastern Gulf Coast. The area lends itself to study because of the presence of a 500 ft relief, good lithologic units, and distinct beds of red rocks. Those with color blindness were urged to work elsewhere. In addition, by determining the percent of planktonic vs. benthic species found in the rocks, the depth of the sea in this area could be calculated. Tectonic activity was controlling sea level changes even in a passive margin. Questions by Tracey (2), Hewitt, Menard, Towe (3), Zen, Hayes, Finkelstein, and Repetsky.

     The last communication of the evening was by Antonio Segovia of the Univ. of Maryland. While swilling beer and shuffling computer printouts over the podium, Segovia attempted to bring back respectability to the closet concept of regmites, which are numerous fractures or linear features that have not been properly certified in the field. Regmites are believed by Segovia to be fractures through the crust occurring at crustal block boundaries and indicative of episodic activity in the motion of blocks vs. plates away from ridges. After resounding applause by Univ. of Md. students and others, Segovia was questioned by Rankin, Duchl, Lopez, Robertson, and Menard.

     The meeting was adjourned at 10:04 p.m. and was attended by 71 people. Beer money: since the 1st of January, $64.85 was collected from four meetings. 333 people attended the meetings and donated an average of $0.195/person. Accounting for the facts that approx. 1/3 of the attendees do not partake in refreshments and half of those who do are destitute graduate students, the figure of cents collected/person is 58.

     Respectfully submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

11 March 1980

     The 1078th meeting of the Society was called to order at 8:06 p.m. by President Doug Rankin at the John Wesley Powell Auditorium. The minutes were actually approved as read. There were 9 new members and no visitors. A special meeting sponsored by the Society and the AAPG will be held at 8:00 p.m. on April 2 at the Carmichael Auditorium in the U.S. American History Museum. Notices have been mailed to all members.

     The first speaker of the evening was that veritable Lion of Limericks, the Guru of Geopoetry, David R. Wones, of VPI, who spoke on the tectonics of Eastern Maine. The plutons in Maine were formed at roughly the same period of time in the Devonian. The geochemical and isotopic compositions of these igneous intrusions varies such that Wones believes the NW plutons, such as Mt. Katahdin, were of a marine, geosynclinal origin. The coastal plutons originated from a mixture of oceanic basalts and mantle material. A major tectonic suture, Wones explained, possibly the Taconian deformation, occurs between the NW plutons and the coastal intrusions. The presentation was punctuated by a limerick. Questions by Lewis (2), Pavlides, Hatch, Rankin, Toulmin, Luddington, and a comment by Leo.

     The Proterozoic development of the midcontinent region is speculative as the rocks are largely covered by cornfields and cow manure. Randy Van Schmus of the University of Kansas has obtained drill cores from oil and gas wells and has succeeded in beginning to patch together the geological patterns of the Precambrian basement in this area. U-Pb dating of zircons shows that the Kansas basement consists of a pocket of 1.37 billion year old rocks, and in general, older rocks occur to the west of Kansas and younger rocks to the east. Continental accretion occurred in this area; however, there is not enough detail for delineating tectonic zones. Questions by Leo, Wones, and Luddington.

     The final presentation was by Clark Burchfiel of MIT, who described an Andean-type margin of Mesozoic California. A cursory view of the stratigraphy of the Eastern Ardilleran thrust belt shows older thrusts occurring to the west and younger thrusts, to the east. In detail, Burchfiel has discovered an irregular occurrence of high angle and vertical thrusts, which may be indicative of brittle and cracked continental plates near a subduction boundary. Questions by Peck, Wones, Fisk (3), Jones, and Segovia.

     The meeting was adjourned at approx. 10:00 p.m., and 98 people attended.

     Respectfully submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

25 March 1981

     The 1079th meeting of the Society was called to order at 8:08 p.m. by President Doug Rankin at the John Wesley Powell Auditorium. The minutes were read and subjected to minor corrections. There were no new members, and four visitors, namely the Skinners from Conn. Carl Thornberg, Chairman of the Public Service Committee, announced that a field trip to W-central Virginia is to be held on Saturday, April 25th. Eric Force of the USGS will lead a group to observe nelsonites, blue-quartz, and any other rocks in the area. The cost will be $10.00.  Then, President Rankin pressed the membership to volunteer to present informal communications of items of immediate or even nonimmediate interest or noninterest to the group. Do not be shy.

