GSW: 1982 MEETING MINUTES

 

Geological Society of Washington

1088th meeting, 1/13/1982

     Cancelled due to blizzard.

 

Geological Society of Washington

27 January 1982

     The 1089th meeting of the Society was called to order by President Toulmin at 8:04 p.m. Before President Toulmin could tackle any new business the conglomerate of geologists that sits in the first few rows demanded to know what happened to the 1088th meeting. Toulmin announced that when a meeting is cancelled as that one was, it retains its number and that's that. The minutes for the 1087th meeting were read. Rankin corrected the minutes to read that the volcanic rocks he discussed were members not formations. Six new members had been elected to the Society that day by the Council Three visitors were introduced: Dave Frischman of the USGS in Denver; Dan Blake from the University of Illinois; and Greg Eddy of TRW.

     President Toulmin then announced that he was taking the responsibility for stimulating more humor at meetings. You will remember that Hatch begged for such an action at the last annual meeting. To this end he pulled an anonymously donated Teddy bear from a large plastic garbage bag and gave it a seat of honor on the stage. Teddy will sit in this position at every meeting. Zen protested that the bear was not sleeping at all, and was in fact staring at the audience. Toulmin responded witheringly that Teddy will not be able to sleep until he detects real, spontaneous humor. Then, with a total lack of respect, Lipin asked if, we really had to look at "That Thing" all year.

     Program Chairman Dutro announced that he needed to find several speakers for upcoming meetings in the next two days, and even threatened to give a talk himself if no one volunteered. Simon of the Public Service Committee asked for suggestions for field trips for the Society.

     J. Wright Horton of the USGS, Reston, presented the first talk on structural complexities in the Kings Mountain belt in the Southern Appalachians. These rocks that represent one of the largest Li resources in the world have received the attention of many geologists before Horton and he presented at least 20 models that are in the literature explaining the nature and position of the Kings Mountain belt. Frustrated in achieving a consistent and absolute age for the dominant schistosity in the Kings Mountain belt, Horton can at least say that this schistosity is either Taconic or Acadian. In conclusion, Horton felt that the Kings a Mountain belt has fundamental similarities with the Charlotte belt to the east and that these belts were joined by at least 388 m.y. ago, whereas the Kings Mountain belt has important differences from the Inner Piedmont to the west. It is separated from it by a major shear zone which forms a zone of metamorphic discontinuity and separates terranes of quite different structural styles. Questions by Rankin (2), Stewart, and Zen. Zen reminded members to give their names before asking questions and then neglected to give his own. This was balanced by the fact that when Lyttle asked Stewart to identify himself he gave the name Zen.

     The second talk of the evening was by Steven Stanley of Johns Hopkins who wondered why there were mass extinctions of mollusks in the last 22 m.y. in the Atlantic Coastal Plain. After advising the membership to avoid the present beaches if you are searching for mollusks and head inland a bit, he went on to discuss factors that might affect rates of extinction in various critters. He pointed out that if you were a bivalve you had a better chance of surviving if you had a long siphon. The non-siphonate forms and the poor scallops didn't seem to have a chance. One important conclusion was that major cooling events can greatly increase rates of extinction, and Stanley pointed out that 3 m.y. ago continental glaciation began in the northern hemisphere and the strengthening Gulf Stream cooled much of the Atlantic Coastal Plain. At this point even though siphonate bivalves would appear to have had an edge over the lowly non-siphonate forms and scallops, it did not do them much good as mass extinction struck species randomly. Questions by Stewart (2), Rankin, Milton, Towe (2), Zen (2), Kinney, Stifel. No one believed it when Zen said that he was almost too embarrassed to ask a question. It was also decided that it took "One hell of a catastrophe" to produce a 6 m thick shell bed.

     The final talk of the night was presented by Craig Rightmire of TRW in McLean. He took the novel approach of looking at methane in coal beds as a potentially important resource instead of just a dangerous nuisance. He made a convincing argument that it is quite feasible to produce the gas as a marketable energy source instead of just degasifying the coal beds so they can be mined. One major problem is that a large amount of water must first be removed before much gas will flow. Stanley pointed out that there are up to 700 coal bed methane-­producing wells in the Mary Lee/Blue Creek seam alone. As with most resources this one is beginning to generate its own brand of legal problems. Pennsylvania law now states that you need the permission of the coal owner before you can stimulate his property to produce methane. I should hope so. Questions by Davis, Stewart, Peggy Appleman, and Lipin. Lipin was particularly interested in the definition of a "negative decline curve."

     Attendance was 80 and contributions for beer was $20.00. The meeting adjourned at 10:00 p.m.

     Respecfully submitted,

     Peter T. Lyttle, Meetings Secretary

 

Geological Society of Washington

10 February 1982

     The 1090th meeting of the Society was called to order by President Toulmin at 8:07 p.m. Fred Simon called for volunteers to judge science fairs and also announced that both Wayne Newell and Lou Pavlides had agreed to lead field trips for the Society in the upcoming year. He also asked for a show of hands of those who would be interested in attending a two day field trip. A show of approximately eight hands put to rest that noble idea, perhaps another year. There was an announcement that the Washington Organic Geochemistry Colloquium is having its first meeting on Thursday, February 25 (that is tomorrow night) at the Geophysical Laboratory. John M. Hunt will talk on "Applications of pyrolysis in organic geochemistry." Refreshments begin at 3:30 p.m. and the lecture is at 4 p.m. With a charming lack of modesty Andrew Stancioff of Frederick, Maryland introduced himself to the Society. He has been a member of the Society in the past and wants to rejoin. He was informed that upon the receipt of $7.00 this would be accomplished.

     The first talk of the evening was presented with an even greater lack of modesty by Ellis Yochelson of the USGS It may be premature to say that Ellis has given up his quest for the Great Dane award, but by his own admission he has begun a frontal attack on the best paper award because he "is after the big money". Ellis used the unusual format of giving several talks within a talk and looked upon his several follow up talks as encores, claiming that he was only responding to the overwhelming skepticism that he felt was emanating from the audience. As the room was quite dark and much of the time there was absolute silence in the hall, this just shows what a sensitive human being Ellis is. The subject of his first talk was an UNUSUAL Devonian jellyfish. This critter propelled itself by means of a built in sail and had "what is loosely called a liver." Ellis noted that today fish are fond of eating jellyfish and in the Devonian there were lots of fish. Ellis' second talk was about a primitive organism that was the granddaddy of all mollusks, or so many people have thought in the past. The plot thickened when he pointed out remarkable similarities between a supposed mollusk from the lower Ordovician Stonehenge Formation and his Devonian jellyfish. Similar creatures have now also been found in a lower Cambrian shale in California. The moral of the story was that there are many organisms that have been assigned to the wrong phyllum and are not mollusks at all. Questions by Krantz (2), Milton, Towe, Stewart, and Dill. Stewart noted that his was asking his question for the absent Bruce Lipin as he was sure that Bruce would want to know what other kind of sailors there are besides "by-the-wind." Milton noted the wonderful preservation of the critters considering the conspicuous lack of hard parts in a jellyfish.

