GSW: 1991
MEETING MINUTES
MINUTES OF THE GEOLOGICAL SOCIETY OF
1207th Meeting, January 9, 1991
President Barton called
the meeting to order at 8:05 p.m. The minutes of the 1206th meeting were
approved after changing Brace Wardlaw's "respectively submitted" to
"respectfully submitted". Three guests were introduced: Gayle and
Jane McColloch of the West Virginia Geological Survey and Chuck Drevo,
As one his fast official
acts, President Barton tested the audience's alertness by introducing the first
speaker with the biographical background of the third speaker. The puzzled
audience immediately brought the error to the President's attention, and Bob
Fudali, Smithsonian Institution, was introduced with his background intact. In
his talk, "My summers on the South Polar Plateau: an overview of the U.S.
Antarctic Meteorite Program", Bob described the systematic collection of
meteorites on polar ice, an ongoing program since the discovery of meteorites
there in 1971. Hundreds of meteorites have been found along the
Roz Helz, USGS,
presented "What happens when mushes move? Observations from Kilauea Iki
lava lake. Her answer was based on
observations of textures from drill core KI79-1, the bottom of which bounced up
and down on its own due to backfilling by crystal-rich mush. Redrilling in the
hole revealed ferrodiabasic segregation veins, vertical olivine-rich pipes, and
crystal rich mush that moved up the borehole and segregated melt as it moved.
Roz documented textures showing melt spot formation and aggregation of
groundmass minerals around olivine; large and continuous melt channels wrap up
the side of drill core acting as chimneys that allow melt and vapor to rise,
moving up through crystalline mush. Melt spot formation and movement in a
partly crystalline mush may be a significant process by which melts segregate
and move through mushes. The talk lasted 20 minutes, followed by questions by
Stifel, Zen (3), one of which Hansen thought of also but Zen asked, Toulmin,
and
Ted Maxwell,
Smithsonian, concluded the program with "The surface of Venus: a report on
Magellan's new views". We were shown the dramatic improvement in
resolution of the Venutian surface features, such as recognition of 70km wide
impact craters with internal structures, volcanic features including collapse
craters, volcanic plains, and low relief ridges similar to graben and
compression-related features on the moon, faults, and perhaps even layered deposits.
Magellan images 27 to 40 km wide swaths, then stops and to transmits data back
to earth; in four months Magellan has returned more data than all other
planetary missions. Questions by Barton, Zen, and the speaker himself, who
asked how does one get the data, and answered by telling us that the primary
data will be released on CD Roms.
Attendance was 75±5 (the
uncertainty reflects the highly mobile nature of the crowd, particularly the
last few rows). The meeting was adjourned at 9:49 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF
1208th Meeting, January 23, 1991
President Barton called
the 1208th meeting of the Society to order at 8:04 p.m. The minutes of the
1207th meeting were read and approved. Six visitors were introduced: Mario
Jardine, Grace Haggetty, Heidi Cruz, Caroline Purdy, Tracy Schwarz, and Eirik
Krogstad. Seventeen newly elected members
were announced. President Barton announced the death of Preston Cloud. Treasurer
Fred Simon informed us that only 519 responses had been obtained out of 800
dues bill mailed. Fred then cheered us up by offering the "good news"
that many members who had paid made donations above and beyond their required
$14. John Slack presented an informal communication, on the first documented
occurrence of berthierine in volcanogenic massive sulfide deposits. Chlorite is
commonly present in the mineral assemblages of these deposits and studies have
examined the chlorite composition, namely Fe/Mg ratios, as an indicator of
fluid chemistry. John probed chlorites from the Kidd Creek, Ontario deposit and
found both iron-rich and iron-poor chlorites in the same deposit. His x-ray
study showed that the iron- rich chlorites are really berthierine, a 7 ÅFe-Al
serpentine which cannot be uniquely identified by probe, but can be identified
by the lack of 14 Å chlorite peak in an x-ray diffraction pattern. Thus, much
of what has been previously reported as chlorite in volcanogenic massive
sulfide deposits may actually be berthierine. Questions by Robertson, Toulmin,
Zen, and Hammarstrom.
George Helz,
Jeff Ryan, DTM, spoke on
"Boron and beryllium in Kurile arc lavas, or, how melts are made in a
convergent margin. Jeff used the geochemistry of Be and B in samples across the Kurile island
arc to examine mechanisms of addition of subducted components to mantle. B is a
sensitive tracer of slab addition whereas Be and other elements are more sensitive
to partial melting. The Kurile arc rocks have high B/Be ratios at the front of
the arc; ratios drop off and look like uncontaminated mantle at the rear arc.