     Norman Hatch of the USGS presented the first talk of the evening on the structural history of, specifically, the Pre-Silurian Goshen dome in the Connecticut Valley and the surrounding country rocks. The formations were described by Hatch as a crumpled Devonian rug on a Pre-Silurian floor, or a refolded recumbent fold. By studying the graded beds and by extensive mapping, Hatch described the detailed folding processes. Questions were asked by French, Robertson, Pavlides, Rankin, Zen, and Neuman.

     There have been no nepheline normative rocks found in Tahiti, yet Robert Tracy of Yale University stated his case for calling certain ultra-mafic xenoliths, basanites. The chemical compositions of the xenoliths indicate that they originated from oceanic alkali basalts approx. 1-0.4 my ago. High MgO contents of natural samples and the results of laboratory experiments were reasons for Tracy to suggest the xenoliths were chunks of primitive, unfractionated magma that had escaped unscathed from their parental magma chamber. Questions were asked by French, Menard, Harris (3), Peck (2), Rankin, Boyd, Roedder, Zen, and Morgan.

     The final event of the evening was presented by Nicholas Hotton, a warm- blooded, bipedal, predatory mammal weighing approx 70 kg, from the US National Museum. Hotton discussed the possibilities and probabilities that dinosaurs were warm-blooded and cited vascularized bone structure, pendular motion of the legs, and the predator/prey relationships as part of the evidence for warm-bloodedness. In addition, Hotton compared dinosaurs with mammals, knowing it was a poor comparison, yet stated he did not want to hear about it, as this was "the only wheel in town". Cold-blooded animals are slower to use heat, and the unusually large dinosaurs if cold-blooded should have had problems of heat dissipation.  Hewitt, Thornberg(2), Levy, Menard, and Whitmore asked questions.

     The meeting was adjourned at a rather late 10:19 p. m. and was attended by 94 people.

     Respectfully submitted,

     Marilyn F. Estep,  Meetings Secretary

 

Geological Society of Washington

8 April 1981

     The 1080th meeting of the Society was called to order by a standin President, the 1st Vice President Pete Toulmin, at 8:05 p. m. The minutes were read and approved. There were 3 visitors, including Dr. Cook from Ohio State Univ., a former hostage, now working at the State Dept. Those interested in attending the spring field trip on the 25th of April were urged to sign up.

     In the first presentation, Roy Bailey spoke on the volcanic hazards program of the USGS. After describing the geologic developments of Mt. St. Helens before and during the eruption on May 18th, he then looked into his mega-crystal ball and with the aid of numerous phase diagrams of the compositions of the lavas from the Cascade volcanoes, predicted volcanic activity to occur next at Mt. Shasta, which could become the next Crater Lake. In addition, a large lump of basalt lurks in the Rio Grande Rift System of New Mexico, waiting to destroy the chili pepper crops. The Hazards program developed by the Survey includes volcanic monitoring, hazard mapping, and fundamental research, the latter being at the base of a pyramid of information with Congress at its pinnacle enacting legislation. Unfortunately, the funding pyramid for this program was inverse to the one mentioned above. Questions were asked by Boyd (2); Appleman (2); Sheldon (2); Segovia; Repetsky; Roedder; Towe (2); Simkin; and Robertson, whereas Tilling commented.

     Did the dinosaurs become extinct as the result of a great catastrophe such as dust clouds arising from a meteorite collision or cyanide poisoning from a comet passing through the Earth's atmosphere? Leo Hickey of the USNM presented paleobotanical evidence demonstrating the numerous plant extinctions at the Cretaceous/Tertiary boundary, which may have occurred as a result of the above catastrophes, occurred 50,000-90,000 yrs after dinosaurs themselves became extinct. Hickey described 2 major pollen provinces: one in NE America and Europe and the other in W America and Siberia. In the latter, there is evidence of the most drastic plant extinctions. Diversity of plant species decreased in the North, indicating a drop in atmospheric temperatures, and Hickey believed dinosaurs became extinct due in part to climatic cooling. Questions were asked by Sato, Appleman (3), Davis, Wright, Luddington, Cook, and Outerbridge.