     The second talk of the evening was presented by Selwyn Sacks of the Department of Terrestrial Magnetism. Using subduction zones in southwest Japan and western South America as examples, Sacks suggested that given certain conditions some subducting plates may have geometries more complex than tile commonly accepted slab dipping uniformly at 30°. There are anomalous areas such as Central Peru where few if any earthquakes are detected. Sacks pointed out that this is not evidence that there is no subducting plate in these areas. His model suggests that in certain areas the subducting plate initially descends at a 30° dip, then flattens out over a wide zone, and then resubducts at 30°. The important thing to consider is why does the slab flatten out. Sacks suggested that since the coldness of the slab initially makes it sink, it is important to look at the thermal structure of the subduction zone to predict what happens at depth.  Much, depends on how fast the plate heats up and on the temperature difference between the subducting plate and the surrounding asthenosphere. If the temperatures can remain high enough to retard transitions such as basalt to eclogite, the slab can retain a low enough density to be buoyant and remain flat instead of descending at 30°. And if there isn't a mobile high T asthenosphere in contact with the subducted crust no magma will be produced. Questions by Lomond,  Neuman, and Robertson.

     The final talk was presented by Herbert Frey of NASA at Goddard. He discussed a class of Martian craters that are all less than a km in diameter. Looking primarily at areas on Mars where they have the best imagery such as the knobby terrane of Sydonia, as well as Utopia and Elysium, Frey pointed out that these small features have a remarkably consistent crater to cone ratio clustering around 0.45. Because of this he suggested that they all have a common origin, thereby assuming, I would imagine, that the craters are all found in rocks of the same composition and are of the same age (kind of a big assumption). Looking at terrestrial volcanic features in the hopes of finding an analog that might explain what these things are, Frey felt the closest thing we have on Earth are small craters found around the shores of Lake Myvatn in northern Iceland. These craters formed when lava flowed over wet areas at the edge of the lake, trapping the water which then proceeded to explode and form small craters. The problem with this analog would be that it seems unlikely that a cone would form in such areas. Questions by Milton, Sato (2), Allen, Stancioff (2), Dutro, Tilling, Towe (2), Stifel, Robertson.

     Eighty people attended the meeting and in their usual overly generous manner donated approximately 2 bits each for the beer. We have no worries about getting rich off of beer donations. The meeting adjourned at 9:52 p.m.

     [signed Peter T. Lyttle]

 

Geological Society of Washington

24 February 1982

     The 1091st meeting of the Society was called to order by President Toulmin at 8:09 p.m. As the beer had arrived only 5 minutes before, the crowd was unruly and refused to take their seats until they had a beer in hand. The secretary read the minutes of the 1090th meeting and these were accepted without correction, something new in the recent history of the Society. A pleasantly large number of visitors was introduced including: Daniel Santos of the University of Maryland, Professor Jim Soroff from SUNY Binghampton, Jim_____ from NASA, Tom Hahn from Beloit, and last but definitely not least Peter Stifel introduced at least 6 students from the University of Maryland. Fred Simon announced that even though there have been several volunteers to judge science fairs since the last meeting he is still looking for some more. He announced that Newell, Jacobson, and Ward are leading a field trip for the Society on April 17, a Saturday. Fred also asked for ideas and volunteers for a field trip for science teachers. Elaine Weed plugged the upcoming joint NE-SE GSA meeting to be held at the Shoreham on March 25-27. Penny Hanshaw announced that the USGS is having its annual Pick and Hammer Show on Saturday February 27. President Toulmin announced the recent death of J. Fred Smith.

     The first talk of the evening was presented by Alexander Malahoff of NOAA on ocean floor poly metallic sulfides. For much of his talk one wondered whether he was the chief propagandist for the New Zealand travel bureau. His talk dealt with the structural development of rifts and the products produced by rifts and began with brief glimpses of rifts on Hawaii and in the Wairaki geothermal field in New Zealand. He commented rapturously that visiting these areas can be a truly religious experience, but that if one truly is seeking penitence a visit to a rift on the ocean floor is in order-in his case it was made to the Galapagos central rift. In some of the most poetic words uttered at recent Society meetings, Malahoff characterized 2 rift blocks separating as "lost lovers in space". He proceeded to show spectacular pictures taken from Alvin and a steel cage called "cheap tow". "Cheap tow" from Lamont is not to be confused with "deep tow" from Scripps. In the first of these pictures he showed some huge worms which he assured us were both gutless and highly sexed. The hot waters emanating from the rift support a number of other organisms such as huge clams. He showed us a bed of clams that had died because the rift block had moved away from the hot waters at the central rift and claimed that this was analogous to turning off the water in a New York tenement. The main point of his talk demonstrated that there are huge deposits of iron and copper sulfides deposited as precipitates from the hot waters at the central rift. They came upon these deposits on a large percentage of the dives they made. These deposits contain 30 % Fe, 10 % Cu, but relatively little Pb and Zn. Questions by Sohn, Peggy Appleman, Rankin, Hemley, Stifel, Zen, Robertson, Simkin, and Siegel.

     The second talk was given by Cliff Nelson of the USGS in Reston on federal support of paleontology, or why there are paleontologists in the USGS Upon introducing him President Toulmin said that the title of his talk asked a question many of us had been asking for years. Nelson announced that he had considered calling his talk "Fossils in government". He pointed out that in the early days of U.S. geology, especially in pre-Civil war days, there were extremely few paleontologists participating in the major expeditions out west. If any paleontology was done, it was by contract on the collections made by other scientists. In 1877, the government established the first permanent job for a paleontologist, Charles White. The first paleontologist hired by the USGS was the "new man from Utica" Walcott. When Powell took over the USGS, the paleontologists became more independent and loosely organized (perhaps a good description of the set-up today). Question by Malahoff; none by paleontologists.