Rear arc samples are higher in K and Ba than front arc samples and are
characteristic of derivation from smaller degrees of partial melting. Melting
alone cannot account for the B/Be behavior, and there appears to be a causal
relationship between slab addition and extent of melting. The talk ran a mere
11 seconds over 20 minutes. Questions by Dan Milton and Paul Barton.
E-an Zen,
President Barton
adjourned the crowd of 96 at 9:49 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF
1209th Meeting, February 6, 1991
Second Vice President
Phil Candela called the 1209th meeting of the Society to order at 8:03 p.m..
President Paul Barton and First Vice President Steve Huebner were both out of
town resulting in the unusual (possibly unprecedented in the annals of the
Society?) situation wherein the Second Vice President actually had something to
do. The minutes of the 1208th meeting were read and approved. Visitors Tom
Ahlbrandt and Peter Warwick were introduced and three new members were
announced: Mario Giaramita, Smithsonian Department of Mineral Sciences; Harvey
Beaulieu, Oosterbaan Assoc.; and Peter Warwick, U.S.G.S. Branch of Coal
Geology. Acting president Candela announced the death of longtime member and
past president Walter White. Laurel Muehlhausen made two announcements on behalf
of AWG. Laurel told us about an upcoming dinner talk by Dr. Alexandra Tolstoy
entitled "Underwater acoustics and the hunt for Red October" which
will take place on Tuesday, April 2 at 7 p.m, at George Mason University and
she also announced that the Penelope Hanshaw Scholarship, an award presented by
the Potomac Area Chapter of AWG to an outstanding local female geoscience
major, is accepting donations and nominations.
Patricia J. Loferski,
U.S.G.S., presented the fast talk of the evening, entitled "Evidence for
liquid immiscibility in the Stillwater Complex from melt inclusions in
plagioclase". Patti showed us that melt inclusions can provide unique petrographic
information on Stillwater anorthosites and insights about the nature of parent
liquids. Melt inclusions occur in many plutonic and volcanic rocks, but they
are difficult to identify in plutonic rocks where they have crystallized as
mineral inclusions - in volcanics they are more obvious because they are
preserved as glass. The typical anorthosite has a cumulate texture with a framework
of plagioclase cemented by intercumulus pyroxene, ilmenite, and apatite. Melt
inclusions in plagioclase in anorthosite are rounded, 40 to 100 micron in diameter,
clinopyroxene grains that enclose apatite and ilmenite. The inclusions have
constant mineralogy, modal proportions, and are randomly distributed - all of
which suggest that they probably crystallized from a liquid. This liquid was
not the parent of the anorthosite, nor was it trapped residual liquid, but
rather a liquid having a peculiar bulk composition enriched in REE, Ca, Ti, Mg,
P, Zr, and Fe, a suite of elements that partitioned into a depolymerized mafic
immiscible liquid that exsolved as droplets that were trapped in plagioclase
and subsequently crystallized to the observed mineral assemblage. The talk
lasted 20 minutes and 30 seconds. Questions by Dan Milton, George Helz, Bill
Greenwood (2), Pete Toulmin, Roz Helz, Brooks Hansen, and Bruce Lipin.
Dan Appleman,
Smithsonian, gave us an informative account of the life of "James Dwight
Dana, geologist volcanologist, and mineralogist". We learned that contrary
to popular belief, Dana was more of a volcanologist than mineralogist. Dana
sent his eyewitness account of a Vesuvius eruption, which he saw because he was
teaching math for the Navy on a Mediterranean cruise, to his Yale professor who
published it in AJS. In 1837 he published the 1st edition of the System of
Mineralogy based on a system similar to that used by biologists rather than on
chemistry. The book brought him renown and in 1838 he joined an expedition to
chart unknown seas of interest to the U.S., which enabled him to conduct
studies throughout the Pacific, including Australia, Fiji, Hawaii, and the
Cascades. These studies included geologic mapping, detailed geologic
observations of volcanoes noting differences between shield volcanoes and
cinder cones, alignment and age progressions of volcanic islands, fossil descriptions,
observation of landslides, and correct interpretation of the origin of atolls
by growth around volcanoes followed by subsidence - a concept that Darwin
apparently could not grasp. Dana's map synthesis of Pacific geology looks a lot
like a recent plate tectonic map of the Pacific, and his contributions, all published
in volume 10 of the expedition constitute a veritable textbook of Pacific
geology. The talk ran a timely 19 minutes and 50 seconds. Questions by Lipin
and Galvin.