     In the final presentation, John Sutter of the USGS in Reston described the Montagua fault in Guatemala as what he believed to be the collision of the North American plate with that of South America. Sutter delivered a meticulous and clear, yet lengthy, description of K/Ar dating, and used this technique to determine when the minerals in the fault zone were formed and to determine the dates when these minerals migrated to the area. Bits of subducted seafloor that were 237 my old were detected in the fault zone, which was the result of a tectonic event approx 67 my ago. Questions were asked by Segovia (2) and Muller commented.

     The meeting was attended by a crowd of 128 people and was adjourned at 10:08 p. m.

     Respectfully submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

22 April 1981

     The 1081th meeting of the Society was called to order by the 1st Vice President Priestly Toulmin, at 8:05 p. m. The minutes were read and approved. There were four visitors.

     The first presentation was by Emi Ito of DTM who delivered a complex analysis of the alteration of oceanic crust as a function of time, temperature, and fluid/rock interactions. The petrography of rocks collected from the Cayman Rise always showed evidence of deformation and hence, alteration. Using oxygen and hydrogen isotope analyses of mineral separates, Ito demonstrated that a higher proportion of seawater reacts with gabbros to form amphiboles at shallow depths and lower temperatures, whereas less water reacts with rocks of the deeper sections that are at higher temperatures. Questions were asked by Barton and Chayes.

     Michael Engel of the Geophysical Lab then discussed the significance of amino acids and hydrocarbons detected in the 3.8 billion year old Isua rocks, or in essence, did bats excrete guano in the Precambrian? After careful extraction of the Isua rocks by ultra-clean methods and detailed analysis of the extracted amino acids by chemical ionization mass spectrometry, Engel then concluded that the D-L ratios of amino acids indicated a much more recent age for the organic matter than the Precambrian. In fact, the amino acids in the rocks and those of extant lichens growing on the rocks were remarkably similar. Engel concluded with the aid of temperature simulation experiments that because of the extreme metamorphic history of these Isua rocks, there is no way the amino acids are indicative of great antiquity. Questions were asked by Towe, French, Barton; and a comment by Hoering.

     How wonderful it will be when the geodynamics program of NASA begins to make measurements! Ed Flynn described a variable-based laser pulse interferometry system, which will enable measurements on the present, motion of tectonic plates, their deformation, formation, and relationships to one another. Currently, measurements are being taken on the San Andreas fault, but will eventually extend to all active faults. Flynn concluded by saying there is a difficulty for every solution, and all mole hills can be made into mountains. Chayes(2); French; Barton; Thornber; Stewart (3); Toulmin; and Lierman asked questions.

     Quarterly Beer Report:  Revenues rose sharply in early March and continued to remain strong during the end of March and early April: the high for the 3 meeting period being $29.50, and the low, $22.75. On April 22, perhaps due to the Reagan administration's hardline on the budget, revenues plunged to $3.00. Several officers of the Society believe the decline does not, in fact, reflect an accurate indication of current donation trends.  Beer will continue to flow; keep those dollars coming. The meeting was adjourned at 9:46 p. m. and attended by 64 people.

            Respectfully submitted,

            [signed Marilyn Estep]

 

Geological Society of Washington

13 May 1981

     The 1082nd meeting of the Society was called to order by President Rank in at 8:10 p.m. The minutes were read, corrected and approved. Ten new members none of whom were present were introduced. There were two visitors and Bob Decker, former president of IAVCEI.

     There were four announcements including:

     (1) Our new delegate to AAPG is Wally de Witt and alternate is Roger deAmato.

     (2) GSW conducted a successful and enjoyable field trip to the Roseland district Ti mine in Virginia. The members expressed their thanks to the leaders and the organizer of the trip.

     (3) U. of Md. Geo. Dept. graduate program: Funding for the graduate program is forthcoming starting 1982.

     Informal communication:

     Roy Clark spoke informally about the occurrence of pinhead sized diamonds in a rare land of iron meteorite that was discovered in a "mobile mine" i.e. a glacier in Antarctica in 1977. The origin of diamonds in meteorites has been a subject of debate involving authorities such as late Sir Harold Urey and Herr Prof. Dr. Edward Anders. Theories postulated include (1) large parental body to produce enough static pressure; (2) small parental body for a reason this surrogate secretary failed to catch, (3) shock loading, perhaps by collision in the asteroid belt, and (4) upon impact with the Earth. Clark and his coworkers have deduced through SEM and other studies that the meteorite had been subjected to at least 200 kb of pressure. They favor preterrestrial formation of diamonds, perhaps by impact with other asteroids in the asteroid belt.