     The final talk of the evening may well go down in the Guinness book of GSW records for a variety of reasons and anyone that was here is not likely to forget it. Dennis Stanford of the Department of Anthropology of the Smithsonian gave us a fascinating, if rambling, account of how, and more importantly when, man arrived in the new world. For a Society such as GSW that prides itself on short and concise talks, I think it is fair to say that Stanford's talk magnificently failed to conform to our norm. When President Toulmin approached the podium about 5 to 10 minutes after the allotted time was up, Stanford appealed directly to the audience and said he still had a great story to unfold. Since Stanford had kept us captivated with tales of blood and gore up to that point, Zen responded to Stanford's plea and invited him to continue with his talk. Needing no more encouragement, Stanford launched into a 40 minute addendum. The conservative view in anthropological circles holds that man has not been in the new world for more than 12,000 years. And even though Stanford admitted that there is absolutely no hard evidence that man has been here for more than 14,000 years, he placed himself firmly in the more liberal camp by suggesting that man began as a mongoloid strain in North China around 30 to 40,000 years ago and moved to North America around 20,000 years ago.  Stanford's own personal story seemed to begin at the "Trick or Treat" site in northeast Colorado in 1975. It seemed simple enough at first, but before the evening was through we were taken to Texas, to Alaska, to the bears cage at the National Zoo, to an elephant slaughter in Front Royal, and to the coroner's office in Washington, D.C. Stanford pointed out that at a number of sites dated considerably older than the average Clovis culture age of 11,000 to 12,000 years, there are large numbers of mammoth bones that look like they have been broken (and here the story becomes controversial by suggesting that these bones have been pointed and tooled by man). He notes that at many sites only the long bones have been broken and feels this argues against natural agents other than early man: He did point out that the bones could have been broken by the ma m moths walking over them. It appears that Stanford believes in the dictum that seeing is believing. When trying to decide whether large animals such as bears could break mammoth bones, he had a graduate student from Catholic University feed bison bones to Juneau, a bear at the National Zoo. Before the student could retrieve any of the bones, Juneau had eaten all the evidence. When trying to decide whether early man could slaughter a mammoth with simple tools, Stanford borrowed a dead elephant from a Boston zoo, had it transported to the Smithsonian sanctuary in Front Royal, and with a band of grisly friends tore the beast limb to limb with their bare hands and simple tools. Stanford pointed out that the 30,000 year dates reported for a Clovis culture site in Texas are, in fact, spurious. The age was determined on a piece of lignite that the Clovis people apparently burned. Questions by Sohn, Marty Toulmin, Friz, Malahoff, Barnard, Williams, Tracey. The meeting ended with a heartfelt plea from Dutro to please allow us to get up from our seats and have a beer. The attendance, I am pleased to announce, was 119, much better than the average for the past few months. The beer donation was $30 dollars, suggesting that the 2 bits per person donation that I mentioned at the last meeting may be a universal constant. It has held true for all the meetings under President Toulmin. The meeting adjourned at 10:15 p.m.

     Respectfully submitted

     Peter T. Lyttle

 

Geological Society of Washington

10 March 1982

     The 1092nd meeting of the Society was called to order by President Toulmin at 8:04 p.m. In response to something Lyttle read in the minutes for the previous meeting, Rankin asked an irreverent question about the Toulmin regime which was appropriately ignored. Lyttle then announced that 14 now members had been elected to the Society that afternoon by the Council. Peter Stifel announced that the University of Maryland now has a new building for their Geology Department. The call for informal communications was answered affirmatively for the first time in recent history. Tom Dutro discussed a brachiopod that was named by a Pole in 1909 Dzieduzikia. Found in the Southern Urals and Morocco, it was eventually found by Gilluly in the United States in the uppermost Devordan in Nevada. This brach was also found in similar rocks in Mexico and Dutro used this to document 700 miles of offset that has taken place presumably since the Devonian. The most effective part of this short talk was when Dutro tried to mimic what a Rhynconellid brachiopod looked like.

     Mike Fleischer was called out of retirement to give the first talk of the evening. In excruciating detail he discussed the vital statistics for chemical abstracts for the last forty years or so. For the early years he showed that the number of abstracts doubled every nine years or so, and that between 1976 and 1980 a new trend that we can all be grateful for began, a sharp decrease. The year that the number of abstracts peaked was 1978, the same year Tom Dutro and Jim my Carter were Presidents. The burning question was what have the Russians been doing with all those chemists who used to write abstracts. Fleischer noted that if the Chinese become as advanced as the U.S. and Russia (and his definition of advanced was when they publish as many chemical abstracts per capita) the production of abstracts would be doubled. Questions by Sohn, Robertson, Zen, Toulmin, and Dan Appleman.

     The 2nd talk was given by Ina Alterman of NRC on the Roanoke recess and the juncture of the central and southern Appalachians. She introduced herself by saying that Bob Neuman once said she gave the longest talk ever given at a GSA meeting. Making it clear in the beginning of her talk that she is a northerner only recently transported to the southern Appalachians, she referred to the southern Appalachians as "the tail" being wagged by the body of the Central Appalachians. She contended that the southern Appalachians are not allochthonous with respect to the central Appalachians even though central Appalachian trends can be seen to underlie southern Appalachian trends in the Roanoke recess using aeromagnetics. Instead the southern Appalachians have been rotated westward with respect to the central Appalachians during a continental collision. Using the flashlight pointer on the screen to simulate Brownian motion, Alterman showed a major lineament on Landsat photos that trends northeastward along the Jackson River near Covington, Virginia. Claiming that this lineament is a major fault she suggested that much of the rotation was taken up along this fault. A question by Hatch suggested that the compressional room problems should have been more severe on the west side of the Appalachians in Kentucky rather than on the east side near Covington. Other questions by Rankin and Epstein.

     The 3rd talk of the evening was by Eric Force of the USGS who talked about Titanium resources in the United States. He summarized that the four major new Ti resources were tailing from new porphyry copper deposits, Colorado-type perovskites, a new process developed by Kerr-McGee to turn imported ilmenite into synthetic rutile, and domestic leached ilmenites from beach sands. He continually informed us how to spell the first names of various geologists since his own was misspelled on the GSW meeting notice. Questions Lipin, Zen, Sheldon, Robertson, Morgan, Toulmin.

     Attendance for the meeting was 96 and beer donations totaled $___. The meeting adjourned at a respectable 9:52.

     Respectfully submitted,

     Peter Lyttle

 

Geological Society of Washington

14 April 1982

     The 1093rd meeting of the Society was called to order by President Toulmin at 8:03 p. m. In the John Wesley Powell auditorium. From that moment until adjournment more than two hours later a person who will remain nameless sat in the front row directly in front of the podium sound asleep. In my opinion this was a particularly amazing feat in the light of the high quality of the three excellent talks that followed. The minutes were read and approved and the names of five new members were read. One of those new members was in attendance. Fred Simon, who is fast becoming a regular at this year's meetings, announced the upcoming April 17 field trip and the successful judging of a large number of local science fairs by GSW members. Treasurer Bob Tilling gave an informal communication on the financial health of the Society. When he asked for "the first slide please", we realized we were not going to hear the usual dry treasurer's report. Coining a new acronym that he hopes is now inscribed on every members heart- CNDL or Contribute Now, Drink Later-Tilling pointed out that we need to increase contributions this year in order to insure retaining the same dues next year. On multicolored charts, Tilling tried to convince us that all of the pertinent economic indicators for the last year mimic those of the years when we had previous dues increases. There was a slim ray of sunshine however. Contributions so far this, year have already far outstripped last years. Also, the total contributions for beer at this meetings end was approximately double the usual amount. Tilling also announced the first winner of what I am dubbing the Roadrunner award. This goes to the person who pays her dues the fastest, and this year a bottle of 1978 Cabernet Sauvignon (donated by our generous Treasurer) was presented to Ann Sangree. Now that the rest of us know the possible rewards there should be a stampede next spring.

     Three visitors were introduced: Dr. Jay from DOE, Breck Marshall from GW, and Mike Piepenburg from GW.

     Once again we had a response to the call for informal communications from Lindsay McClelland of the Smithsonian. He gave a volcano update on El Chichon in Mexico and Galoongoon in Java, as well as the latest on the "mystery cloud". The mystery cloud was sampled by NASA and is indeed the product of a volcano and most likely a basaltic eruption, but it will probably remain a mystery where it came from. Andesitic or dacitic eruptions at El Chichon beginning on March 28th have resulted in the deaths of possibly as many as 600 Mexicans. An eruption in Java that in many ways mimicked the May 18 eruption of Mount St. Helens also resulted in a number of deaths. Questions by Marsh, Rankin, Tilling, Zen, and Toulmin.