The program concluded
with Thomas S. Ahlbrandt, U.S.G.S., speaking on "Sand seas of the midcontinent:
their chronology and implications for desertification". Many of us (well,
I and at least one other person I spoke to) Were surprised to learn of the
extent of these eolion deposits, which cover about 100,000 km2 in
Nebraska, eastern Colorado, Kansas, Wyoming, Oklahoma, and Texas. Tom's talk concentrated
on the Wyoming dunes where sand transport studies were used to measure drift
rates and belts of dune migration were identified. Some of the highest wind energy
in the world is recorded in SW Wyoming dunes, and these terranes are
potentially susceptible to climactic changes. Carbon 14 dating of dune artifacts
identified 4 major pulses of eolian activity in the last 11,000 years, the most
recent about 1,000 years ago. In the Nebraska Sand Hills, sprinklers are emplaced
for stabilization, but dune blow-outs can interfere with roads and have profound
effects on agriculture. Wind erosion in the area exceeds water erosion
affecting soils, 97% of the area is highly erodable, and 66 % of the high
plains aquifers are in the Sand Hills area. The talk ran a 17 second tad over
20 minutes. Questions by Sato, Buster, Houser, Rye, Kinney, Krohn, and Bruce
Lipin, in his third (yes Bruce, we're counting) question of the evening, who
simply could not resist asking the origin of the name of the Killpecker Dunes
although the speaker had previously touched upon this delicate subject while
Bruce was no doubt busy with chairmanly duties in the back of the room.
The meeting, attended by
76±3, was adjourned at 9:39 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1210th Meeting, February 27, 1991
President Paul Barton
called the meeting to order at 8:01 p.m.. The minutes of the 1209th meeting
were read; and the secretary's comment on the possibly unprecedented situation
of having the second vice president run the previous meeting was discussed at
length by Dutro, Lipin, and Zen - who all remembered various past occasions
when our chain-of-command had been put to even more stringent tests. The
secretary will check the historical records of the Society to get this straight
as soon as the Minutes book is passed on by the previous secretary, which I
understand will probably be about next December, if tradition holds. The
minutes were not exactly formally amended, and I can't remember if they were formally
approved, although I do remember Paul saying "That's not in Roberts
anywhere".
Visitors Doug Crowe, an
NRC postdoc; Paul Stone, U.S.G.S. Office of Regional Geology; and Herman
Roberson, NSF were introduced. Judy Ehlen announced the start of science fair
season and called for volunteer judges. There were no informal communications.
Scheduled first speaker
Peter McCabe was bogged down with an illness, so we did not get to hear about
being "bogged down in the mire - organic control on the architecture of
shoreface deposits. Howard Evans, U.S.G.S., very graciously filled in at the
last minute, and spoke on "Crystal chemical studies of iodate minerals in
the evaporite deposits of northern Chile". Howard described his collaborative
studies with George Erickson and Mary Mrose on the strange minerals that occur
in evaporite settings, called salars, in northern Chile. This is one of the
driest regions in the world, and salars are essentially nitrate deposits
created by rain effluent from the Andes into basins. The main mineral of these
deposits is soda nitre, with lesser amounts of halides, gypsum, sulfates such
as thenardite, iodates, chromates, and borates. Howard described the
difficulties of solving the crystal structure of hectorfloresite, a
sodium-iodate-sulfate mineral that was collected from the sodium sulfate zone
that overlies the nitrate zone in one of the salars. The hexagonal prisms
presented some problems because the assumption of a twinned monoclinic cell
could not reconcile the prominent hexagonal lattice with extra spots on the
precession photos. It turned out that a monoclinic cell could he isolated from
the complex twin and the structure was solved by projecting along the
pseudohexagonal axis for floresite. At high temperatures, by which Howard meant
above 30ºC, one of every 5 SO4 groups of
the sodium sulfate floresite is replaced by iodate, resulting in the disordered
structure of hectorfloresite. The talk ran a precise 20 minutes. Questions by
Peggy Appleman, Tom Haring, Ken Towe, Bill Back, E-an Zen, and 2 by Paul Barton.