     Talk no. 1

     Richard P. Sheldon, former Chief Geologist at USGS and now at  spoke about ice rings and the formation of atmosphere and hydrosphere on Earth. Sheldon postulated that Earth once had an ice ring similar to the ones around Jupiter, Saturn and Uranus. It was the cause of glaciers in low latitude areas and its gradual disappearance led to the warming of the Earth to its present conditions. Sheldon used the widespread occurrence of impossible interbedding of warm and cold climate deposits to explain how his hypothesis would work. Saturn's ice rings are kept in orbit by its many moons without which the rings would have collapsed. The shadow of the rings migrates seasonally. A similar situation on Earth would explain the impossible interbedding mentioned earlier. According to Sheldon's scenario, the pre Archaean Earth had a hot and thin atmosphere and a large thick ice ring wrapped tightly around the Earth. By the Archaean, some of the atmophile elements in the ice ring had been transferred to Earth's atmosphere which was thin, cold and reducing, and to primitive oceans, which were acid, reducing, contained a high concentration of rather nasty chemicals, and small in volume. Glaciers were everywhere.

     Concurrent increase in the Earth-Moon distance caused instabilities in the ice ring about this time and the ring separated into 3 separate rings. Sheldon held each ring responsible for the three major glacial periods in the Proterozoic Oceans gradually changed from icy to warm and from reducing to oxidizing.

     Sheldon admitted that his theory was outlandish and in conflict with other ideas about the outgassing history of the Earth such as the theory advanced by Rabey. However, he thinks the theory can be tested in various ways, for example by examining the changes in stable isotope composition. In closing, Sheldon challenged the audience to come up with alternative explanations for Proterozoic glaciers if they did not like his ideas. Questions were asked by G. Helz, D. Rankin, D. Harris, K. Towe, D. Milton, L Pavlides, and B. Jones.

     Talk no. 2

     George Helz of U. of Md. spoke on the use of 210Pb disequilibrium to date sediments and to derive sedimentation rates. 210Pb has a half-life of 22 years and is suitable for measuring time span of 50 to 100 years. 222Rn and 220Rn in the U decay series escape the soil into atmosphere where they decay to 210Pb. Since 210Pb is not stable in the atmosphere it is eliminated by rain and fallout. 210Pb is then deposited at the bottom of water bodies. Most of excess 210Pb in sediments or the amount of 210Pb in excess of what would be there by in situ decay of U, Th, and Ra contained in the sediments, is derived directly from the atmosphere. Only a small percentage is derived from watershed. A typical profile of Pb in the sediment core shows a exponential decrease down section to a constant level that represents a steady state between production and decay of 210Pb and is reached after about 100 years. The depth below the sediment-water interface to where steady state level is reached, then represents about 100 years worth of sediments and the average sedimentation rate for that particular location can be calculated. Bioturbation of sediments artificially increase the sedimentation rate by mixing the upper section of the sediment column and making it appear as though steady state 210Pb levels start deeper in the section than if the column were left undisturbed. The search for undisturbed sediments in such high energy estuarine areas such as the Chesapeake Bay can give valid but not useful sedimentation rates. Helz and coworkers measured sedimentation rates ranging from less than 1 mn/gr to 42.6 m/gr in cores from 17 coring sites in the Chesapeake Bay. Most of the measured rates were too high to fit the known transport modes within the bay. Mass balance calculations which took into account the input into the Bay from Susquehanna River and shore erosion and the sinks in the Bay and escape into the Atlantic confirmed that the assemblage of measured data indicated 4 times more sedimentation rate. Also the Bay receives about 1 decay/cm2/yr of 210Pb and the measured sedimentation rates suggested the fallout rate to be 5 times larger. However, the measured sedimentation rates were valid rates as demonstrated by a close agreement between the concentration levels of DEHP in the sediments and production of DEHP in factories located nearby and also by the concentration profile of 137Cs in the sediments. Helz concluded that even though each undisturbed core gave valid sedimentation rate for that particular site, as a group, the measured rates could not be used to arrive at the sedimentation rate on a regional scale. He attributed the cause of this discrepancy to the anomalous nature of undisturbed sediments or quiet areas in a high-energy estuarine environment. Questions were asked [end of ¶ --Ed.]