     Beginning the formal part of the program, Bruce Marsh of Johns Hopkins University talked to us on the life and death of magmas. Pointing out that most igneous petrologists and volcanologists spend all of their time studying only the very last seconds of the long and glorious history of magmas, Marsh concentrated on how a magma is born, how and how fast it ascends to the surface, and how we might be able to use the chemistry of igneous rocks to tell us something about these things. Whenever he left the theoretical realm and talked about real rocks he generally used the Aleutian island arc as his field area. Commenting that no matter how irregular the shape of the original magma source or chamber, experiments suggests that by the time the magma reaches the surface or near surface it is often arranged quite systematically in belts or linear patterns. That the Aleutian arc is really a series of straight segments instead of a simple arc may result from the fact that the descending slab is broken into staves. It was interesting to note that a number of his short linear segments were defined by two points. Marsh suggested that it was necessary to melt a surprisingly large percentage of the source rock before the melt can separate and begins its ascent­ something on the order of 30-50%. He also felt that much of the source rock was brought along as a mush and some melt "extracts itself on the way up". He felt that chemistry, particularly the rare earths can put tight bounds on the ascent curves and tell us something about the depth of extraction of the melt. Questions by Zen twice, Robertson, Ryan, and Sato.

     The second multiauthored talk on the application of nuclear magnetic resonance was presented by Pat Hatcher of the USGS Using a new technique that can study organic substances directly and non-destructively (known as solid state NMR), and concentrating particularly on 13C NMR, Hatcher and coauthors have begun work in two areas: 1) to understand the process of coalification, and 2) to look at kerogens in source rocks in order to predict what fossil fuels may be present or produced. He noted that kerogen derived from aquatic plants is responsible for the formation of petroleum and kerogen from terrestrial sources are involved in the production of natural gas. Present work under the auspices of a Gilbert fellowship on a golf course near Mangrove lake in Bermuda showed that there are benefits for hard working isotope geochemists. In Bermuda they are trying to observe the formation of paraffinic structures in humic compounds to see if they are precursors to algal substances. Questions by Sato (a short lecture in itself), Stewart, Hoering, Zen, and Estep.

     The final talk of the evening by Roy Bailey of the USGS dealt with his work unraveling the geologic history of the area around Long Valley caldera. Framing his talk at beginning and end by a discussion of recent earthquakes in the vicinity of Mammoth Lake, California, Bailey lead us through 3.5 m.y. years of igneous and tectonic activity. Between 3.5 and 2.5 m.y. extensive basalts erupted over the area when the eastern crest of the Sierra was only 200 ft high. Between 2.0 and 0.7 m.y. the first rocks associated with Long Valley caldera erupted as the Glass Mountain Rhyolite and the Bishop Tuff was laid down over an extensive area. Between 0.7 and 0.1 m.y. after the collapse of the caldera a rhyolite tuff covered the Bishop tuff and coarsely porphyritic lavas surrounded the central dome. On May 25, 1980 (the same day as the second major event at Mt. St. Helens) there were 4 magnitude 6 earthquakes near Mammoth Lake. Originally these were felt to be related to tectonism, but continued study of the seismic record suggests that they may be precursors to renewed volcanic activity. Bailey suggested that we may be seeing the beginning of dome building or the beginning of a new Bishop tuff sequence and until they begin to get a better idea which there will be extensive monitoring of the area. Questions by Ryan, Tilling, Apple man, Stewart, Zen, and Toulmin. Attendance was 98 (13 percent of which were women) and donations for beer were a  whopping $46. The meeting adjourned at 10:07.

     Respectfully submitted,

     Peter T. Lyttle

     Meetings Secretary

 

Geological Society of Washington

28 April 1982

     The 1094th meeting of the Society was called to order by President Toulmin at 8:08 p.m. The minutes of 1093rd meeting were read and, except for heckling from one of the Applemans that I did not properly identify which Appleman asked a question, were approved. Josh Tracey made a pitch for the AAPG, especially a committee whose business it is to conduct professional affairs. Someone from North Carolina State University held up a T-shirt which he said were for sale for $5. The following visitors were introduced: John Kroll from U.C. Santa Barbara, Jim Idell from Hanna Mining, Preston and Jan Cloud, Jack Somebody, Bob Laney of the USGS, Loren Stieff, and Tom Feininger of the Universite de Laval. Lyttle read the names of 6 new members elected that afternoon by the Council.

     The first talk of the evening was given by Gary Ernst who summarized the thoughts of a large group of American and Chinese geologists on recent work in Taiwan. In this tectonically complex area where two subduction belts come together, he concentrated on the contrasting metamorphic histories of four major tectonic belts. The Nanao-Suao basement complex recorded an amphibolite facies prograde metamorphism and a greenschist facies retrograde metamorphism; the outboard belt of the Juisui area west of the Longitudinal Valley retains evidence of a Late Cretaceous amphibolite facies event and a Late Cenozoic moderately high pressure event that produced a barrositic amphibole; the northeast corner of the island recrystallized during loading when it was caught up in the subduction zone and the rocks were very slightly metamorphosed; and finally the more exotic Coastal Range containing ophiolites that record several episodes of metamorphism and which was the last tectonic block added to the island. Questions by Zen twice, Lee, Dutro, Robertson, and Leo (whose question seemed planted since it allowed Ernst time for the rest of his conclusions).

     The second talk of the evening was presented by Ed Evenson from Lehigh University. Promising that he would not exceed his time limit because he had to go to the bathroom so badly, he prefaced his talk on evaluating the mineral resources of remote high alpine areas by studying the junk carried by medial moraines with a short Argentine update. We learned that Argentine soldiers staple on their insignia so that they can be changed quickly and are now using canvas bags to silence the guns on their tanks. Evenson pointing out that every medial moraine has 2 sides servicing 2 source or catchment areas, and each one is isolated from the next one added to the advancing glacier. These moraines pick up very little material from the bedrock they advance over, so they retain a faithful sample of their source area. Evenson made Ellis Yochelson look like a piker by fitting 91 slides into his 20 minute talk. Questions by Lyttle, Kroll, somebody, Zen, Toulmin, Leo, Ernst, and Robertson.

     The concluding talk of the evening was given by Tim Benjamin of Los Alamos on the Oklo natural reactor. Set in middle Precambrian unmetamorphosed volcanic and sedimentary rocks in the Republic of Gabon, the Oklo ore formed 2 b.y. ago. He suggested that to have a natural reactor 1 % of total uranium must be 235U, total uranium concentration must be high, the ore body must be greater than 0.5 m thick, water must be present, and there must be an absence of poisons. Benjamin spent much of his talk discussing certain fission products, that establishes that Oklo really was a reactor. He claimed that the radioactive elements were all contained near the natural reactor in the Francivillian sediments making geologic waste disposal practicable. A number of questions following the talk suggested that assumption might be a little premature. No systematic water studies have been done at Oklo and a number of fission products have totally left the system . Questions by Milton, somebody, Hoering, Zen, Robertson, Simkin, Hanshaw, and Toulmin.