The second speaker was
Dan Miller of the American Heritage Foundation, who talked about "The
Anaconda Collection: 90 years of geological, geophysical, and geochemical data
and how you can gain access". Dan described the history of the Anaconda
Mining Company and the influence of Reno Sales, its chief geologist for 50
years, on the organization of their worldwide exploration efforts. Sales set rigorous
policies for record keeping, which has made it easy to index the entire
Anaconda records collection on computer. The state of Wyoming acquired the
collection from ARCO, the company that bought out and then dissolved Anaconda.
The University of Wyoming houses the Anaconda Geological Document Collection as
well as other geologic and petroleum data collections, and makes the data
available to industry and other interested parties by a "country club
membership" type of system. The collection consists of 54 tons of information
on 110 countries. The talk ran 20 minutes. Questions by Lipin, Towe, Simon,
former Anaconda employee Doug Crowe, Wardlaw, Back, Zen, and Houser.
Bob Seal, U.S.G.S.,
concluded the program with a talk on "A fluid inclusion perspective on
oxygen isotope exchange between quartz and water, and some geologic
applications". Bob examined the problems encountered in using kinetic rate
constants based on experiments al temperatures greater than 350°C to
extrapolate isotope fractionation factors to lower temperatures. Bob analysed O
and H in fluid inclusions in quartz from 14 samples ranging in age from 10
million years to 2.5 billion years. Bob examined the salinity-temperature-time
relations of his data and found that the oldest, hottest, and most saline
samples had exchanged the most. His results show the low temperatures rate constants
normally used are too fast, and these data can be used to revise exchange
constants. Two applications of oxygen isotope studies that are affected by this
study are the use of d18O from sediments to study quartz
provenance and the use of the isotopic composition of marine cherts as
paleotemperature indicators. Published rates say that a chert sitting at 25°C
will be reset in a year; the revised rates from this study show that it takes
close to 100 million years to entirely reset the system, so to use chert as a paleotemperature
indicator, you have to know the diagenetic history. Questions by Herman (1
didn't get a last name) of NSF, George Helz, Mike Palin, Ken Towe, and Sylvia
Nersbacher.
President Barton adjourned the somewhat sparse turnout of 59 members
at 9:46 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1211th Meeting, March 13, 1991
President Barton called
the meeting to order at 8:06 p.m. Minutes of the previous meeting were approved
and one visitor, Jack Credlin, NRC, was introduced. The election of four new members
was announced: Herman Roberson, Karen Prestergaard, Tom Ahlbrandt, and Bill
Luth. Judy Ehlen elevated her previous "request" for science fair
judges to "begging" status and announced that she was "desperate"
for judges for April 13 and 23. Then we had another visitor announced, Dr. Z.
Chen, who is at the Smithsonian for two years and has something to do with the
Yangtze delta. Our slightly disorderly meeting, which was attended by a daring
65 devotees who braved the threat of a spring snow, continued with Jeff
Grossman's update on the 1993 centennial of the Society.
Gene Robertson is the
chairperson of the centennial committee and special meetings are being planned,
as well as publication of a volume describing the history of the society and
biographies of our founders. Jeff alerted us to the mystery of the missing
minutes, which he described as a "Rosemary Woods" gap in the annals
of the Society for the years 1904 to 1925. During this time, abstracts of talks
were published by the Washington Academy of Science and by Science, but the
actual minutes recorded by the secretary (which we all know truly capture the
spirit of the organization) are unavailable. The committee needs help
organizing the archives of the Society and setting the record straight and
seeks volunteers.
Lynn Walter, University
of Michigan, spoke for 20 minutes and 10 seconds on "Syndepositional
dissolution and recrystallization of modern carbonates: Adventures in Club
Mud". Lynn pointed out that there is a big gap in our knowledge of
sedimentary geochemistry between modem reefs and ancient rock environments.
Lynn works in the Florida Keys (where she is better known as the "mud
queen") bemuse the area is alive - a shallow water environment
characterized by rapid production of sediments, rapid burrowing of the upper 60
cm of sediments by shrimp, and reactive sediments. Lynn focused on the question
of the whether or not reactive sediments in such environments are dissolving
and looked to pore water chemistry for evidence. Organic matter decay produces
CO2, the saturation state of pore water is lowered with respect to
CO2, oxygen is lost, but burrowing shrimp stir the sediments enough
that SO4 reduction is not significant. Lynn's modeling shows that
about 400 micromoles of CO3 per cm per yr are dissolving. The point
is that the whole carbonate production of the biota is much greater than what
is preserved and the difference is from dissolution. Carbon isotope data for carbonate
sediments from Buzzard's Bay and from Florida Bay never get very negative
despite organic decay suggesting that there could be buffering as well as
dissolution. Incubation experiments on sediments show that both carbon and
oxygen isotopes evolve to heavier values relative to living specimens.