     Talk no. 3

     Dick Fiske of National Museum spoke on the relationships among volcanic activity, scientists, and politicians, in particular, the [word missing -- Ed.] on the island of Guadeloupe in 1976, and a successful harmonious operation on St. Vincent in 1979. The residents of islands in the Lesser Antilles have learned their lesson from the 1911(?) St. Pierre incident and respect their volcanoes. Therefore in August of 1976, when increased seismic activity and ash eruption was observed on the island of Guadeloupe, a French colony, teams of scientists were called in, and the inhabitants were evacuated from nearby cities and villages. However data necessary for accurate comparison between the renewed activity and quiescent states were rather meager, and the droves of scientists who arrived from France were not experienced volcanologists. Moreover, two teams, one headed by Taziell and the other by Allegre went to war with each other to the delight of the French Press. Meanwhile, the volcano continued to smolder but did not erupt in the catastrophic manner predicted by the team with decidedly alarmist views. French government was caught between the scientific teams at war with each other. Unable to decide whether to end the evacuation, the government called in foreign scientists to pass judgment on the French scientists. At that time mistakes such as wrong identification of erupted ash particles came to light. In contrast to this colorful yet unsuccessful attempt by scientists to contribute their knowledge and skill to protect the inhabitants from dangerous volcanic eruption, on the island of St. Vincent, a small team of experienced volcanologists made their contribution uneventfully and quietly. The event was the eruption of La Sonfriere in 1979. The team member included speaker, Dick Fiske, himself. Volcanologists had already been collecting seismic and deformation data since 1977. So when eruption started, they had a solid body of data to base their judgment on. One unified team was in charge of operations and kept the Government of St. Vincent informed. The Press was informed only through the Government spokesperson. Fiske compared the two incidents and stated that the success on St. Vincent was due to existence of complete data base, presence of experienced scientists who worked together, and made only factual statements, and because the press was prevented from making outrageous statements to alarm the public. The lesson seems to be that if scientists must face the public and politicians, they should keep the disagreements amongst themselves and present a unified front, and that it helps to have a volcano that is cooperative. Questons by R. Decker, G. Helz, F. Chayes, M. Foose, and R. Tilling.

     The meeting was attended by 88 (plus or minus 3) people, and was adjourned at 10:28 p.m. This was the last meeting of the year until September. It is the humble opinion of this surrogate secretary that no matter how interesting a topic, speakers should observe the 20 minute limit for their presentation.

     Respectfully Submitted

     Emi Ito, Surrogate for M. F. Estep

     Meetings Secretary

 

Geological Society of Washington

Minutes of the 1083rd Meeting

     September 23rd, 1981

     The 1083rd meeting of the Geological Society of Washington was held on September 23rd, 1981 in the John Wesley Powell Auditorium. The meeting was called to order at 8:05 p.m. by President Rankin. The minutes of the 1082nd meeting were read, corrected and approved. Names of new members elected at the September Council meeting were not announced due to administrative difficulties. Four visitors were introduced. The death of Henry Faul of the University of Pennsylvania, a former faithful Society member, was announced.

     Mary Mrose, Membership Committee chairperson, made a strong plea for encouraging new members to join GSW, pointing out the Fall bargain basement rates. Non-duespaying members were threatened with imminent removal from the rolls.

     Ed Roedder, USGS, gave an informal communication on the so-called microfossils in 3.8 billion year old sediments from Isua, West Greenland. These alleged microfossils had been dismissed by a consortium of distinguished scientists as "mere" fluid inclusions, thus triggering Roedder's ire. He demonstrated in a few well-chosen phrases that the objects in question were actually "negative crystals"--limonite-stained cavities formed by weathering-out of iron-rich dolomite crystals. They are not fluid inclusions. Questions by Brian Mason and Dan Milton.