     Attendance was 90 (17 % women). Beer donations totaled $___. The meeting adjourned at 10:04 p.m.

     Respectfully submitted,

     [signed Peter Lyttle]

 

Geological Society of Washington

12 May 1982

     The 1095th meeting of the Society was called to order by President Toulmin at 8:02 p.m. The minutes of the 1094th meeting were read and approved. Several visitors were introduced: Fred Barker, Earl Ingerson (?), Kay Behrensmeyer of the Smithsonian, and Ted Murphy of the Park and Planning Commission in Maryland.

     Jim Clarke of the USGS began the evening with an informal communication on the Falklands. He pointed out that the Falklands have been left behind relative to South Georgia by a major transform fault. Clarke also outlined areas of greatest oil potential in the Birdwood bank area where potential oil-­bearing sediments were greater than 1000 m thick and the water depth was less than 200 m. Clarke offered to retake the Falklands for the British, if they wrote his geologic report for him. Question by Gill.

     The first scheduled talk of the evening was presented by Juergen Reinhardt of the USGS, Reston. Discussing his work of the last few years in the Georgia­-Alabama Coastal Plain, Reinhardt pointed out that the sediments range from mostly continental in central Georgia to mostly marine in central Alabama and that crustal flexure may be a major controlling factor for sedimentation. High angle reverse faults found throughout much of the Atlantic Coastal Plain contrast with the normal growth faults in the Gulf. The transition area between these two tectonic regimes is the Warm Springs area where Reinhardt and others have been carrying out detailed mapping. He pointed out that with time offsets on most faults decrease. Reinhardt concluded that other structures in unconsolidated, sediments besides faults may be just as important in determining the neotectonic history. Examples given were injection of biogenically homogenized sediments, clastic dikes, and drop stones. Questions by Rankin, Sutter, Robinson, Lipin, and Robertson.

     Joe Donaghue gave the second talk on radiotracers in sediments of the Chesapeake Bay. The Susquehanna is the major contributor of water and sediment to the bay and there are four dams that trap sediment along the Susquehanna. Conowingo Dam is the only large one and is the major reason why only 46 % of the sediment entering the river reaches the bay. Donaghue and coworkers have found that using reactor-generated radionuclides (particularly 134Cs) they have a sensitive technique to distinguish the influence of major storm year input from the regular year input into the system. Major storms erode at the upper 3 dams and deposit sediment at Conowingo pond and at the present rate Conowingo pond will be filled in 50 years. Any sediment that enters the bay never leaves it. Questions by Davis, Zen, and Reinhardt.

     Ending the evening, Bob Ayuso of the USGS, Reston, talked to us about reversely zoned plutons in the Bottle Lake area of Maine. He concentrated his mineralogical and chemical studies on two plutons called the Whitney Cove and the Passadumkeag River. Although both appear to be reversely zoned, and Ayuso relied on fractionation of early crystallization products followed by remobilization to explain the igneous history of both, these two plutons have distinct differences. The Whitney Cove is missing the many xenoliths and presence of amphibole in its core that the Passadumkeag River has. Modal analyses of both show that quartz, plagioclase and K-spar are more abundant in the rim than core. Biotite in the core of both has a greater Fe/Fe+Mg ratio. Bulk chemistry shows the rim to be more siliceous. Ayuso feels the core has been re mobilized into the rim facies. Many questions showed that the audience was very concerned with Ayuso's "feelings" probably because he looks so much like Barry Manilow. Questions by Gill, Sutter, Bethke twice, Stifel, Barker, Jones, and Zen twice.

     Following the talks Louie Conant reprimanded the speakers (with the exception of Ayuso so as not to hurt his feelings) for the inappropriate use of slides with numerical tables. Gill reprimanded Conant for reprimanding the speakers. Finally President Toulmin interrupted and said he hoped all future speakers, particularly E-an Zen, were listening.

     Attendance was 76 with 171 women. My spring survey proves that the when total attendance goes down, the percentage of women in the audience goes up. Perhaps by the fall we will know what this means. Beer donations totaled $18.

     [signed Peter T. Lyttle]

     Meeting Secretary

 

Geological Society of Washington

26 May 1982

     The 1096th meeting of the Society was called to order by President Toulmin at 8:01 p.m. In spite of some very choppy prose the minutes were read and approved. The following guests were introduced: Barney Burger, John Ferry, George Gunstasakigus (?), Peter Zeitler, Tom Schmidt, Lincoln Hollister, Sara Hollister (who was still lingering over coffee in the dining room), and Kitty Reid.

     E-an Zen announced to the Society that a Russian earth scientist is being held prisoner in a work camp in Russia and asked for signatures on a petition to help free the man.

     The first talk of the evening was by E-an Zen, USGS, Reston. Zen's talk, "Are there really exotic terranes in the northern Appalachians? - or, games grown-ups play," concluded that all rocks east of a line of ultra mafic rocks that Zen called ophiolites are exotic. Zen used a number of criteria, including lithologic differences, evidences of plate margin processes, the presence of ultramafic rocks (which may be ophiolites); and magnetic data, to show that first the Merrimack terrane, then Avalonia were plastered onto the North American craton. He suggested that exotic terranes may be delineated using a combination of trace element geochemistry and fossil signatures. However, he did not address the problem of how to persuade geochemists and paleontologists to work together. Zen also suggested that exotic terranes can be useful in metallogenic studies. Questions by Hatch, Pavlides, Rankin, Stewart (who was upset that his favorite formations were not mentioned), Slack and Lipin. Even some long-time Society members could not recall the last time the list of questioners did not include Zen.

     The next talk was by Hans Nelson, USGS, Reston on "Patterns of deep-sea fan sedimentation". Nelson, using a split-screen technique, showed that small basins have definite, restricted channels with turbidites seaward of the fans. Whereas large basins have less well-defined chutes and thick sand in the most distal parts of the system. Nelson also demonstrated that Middle basins are intermediate between small and large basins: hence the term middle basin. Questions by some guy, and Towe, who thought Nelson had muddied the waters.

     The final talk of the evening was by Linc Hollister, Princeton University, on "Metamorphic evidence for rapid uplift (2 mm/yr) of the Coastal Gneiss Complex, British Columbia". Hollister showed andalusite-sillimanite-K-feldspar-muscovite-quartz veins cutting the sillimanite-cordierite gneiss and concluded that the rocks had experienced pressures and temperatures of 5 kb and 750°C to about 2.5 kb and 550°C. The higher P-T occurred at 14 my and the lower P-T was about 6 m y ago. Thus the Coastal Gneiss Complex hurtled 30 km upward in 8 my. Fluid inclusion and isotopic dating support Hollister's ideas, sort of. Questions by Robertson, Some Guy (different from the some guy in the previous talk), Arth, and Taylor. This marks the first meeting since 1963 at which no questions were asked by Zen.

     The meeting adjourned at 10:02 p.m. Attendance was 100.