Questions by Sorensen, Shanks, Prestegaard, and Barton.
Pat Shanks, U.S.G.S.,
was the second speaker with a talk entitled "Alvin dives, black smokers,
and sea-floor massive sulfide deposits." There are now about 30 known sea
floor hydrothermal vents. Pat concentrated on his work on the Escanaba Trough deposit
on S. Gorda Ridge, just north of the Mendocino fracture zone off the Oregon
coast. This deposit lies within the EEZ and has been studied by the U.S.G.S.
since 1985. Pat described a 1 km long hill on the sea floor on top of a
volcanic edifice that is nearly continuously covered with sulfides and includes
three vents - a 218° white smoker, a 108° vent, and a 18° vent. Estimates of
the size of this deposit range from 500,000 tons of sulfides to 10 million
tons, depending on the thickness of the deposit, and if the three areas are connected
they could represent as much as 100 million tons of ore, so not all sea floor deposits
are tiny. Pat then asked what these would look like in the rock record, and
showed that the geologic ingredients and scale of the Ducktown deposit are
similar to the deposits of the Escanaba Trough, including the pyrrhotite-rich
character of the ores, and sulfur isotopes. The presence of sediments in the
stratigraphic column has a decided effect on trapping sulfides and controlling
the redox state of these deposits. The talk ran a slightly long 21 minutes and
13 seconds. Questions by Hammarstrom, Palin, Brett, George Helz, Rye, Hemley,
and Burke.
Gordon Brown of Stanford
spoke on "Mineral surfaces and interfaces, the next frontier in
geochemistry". Gordon defined the terms sorption, precipitate, and adsorption
and showed us how new atomic scale techniques can be used to study reaction
mechanisms at surfaces. We saw images of hematite from a scanning tunneling
micro- scope showing nanometer scale lumps and defects that represent reactive
surfaces and images of galena in water where apparent pits may be defects where
sulfate formed. Atomic force microscope images are produced by scanning across
surfaces with a laser that measures deflections from a plane or surface, and
this technique can be used to study surfaces in water, air, or a vacuum.
Scanning tunneling spectroscopy can identify the type of atom on a surface. The
talk ran a long 22 minutes and 56 seconds. Questions by Walter, Barton,
Toulmin, Nersbacher, and Peggy Appleman.
The meeting was
adjourned at 9:50 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1212th Meeting, March 27, 1991
President Barton called
the meeting to order at 8:01 p.m. Four visitors were introduced: Grace
Haggerry, Mary Louise Callas, Farley Rockwell, and Jim Luhr. Two new members
were announced: Farley Rockwell and Alex Nerkoweiz. The secretary's official
GSW inquiry as of 2 p.m. today on the status of the Sorensen-Grossman
"future new member effort" revealed no change in status, but the father-to-be
quipped "Triplets with more coming" would make a more interesting announcement.
This has not been verified by mother-to-be. Dan Milton announced plans for a
spring field trip to the Robertson River Complex of Virginia, a Late
Proterozoic peralkaline complex. The trip will be led by Dick Tollo, who
recently ran a similar trip (for a considerable fee, as a member pointed out)
for the GSA section meeting in Baltimore. The trip was announced for Saturday,
April 27th, but the secretary has noted announcements papering the freshly
painted "Russian white" walls of the U.S.G.S. announcing the same
trip for May 11, so she predicts we will be hearing more about this. President
Barton announced that our April 24th meeting will be a joint meeting with the
Paleontological Society devoted to global change, and that the Washington area
seminar series topic for Tuesday, April 2, would be global change.