     The first paper on the regular program, by Bob Hazen and Larry Finger of the Geophysical Laboratory, was titled, "The density paradox and other puzzles: insights from P-T crystallography on crust-mantle phase equilibria." Bob Hazen, who presented the paper, described techniques for accurate crystal­-structure determination at very high temperatures and pressures, simulating mantle conditions. He pointed out some surprising implications of these studies. Cation-oxygen distances may actually be longer in high-pressure than in low-pressure phases of the same composition, although density increases due to increased packing efficiency; for example, in the stishovite-versus-quartz forms of SiO2. This increase in bond distances means the higher--pressure phases may not be as rigid, and the seismic velocities may be lower; that is, seismic velocities may not always increase with density. Hazen showed that the results of high pressure-high temperature crystal chemistry may place limits on models for convection in the mantle, perhaps favoring a 2-layer model. Questions were by Toulmin, Roedder, Dan Milton, Robertson and Rankin.

     Maria Luisa Crawford of Bryn Mawr College next talked on "Metamorphic and Structural History across the Work Channel Lineament, Coast Plutonic Complex, British Columbia." She described work she and Link Hollister of Princeton have done in this region, especially efforts to relate the complex metamorphic geology to the regions of "displaced terranes" just to the north in Alaska. The protolith of the B.C. metamorphics is unknown. Major differences occur across the work lineament: to the East, low pressure-high temperature rocks; to the West, fairly high-pressure rocks. Crawford described four lithologic "packages" in the region, differing in rock types, degree of metamorphism and deformation. Efforts to trace this pattern northward into Alaska have yielded some promising initial indications. Questions by Zen, Arth, Dutro, Lyttle and one other.

     The third talk, by Wayne R. Sigleo, USGS, dealt with "Impact of climatic change and early man on late Quaternary landscape evolution in Tasmania; Australia." In studies near Hobart in Southeastern Tasmania the speaker recognized Pleistocene deposits indicating two sequences of glaciation. The complex Holocene stratigraphy was unraveled in part by using the evidence of Aboriginal hearths to demonstrate stratigraphic breaks. Some sand sheets were definitely attributed to disturbance by man of older deposits. In answer to a question, the speaker conjectured that humans may have liked to camp on sand sheets because snakes didn't like to live there, among other reasons. Questions by Crowley, Crumb and Rankin. The meeting adjourned at 10:05 p.m., attendance: 90±3. Respectfully submitted, Dan Appleman, surrogate surrogate secretary.

 

Geological Society of Washington

14 October 1981

     The 1084th meeting of the Society was called to order by the President Doug Rankin at 8:08 p.m. The minutes were read and approved. There were five visitors and an undetermined number and identity of new members.

     Carl Thornber the Public Service Committee Chairman is planning a fall field trip on November 21st. Brian Levy will lead the group to the North Culpepper Basin to look at contact metamorphic rocks.

     Marc Einaudi of Stanford University and the Geophysical Laboratory discussed correlations of metals, geological environment, and garnet/pyroxene composition in predominantly calcic skarn deposits. By looking at the gangue in addition to the ore, he related the oxidation state of various skarns to specific ore metal types and projected that this technique may be useful in exploration. Skarns are quenched products of magmatic fluid: their compositions vary as the fluid evolves from the magmas and the approach of studying metasomatic effects in conjunction with the mineral and metal compositions of the ore body will result in the delineation of the events, which have occurred along the geochemical pathway to ore formation. Questions were asked by Henley, Sato, Yoder, Zen (2), Robertson, Barton, and Toulmin.

     The second talk of the evening was by David Veblen of Johns Hopkins on the use of high resolution transmission electron microscopy as a tool for determining non-periodic mineral structures, solid-state reaction mechanisms, and the structure of fine-grained minerals. For example, the structure of the silicate chain mineral, Jimthompsonite, can now be determined, which is much to the relief of many Harvard graduates and metamorphic petrologists. Questions were asked by Appleman, Yoder (2), Towe, Millholland, and Ross. Comments were made by Towe and Robertson.

     Isotopic variations of samarium and neodymium can be used to examine mafic rocks not easily dated with uranium and lead. Rick Carlson of DTM examined lunar and terrestrial basalts and found that most of the crustal evolution on the moon occurred early in its history from 3.1 to 4.6 billion years ago and is indicated by conservative neodymium isotope ratios. On the Earth, however, continuous igneous activity has caused continuous isotopic depletion of the mantle. Differences in bulk chemistry and bulk masses of the moon and Earth may have caused these differences in planetary differentiation. A question was asked by Towe.

     The meeting was attended by 74 people and one or possibly more projectionists in need of either sleep or glasses or both. The meeting was adjourned at 10:03 p.m.