     Respectfully submitted,

     Bruce Lipin,

     Secretary-of-Last-Resort

 

Geological Society of Washington

22 September 1982

     The 1097th meeting of the Society was called to order by President Toulmin at 8:00 p.m. The minutes of the 1096th meeting were read and approved. Al Rubin, K. Yanai, Dr. Almohandis, Giva Sadani, Mr. Goo, Leann Weyburg (who has since become Mrs. Daniel Milton), and William Wura were all introduced as guests. President Toulmin announced the deaths of three former GSW members and the Secretary read the names of 33 newly elected members. Field trip announcements of past and future trips were made. Wright Horton, Lou Pavlides' new alter ego and locum tenens, announced Lou Pavlides' upcoming November 6 field trip. Later Pavlides got even for not being allowed to talk by giving an informal communication. An announcement. was made that the basket for collecting beer money will no longer be put out and that in the future any contributions members would like to make can be in the form of tax deductible contributions or cash passed directly to the Treasurer, Bob Tilling.

     The first of two informal communications was presented by Lou Pavlides of the USGS, Reston. He and several co-workers have discovered that the Mountain Run fault zone of northern Virginia, which marks the boundary between the Piedmont and Blue Ridge provinces, contains faults of several ages, the most interesting being a young set of low angle thrust faults that bring saprolitized Piedmont mylonite against an unconsolidated mud flow deceived from the highly weathered Catoctin Formation of the Blue Ridge province. Other structures in the same exposure were so complex that Pavlides didn't have time to discuss the interpretations of the 45 geologists he has taken to view the evidence. When President Toulmin's new watch started to play a song suggesting that Lou's time was up, Pavlides asked whether the Good Humor Man just arrived.

     The second informal communication was presented by E-an Zen of the USGS, Reston, who used up the first minute of his time presenting the Society's teddy bear a jar of honey. Claiming that he did not want to make a mountain out of a mole hill, he proceeded to discuss strange earth filled tube-like structures found just above timberline on mountains out West. Edwin Way Teale suggested these things were the work of gophers and others felt the culprits to be moles. Zen suggested both camps were wrong and felt they are mini-eskers formed by melting water at the base of the snow pack. He also referred to these things as TMM which he hoped would draw some questions from the audience. When this failed he informed us this stood for Toulmin Memorial Mole. Questions by Robertson, Smith, Lipin, Towe, Appleman.

     The first scheduled talk of the evening was given by Steven Macko of the Geophysical Lab. He discussed the use of stable nitrogen isotopes as tracers of organic geochemical processes. The audience was impressed by the fact that Macko was talking about differences in values measured on the delta scale to the 6th and 7th decimal places. Although important nitrogen reservoirs mentioned where nitrogen is the limiting nutrient include seawater, marine plants, marine animals, marine sediments, and the atmosphere, Macko concentrated on the flow of organic matter in marine sediments, specifically on the identification of sources, and how marine and terrestrial sources mix. He argued that the origin of organic matter and the methods of mixing can be distinguished by using stable nitrogen isotopes, pointing out that the isotopic composition of nitrogen in coal is very similar to that in the original peat. One of Macko's study areas is where the Sheepscot River Estuary dumps a lot of terrestrial material in the Gulf of Maine. Another area was Baffin Bay, Texas where salt flats are flooded in the spring and desiccated in the summer. Additional complications occur when hurricanes cause large tidal surges in the sum mer. Questions by Sellers, Helz twice, Sato twice, Towe twice and Hatcher.

     The second talk of the evening was given by the ever-more-familiar Ellis Yochelson of the USGS, Washington, D.C. Giving his second talk of the year he returned to his favorite topic--his hero Charles Walcott, the 21st employee of the USGS This episode detailed Walcott's work in the Harding Sandstone and Freemont Limestone of Canyon, Colorado where he became interested in establishing the ancient of fishes. Establishing that Walcott worked faster than the average geologist, Walcott's find of Ordovician fossils held the record for the oldest until John Repetski came up with the Cambrian one he reported on to the Society a couple years ago. Geologists of the time ignored Walcott's work for at least 25 years, which Ellis suggested is a good way to become director of the USGS Another conclusion which I can't remember how it fit into the story is that German professors are dumb. Questions by Ryan, Mary-Hill French.

     The final excellent talk of the evening was given by Peter Lyttle of the USGS, Reston, who discussed whether the Octoraro Phyllite found in the South Valley Hills around Bryn Mawr could be equivalent to some of the rocks in the high Taconic slices of New England. He decided much to everyone's surprise that yes they could. Lyttle began his talk with a limerick dedicated to former Secretary Dave Wones and ended his talk with a slide of his hero Florence Bascom. Questions by Rankin and Robertson.

     The meeting adjourned at 9:50 p.m. Attendance was 105 with 20% of those present women. This percentage has increased steadily for the last 4 out of five meeting whatever that means.

     Respectfully submitted,

     Peter Lyttle

     Meetings Secretary

 

Geological Society of Washington

13 October 1982

     President Toulmin brought the 1098th meeting of the Society to order at 8:08 p. m. The minutes of the 1097th meeting were read and approved. Four guests were introduced: Dr. Chen Wan Chen) Dr. Charles Cunningham, Tom Holzer, and Fred Barker. Fred Barker now holds the record for being introduced to the Society the most times. The Secretary announced that nine new members had been elected by Council that afternoon and the President announced the death of Irving Breger. Wright Horton and Lou Pavlides discussed the upcoming GSW field trip and asked people to continue to sign up for it. President Toulmin announced the slate of officers for 1983.

     Eric Force began the evening with an informal communication that suggested that throughout geologic history anoxic events in the oceans, magnetic quiet zones, and fast spreading rates all occurred at roughly the same intervals. And because spreading rates can be related to transgressions, which in turn can be related to a higher albedo for the surface of the earth, it all goes to show that activity in the earth's core may have a direct, if tortuous, relation to the Earth's climate. Force stopped short of suggesting that the USGS start hiring deep earth geophysicists and high pressure experimentalists for its Climate Program.

     The first talk of evening was presented by past President and present Program Chairman, Tom Dutro of the USGS, Washington, D.C. Even though he attempted to show that the new 132 page North American stratigraphic code has something for everyone, the main message received by many in the audience is that we would be better off ignoring it. An example of one of the many helpful suggestions is igneous intrusions of old are now lithodemes. Questions by Kinney, Force, Zen, Hanshaw and Hanshaw. That sounds like the name of a law firm.

     The second talk of the evening was presented by Werner Schreyer of Ruhr Universitet Bochum. The next 30 minutes proved beyond any shadow of a doubt that Professor Scheyer is a gentleman and an imperturbable speaker. He not only put up with a considerable wait for many of his slides, he also responded with grace to an unfortunate, "insert foot-in-mouth" comment about German professors uttered by the Society's secretary. Schreyer presented evidence bearing on the origin of the Vredefort dome in South Africa and came to the conclusion that it was formed by an internal explosion and not simply the result of a meteorite impact. The Vredefort dome is a 100 km diameter cryptoexplosive structure occurring in 2.8 b.y. old craton and is rim med by sediments 12 to 16 km thick. The age of the doming is 2 b.y. ago. Schreyer suggests that a magma diapir formed at the base of the crust which contact metamorphosed the overlying sediments. CO2 began to concentrate and build up until there was a huge gas explosion which produced the shock metamorphic effects, followed by a complex recrystallization and diaplectic history. To support this story he pointed out that the fluid inclusions in quartz (which can contain up to 10 % inclusions) are very dense and need an overburden of 7 km of sediment. Not your typical case if it were an impact structure. Questions by Arth, Hazleton, Milton, some woman, and Fudali (three times).