     Respectfully submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

27 October 1981

     he 1085th meeting of the Society was called to order from chaos at 8:18 p.m. by President Doug Rankin. The minutes were read and approved. There were nine visitors, and at long last, 21 new members were officially elected to the Society. There were three announcements: First, the fall field trip will be held on November 22, a Sunday: contact Carl Thornber in order to sign up. Second, the GSA is sponsoring a short course on Recent Advances in Organic Geochemistry to be held at the Geophysical Lab in March 1982. Third, the Nominating Committee, consisting of Simkin, Dutro, Rumble, Hatch, and Zen, announced the slate of officers for 1982.

     There were two informal communications: After stripping the "Wingate Sandstone" in S. E. Utah of its old and trusted name, Thomas Messenger then proceeded by a highly ingenious method to rename once again this rock, "Wingate Sandstone". Wingate St. in Moab Utah, if followed for a sufficiently long distance, will pass by the sandstone now named after it. Question by Zen. Dan Milton reported on a recent dinosaur meeting where the geological, biological, and climatological influences on dinosaurs were discussed. There were no dinosaurs in attendance. A question was asked by Toulmin.

     In the first formal communication of the evening, Judith Ehlen of the U. S. Army Topographic Laboratory, described her attempts to define better photographs of rocks by the relative terms phototone and texture. Without prior knowledge of the field area, which consisted of bare rocks at the New Mexico/Texas border, she used shape, relief, and slope arrangement to determine drainage types corresponding to rock types. Milton, McDade, Smeed, Robertson, Estep, Greenwood, Dross, and Rankin asked questions. Brinker commented on the military's use for this information.

     Mark Settle of NASA reported on results of the MAGSAT mission, which was to measure, once the data had been reduced, the earth's magnetic crustal anomalies. After removing the main field and the ring currents, positive anomalies can be seen in the Sierras, the Colorado Plateau, and the Oklahoma Plateau, which in particular is called the Kentucky anomaly. Questions were asked by Robertson, Haycock, Carter, and Dross.

     Using a series of hieroglyphic, yet effective, equations to model groundwater movements and fluid properties, Leonard Konikow of the USGS described an area surrounding the Rocky Mtn. arsenal, a site where pesticides and nerve gas products were added to the groundwater for approx. 13 yrs. The comparison of actual pollution and that predicted by Konikow's model was strikingly similar, and this technique could be useful in future polluted areas. "Pollution by dilution" and "Pollution by removal" as methods for treating serious, long-term waste problems are fraught with complications. Prevention is the best cure. Questions were asked by Segovia, Hatcher, Davis, Wood, Dross, and Milton.

     The meeting was adjourned at at least 10:25 p.m. and was attended by 64 people. Semiquarterly beer report: The average meeting attendee contributed an average of 32.2 cents for refreshments, this value being significantly higher than a value calculated for only rich, beer drinker in the first quarter of this year: that value being 19.5 cents.

     Respectfully submitted,

     Marilyn F. Estep, Meetings Secretary

 

Geological Society of Washington

18 November 1981

     The 1086th meeting of the Society was called to order at 8:09 p.m. by President Doug Rankin. The minutes were read and approved. There were 7 visitors. The Finance Committee reported that the Society was slightly in the red this year, but no increase in dues is forecast. The Geological Society of Washington is a tax exempt organization, so donations are tax deductible.

     The first paper of the evening was delivered with polished style by Anthony Naldrett of Univ. of Toronto on the bases of prospecting for sulfide ores by finding tectonic settings where metal-rich magmas will come into contact with sulfur rich sediments. A number of large and spectacularly rich ore deposits occur on continental' margins or at previous midcontinental rift zones. With the use of microprobe data and sulfur isotopic compositions of ores it is possible to determine genetic models. Questions were asked by Barton and Foose (2).

     The second talk of the evening was by Dan Miller, the Assistant Secretary of the Dept. of the Interior on the occurrence of oil and gas in the Western Overthrust Belt. With a gleam in his eyes only a wildcatter can have, Miller unfurled a tale of a geologist's heaven, an oil company's dream, and possibly an environmentalist's nightmare. Increasingly sensitive seismic data has enabled the discovery of deeply buried oil sediments, which have been curled under layers of granite. The Western Overthrust Belt is a major tectonic feature in many states in the West and promises to produce an increasing amount of America's petroleum. Questions were asked by Barton, Robertson, Kane, Hewitt, Noble, Appleman, Kinney, Gerrard, and Doan (2).