     The final talk of the night was given by Dave Brew of the USGS, Menlo Park. Wanting to be in the forefront of geology he attempted to describe the rocks he has been mapping in Alaska with many of the names from the new North American stratigraphic code that Tom Dutro so helpfully provided earlier in the evening. Taking us on an east-west traverse across the coastal plutonic­-metamorphic complex in northern southeastern Alaska, Brew suggested that all of the rocks from the east edge of Wrangellia eastward to the west edge of the Cash Creek terrane, are all part of the Alexander plate and not a number of different suspect terranes. Even though the central and eastern part of Alexander plate exhibits a higher grade of metamorphism and is more highly deformed, he felt that the evidence for having a number of different protoliths for the rocks of the Alexander terrane was insufficient to warrant the complex tectono­stratigraphic breakdown of some other workers. Questions by Force, Robertson, and Zen.

     Attendance was only 88 breaking the trend of increasing attendance throughout the fall. This was paralleled by a slight drop in the percentage of women attending from 20 to 18 %. The meeting adjourned at 10:03 p.m.

     Respectfully submitted,

     Peter Lyttle, Secretary

 

Geological Society of Washington

27 October 1982

     The 1099th meeting of the Society was called to order by President Toulmin at 8:14 p. m. The minutes of the 1098th meeting were read, corrected and approved. Three guests were introduced: Ed Duke, Julie Morris, and Maureen Steiner. Announcements were made on how to join the Society and about the Pavlides field trip which finally took place last Saturday the 6th. President Toulmin promised to do something about the meetings announcements arriving so late for so many members.

     Josh Tracey, reacting to editorial comments made by the Secretary, rose to defend the honor of the New Stratigraphic Code which was formally adopted at the GSA meeting in New Orleans. 

     Klaus Shultz of the USGS, Reston gave the first talk of the evening on high Fe komatiites from the 100 km long belt of the 2.5 b.y. old Vermillion greenstones in Minnesota. The basic message seemed to be that if these ultrabasic lavas in Minnesota can be called komatiites, then the criteria normally used for defining these rocks will have to be modified considerably. The Vermillion komatiites are lower in Al and higher in Ti and Fe than most others. They are also found at the top of the pile of associated rocks- and not at the bottom as usual. Shultz called on the necessity of having garnets crystallizing in the parent magma to account for the unusually low Al/Ti ratios and the depletion in the heavy REE. Questions by Wasserburg, Robertson, Towe, Milton and Peck.

     While the 2nd talk of the evening was presented by Gerry Wasserburg of Cal Tech, his slides were skillfully arranged by Robin Brett. Wasserburg used the ratio of neodymium 143 to 144 to illustrate how the waters of the earth's oceans mix. Since the half life of the isotope is 106 aeons, considerably longer than the average oceanic process, he felt it fair to assume that any change in the ratio reflected a mixing process of different sources of the isotope rather than decay.  From that point on I must confess I became a little confused so the rest of this synopsis may suffer.  The ratio of 143Nd/144Nd has increased slightly from the chondritic unfractionated reservoir values 4.5 aeons ago to the present. This curve can be deflected by additions from HREE-enriched ocean basalts or LREE­ enriched continental crust. Since 70 % of the world's rain water drains into the Atlantic, it presumably has a lower 143Nd/144Nd ratio than Pacific oceans waters. The Drake Passage acts as a mixing valve for the 2 oceans. So even though theoretically one could drain the Pacific Ocean into the Atlantic (whatever that means) in 150 years, the fact that most of the Pacific Ocean water going into the Atlantic is already Atlantic ocean water means it would take much longer. Even though I am not positive he said that, I am sure he said one can not get an overdose of REE by drinking sea water. Questions by Peck, Lipin, Helz, Towe, and Whitaker. Brett had nothing to say.

     In the 3rd talk of the night, John Sutter of the USGS, Reston, discussed the confusing state of the absolute time scale and one way in which he and Mick Kunk are trying to straighten it out. One of the hardest problems is getting suitable samples to date. They chose to sample the mid-continent Middle Ordovician bentonite in Alabama, Tennessee, and Kentucky where the volcanic unit is interbedded with fossiliferous sediments. Sutter emphasized that for most dating techniques, even if you accurately determine the decay constant and can measure the parent/daughter rations extremely accurately you can still have major problems if the isotopic system has been open at any time. He employed the 40Ar/39Ar technique and dated biotites from the bentonite. All three samples were sandwiched between sediments containing conodonts of mid-continent zone 8 or Rocklandian age. Using this technique, he was able to get excellent plateau ages that had incredible precision and very small error ranges and that agreed beautifully with the fossil ages. In contrast all other dating techniques used on these same rocks over the years gave a much larger range of possible ages that were generally younger than the values Sutter obtained. Interestingly, none of the other techniques gave older ages. Questions by Arth, Towe, and Wasserburg. By this time Brett and Lipin had retired to the back of the room to be near the beer. Lipin claimed however that it was Fred Simon and not them making all the noise banging glasses during the talk.

     Attendance was 98, 21 % women. The meeting adjourned at 9:58 p.m.

     Respectfully submitted,

     Peter T. Lyttle,

     Meetings Secretary

 

Geological Society of Washington

10 November 1982

     The 1100th meeting of the Society was called to order by President Toulmin at 8:03 p.m. The minutes for the 1099th meeting were read and approved. Three guests were introduced: Bob McDowell, Kathy Hanger, and Martha Hayes. The Secretary read the names of 13 new members elected by Council that afternoon. The field trip lead by Lou Pavlides was reported as a great success. It was also reported that G S W will be a co-sponsor of an international meeting for fossil cnidariar experts to be held next year in Washington.

     Tom Ager of the USGS, Reston gave the first talk of the evening on the history of Alaskan vegetation and climate over the last 35,000 years. Using the framework known from present day vegetation in Alaska, Ager divided the state into three types of vegetation: tundra and barrens, interior boreal forest containing mostly spruces, poplars, and birches, and the coastal forest containing hemlock and citrus trees. By looking at pollen, ostrocodes, diatoms, fossil vertebrates and working it in with the volcanic ash record, Ager presented his reconstructions. Some of the lakes where he cored the bottom sediments actually give records going back 16,000 to 35,000 years. For much of southern Alaska Ager's reconstructed history shows that between 32,000 and 34,000 years ago forest tundra dominated, then between 14,000 and 32,000 years ago arctic steppe formed wiping out the spruce, then between 10,000 and 14,000 years ago shrub tundra formed and finally around 9,000 years ago spruce came marching back in from Canada. Questions by Erickson, Rubin (2), Behrensmeyer, Cronin, Hewitt, Taylor, Schaeffer, and some guy.