     The auditorium was packed with 122 attendees and the meeting was adjourned at an early 9:37 p.m.

     Respectfully submitted,

     Marilyn F. Estep

 

Geological Society of Washington

11 December 1981

     The 1087th meeting of the Society was called to order at 8:10 p.m. by President Doug Rankin. The minutes were read and approved. There were 8 new members and no immediate recognition of any visitors, however, one or two surfaced at the Annual Meeting and were introduced. Respects were paid for Nancy Wright.

     Doug Rankin then delivered his Presidential Address, which was punctuated periodically with morals. For example, "do not underestimate the amount of time it takes to get data from the computer." Rankin described the geological setting and chemical composition of two climactic volcanic eruptions: the Black Cat Formation in Maine and the Wilburn Formation on Mt. Rodgers in SW Virginia. For 25 years, this President and his wife studied these areas and were able to map flow units based on pumice lump size. The tufts in Maine, a volume of approx. 500 cubic km of rock, have been quasi-horizontally flattened. Those of Virginia with a volume of 250 cubic km were compacted to a lesser extent, although the formation was subjected to greater deformation. For comparison, the volume of the Mt. St. Helens eruption was approx. 1 cubic km.

     The chemical compositions of the two formations were distinct: the Wilburn formation is more highly fractionated, indicating a bimodal magmatic source. Rankin believed the sources of the Black Cat formation were a differentiated magma from the lower crust and a component of geosynclinal sediments.

     Estep attempted to open the paper for questions and discussion, and was summarily dismissed. The attendance was 100 ± 20, the large error due to the fact that the secretary generally counted heads during question periods.

     Respectfully submitted,

     Marilyn F. Estep

 

Annual Meeting

9 December 1981

Geological Society of Washington

     The Annual Meeting of the Society was called to order by President Rankin after members had swilled enough beer to be able to thoroughly digest and appreciate Rankin's Presidential Address. The first order of business was the reading of the minutes from the last Annual Meeting by Tina Silber. Silber apparently had not fully digested Rankin's talk and was no doubt closeted away somewhere making private notes for later discussion. Estep, thus, proceeded with her account of the state of the G.S.W. meetings for 1981. The report was accepted, and a weary but pleased Estep continued out her short stint by observing the remainder of the meeting with relief. Silber reappeared amid applause and delivered her addresses, which were accepted. The status of the Council for 1981 was one of reserve.

     Mike Foose then approached the podium nervously eyeing the crowd for signs of rotten eggs and tomatoes. After the previous year's debate on dues increases, Foose was prepared this time. He announced no dues increase, which calmed the wild beasts, notably Dutro, lurking in the audience. He did project a slight deficit for 1982 of $465.00. The specter of the mailing list and meetings notices was raised and buried. The Society had $11,407 in assets on this date.

     Mary Mrose then took the podium and delivered her state of the Union address on membership. The audience accepted the personal chiding with good humor, and applauded Mrose's good job and valiant attempts. There were 65 new members last year and a total of 981 members in the Society.

     The Chairman of the Public Service Committee, Carl Thornber, reviewed his term in office. He charged the Society to continue supporting field trips and local science fairs of note, during Thornber's tenure as Chairman of this committee no new field trip guides were published, although he made repeated attempts to unload old editions.

     Joe Arth presented the Best Paper Award to Leo Hickey of the US National Museum for his talk on "Plant evidence on dinosaur extinction-out with a bang or a whimper." Sometime in May or April, Hickey received the highly coveted and elusive silver cup, but left the meeting with a check for $200 clutched in his hand. Michael Engel of the Geophysical Lab won the 2nd Best Paper Award for his talk on amino acids in the Isua rocks of Greenland. Engel, although not at the meeting, was totally astounded by the award and promised to treat all of his colleagues to pizza. The Great Dane Award for the Best Informal Communication went to Ed Roedder of the USGS for a discussion on the Evaluation of alleged microorganisms in early Archean sediments of W. Greenland.

     The Highlight of the meeting was Norm Hatch's discourse on the philosophy and potential capabilities of the Sleeping Bear Award. The audience roared with Norm as he delivered a lengthy treatise; several members were nominated; the  [that's all there is -- Ed.]