     Sam Patterson of the USGS, Reston, presented the 2nd talk on everything you wanted to know and then some about aluminum. Noting that even though Al is the 2nd most used metal in the U.S., the Al industry is in hard times. The only product made with A1 with production increasing is beer cans. Patterson gave a history of the Al industry noting that Carl Bayer first extracted alumina from bauxite in 1884 and soon thereafter Charles Hall of Oberlin made the first metallic Al by the electrolytic process. Then someone went and put an Al pyramid on the Washington monument. In the U. S., the Beyer process derives Al from gibbsite, while in Europe the main source mineral is boehmite. There is one plant in Greece that uses diaspore. Questions by Erickson, Lipin, Hewitt. In response to Hewitt's question Patterson gave the longest answer recorded by this Secretary. During this 13 minute period there was unrivalled activity at the beer keg. I counted 27 people back there at one point.

     The last talk of the night was given by Joe Hazel of the USGS, Reston. He discussed a technique called graphic correlation and used the Cretaceous time scale as a test case. If you have a computer available this technique allows a stratigrapher to compare numerous sections, all incomplete in different ways, and come up adjusted composite sections which are much more complete. As more sections become available, the composite sections can be extended and refined. Hazel's use of this technique needs good radio metric ages to fit into the relative ages of the model section. Once the section is calibrated you can then work backwards from some linear relationships and get real ages for the relative datums. In the Cretaceous this allowed him to find very precise age ranges for particular formations. Questions by Hewitt, Whitaker, Hatch, and Robertson.

     Since this was the 1100th meeting, I thought I'd look back 100 meetings, and see how attendance and other things compared. That didn't work since it wouldn't be fair to compare this meeting with the gala event when 350 people showed up. So I went back another 100 meetings to the 900th meeting on December 13, 1967. It turned out to coincide with the 75th annual meeting when Mike Fleischer gave his Presidential address to an audience of 224. That was the meeting when dues for active members were raised from $3 to $5 and when Ben Morgan was elected to membership in the Society.

     Attendance at the 1100th meeting was 100 (24% women). The meeting adjourned at 9:47.

     Respectfully submitted,

     Peter T. Lyttle, Secretary

 

Geological Society of Washington

Minutes for the 1101st meeting

     The 1101 meeting of the Society was called to order by President Toulmin at 8:22 pm December 8, 1982. The minutes of the 1100 meeting were read and approved. Seven guests were introduced, although it took two tries to get one of the guests introduced even with various helpful hints from the audience as to what the fellow's name was. Four new members were introduced including a Shanghaid secretary, who failed to say "no" at the critical moment. The first vice president of the Society, soon to be president, Gene Robertson introduced President Toulmin soon to be past President, who then presented the presidental address entitled "Mountains, Meadows and Magmas in Central Colorado".

     The talk began with a comparison between the real Mt. Aetna and its Colorado counterfeit and some vague reference was made about the possibility of crystal settling being the thing that attracted his initial interest to this part of Colorado. This cover was blown, however, by the first of many scenery shots that quite clearly exposed the real reason for the choice of field area.

     The oldest rocks in the area are probable pre-Cambrian gneisses whose K-Ar dates have been reset to early Mesozoic age. The Mt. Princeton quartz monzonite was emplaced, with the Mt. Pomeroy being interpreted as an early border phase. This rock was altered to what was referred to as "Christmas rock" because of the nice red and green spots in it. (Toulmin prided himself on his attempt to eliminate technical jargon and geochemical triangular diagrams from his talk so that even friends of the Cnideria could follow it. Still he could not resist showing 2 or 3 suitably unreadable triangles.)

     Overlying a weathered Mt. Princeton surface a spectacular volcanic unit, the Calico Volcanics, was deposited. It contains andesite lava flows, lahars and agglomerates. The next unit, the Swanee Volcanics represent a major caldera collapse phase with mega-breccia.

     After these volcanic episodes, two faults, one N/S and the other NE/SW apparently down-dropped a large block containing the roof pendant and volcanic caldera units and the older Mt. Princeton group. Thus these were protected from erosion and are now found only between these faults.

     The Mt. Aetna quartz monzonite porphyry was then intruded, with magma flowing into these faults forming prominent dikes. Two younger intrusions are also present.

     How big was the Caldera represented by Swanee Volcanics? Toulman offered two choices, pretty small or real big. He favored the real big interpretation.

     Available age dates for the whole thing are in the range of 33-40 my, an embarrassingly short time to do all the intruding, extruding, uplifting and eroding that is required. This point was hurriedly passed over in order to address the question of where did the ejecta from Aetna go. It was proposed that some of it may be preserved to the east of the Rio Grande rift which is a later feature in the 39 mile volcanics.

     The talk was illustrated by many beautiful panoramic slides of the Colorado high country, marred only by the presence of several faceless geochemists, only one of whom was actually looking at the rocks.

     Toulman invoking his singular constitutional right to escape pesky questions, abruptly adjourned the meeting a 9:45. Protests were drowned by surge of humanity towards the beer keg. Attendance was 102.

     [signed T. O. Wright]

 

Geological Society of Washington

8 December 1982

     The 90th Annual Meeting was called to order after a short beer break following Pete Toulmin's Presidential Address. Marilyn Estep read the minutes of the 89th Annual Meeting, which were approved by the members. Peter Lyttle then gave the Annual Report of the Meetings Secretary complete with slides. After minor discussion these too were approved. Marilyn Estep came to the podium again to give the Annual Report of the Council Secretary. Nick Van Driel, substituting for the traveling Bob Tilling, reported on the finances of the Society. In summary, income was $9057.04, expenditures were $8383.47, with total assets equaling $12,081. This report was audited and approved by Bill Prinz. Mary Mrose performed her annual duties with her usual gusto and good humor and gave us the nitty-gritty of membership statistics. There are 651 active members, 226 corresponding, and 137 retired members. Having decided that she would step down as Membership Chairman, the Society honored Mary with a plaque and a long standing ovation.

     The awards committee, consisting of Rob Robinson and anonymous helpers, presented a summary of the year's best or at the very least, the most memorable talks. Honorable mention was made of talks by Yochelson, Malahoff, Marsh, Hatcher, Nelson, Shultz and Wasserburg. The Great Dane went to Jim Clark for his timely discussion of oil potential on the Falkland Islands. The 2nd best talk of the year with an award of $100 went to Dennis Stanford for his record length talk on "the antiquity of human population in North America"--a talk that spent most of its 60 minute length discussing how to butcher an elephant if a zoo happens to give you one. The best talk of the year was awarded the Bradley Prize of $200. This went to Werner Schreyer of Ruhr Universitet Bochum. His talk on the Vredefort dome appealed to and was understood by everyone--an unusual accomplishment.

     The Secret Bear Committee stepped forward in the guise of Kathy Krafft, substituting for Steve Huebner and Dan Milton. Putting her editorial capabilities to caustic use, she recalled the typically sophomoric humor of Lipin, Evenson, Force, Dutro, Pavlides and Hollister. In the end, she finally awarded this greatest of honors to Dave Stewart for his comment about paving Linc Hollister's map area with Harvard theses.

     The nominated slate of officers was elected unanimously.  Newly elected Robertson introduced the newly elected Council.  Toulmin transferred the teddy bear to Robertson marking the formal end of the year.

     Respectfully submitted,

     Peter T. Lyttle

     Meetings Secretary