Barry Finkelman,
U.S.G.S. presented an informal communication on a geologic explanation for a
weird kidney disease in eastern Europe. A 1983 article entitled "Death
along the Danube" mentioned that about 100,000 people living in villages
built on the alluvial plains along the Danube River, in Yugoslavia, Bulgaria,
and Romania have died from Balkan endemic entropathy (nephropathy). Numerous
theories such as virus, genetic causes, excess lead or cadmium, and selenium
deficiency have been suggested, but none can account for the distribution of
the disease which hits clusters of villages where about 10% of the people in
some villages are affected and other nearby villages have no incidence. There
appears to be a relationship between the endemic villages and Pliocene lignite
deposits; some villages obtain water from shallow wells in alluvium in contact
with lignite, and the water contains many compounds which are related to
degradation of low rank coals and also related to known carcinogens. Barry
addressed the issue of why this diseases is limited to the Balkan countries
when Pliocene lignite deposits are known elsewhere? He suggested that because
the symptoms of the disease do not strike until the victim is 40 to 60 years
old, the low life expectancy of some populations may mask the disease and in
many more developed countries the water supply comes from other sources. Thus
in Yugoslavia, it is the combination of the general good health and longevity
of the population, the water source, and the presence of Pliocene lignite basins
that accounts for the incidence of the disease. Questions by Toulmin and
Stewart. I didn't get the exact rifle,
but in a comment afterwards, President Barton suggested the subtitle "A
macabre prospecting tool for lignite".
Larry Drew, U.S.G.S.,
started off the formal program with a talk on "Quantitative mineral
resource assessment: Why we do it and how". Larry reminded us of the
comment in the paper a few weeks back, that "government scientists are welfare
queens in white lab coats" and that government scientists are being reminded
lately that science is paid for by the taxpayers (and I for one will be
contributing to my salary by midnight on Monday), that they must "be
relevant" and provide the public with predictions and options,
"nice" options. Mineral production creates wealth and society has
forgotten that we use raw mineral materials. Piecemeal decisions are being made
to reduce mineral production, and government has to provide options to policy
makers. Larry Drew a few hisses from the audience with his comment
"There's nothing more passionate than a vegetarian or an
environmentalist". He described a mineral resource assessment of the
26,472 square mile Tongass National Forest of SE Alaska as the creation of one
such option. The purpose of the study was to estimate undiscovered mineral
resources for the U.S. Forest Service to be used for congressionally mandated
land use planning. The study identified 125 permissive tracts that involved 32
different types of mineral deposits. Larry used the example of criteria developed
for a low F, Mo deposit type. Criteria for a tract to be permissive for this
deposit type in the Tongass include the presence of evolved granites, Tertiary
age, depth of erosion of the pluton, and geochemical anomalies. After tracts
are delineated, estimates of numbers of undiscovered deposits of a given type
are made und a computer simulation is used to show the probability of
occurrence of deposits of certain sizes and grades, based on existing grade and
tonnage models for individual deposit types. The talk lasted 19 minutes and 36
seconds. Questions by Brett Milton, Simons, comments by Menzie, more questions
by Zen, Dutro, and Robertson.
Paul Weiblen, University
of Minnesota, spoke on "A new kimberlite(?) occurrence in the old gneiss
terrane of Minnesota". Paul described rocks from outcrops in the Minnesota
River Valley that had been mapped in 1935 as "ultramafic peridotite",
quite unlike the gneisses around them. The outcrops were ignored for 35 years
until a student expressed interest in doing a field project on mantle rocks.
Three types of rocks are noted: massive, serpentinized peridotite, highly
altered, possibly brecciated peridotite with pseudomorphs of olivine or
enstatite (now chlorite), and a kaolinized tuff(?), composed of 90% kaolinite
with pisolitic features that is possibly related to a Cretaceous siltstone that
overlies the 1500 MA Sioux quartzite, which in turn overlies the gneisses. The
area is seismically active, and Paul suggested the possibility of an
intracratonic example of diamond-bearing rocks cutting through younger rocks.
Near Franklin, where 3.5 b.y old gneiss is quarried for road ballast,
Cretaceous siltsone and glacial deposits overlie a circular feature which
appears to be a central diatreme-like peridotite facies surrounded by the
breccia unit, which is surrounded by the tuff. Mineral chemistry was used to
compare the relict minerals in the Minnesota River Valley rocks with mineral
chemistry of known kimberlites. The Minnesota rocks contain forsteritic olivine
with chromian spinel inclusions, but not quite as Fo rich as typical for
kimberlites. Also, diopsidic pyroxene with opx exosolution, Mg-ilmenite,
apatite, futile, and one definitive phase in support of kimberlite, phlogopite.
In terms of major element chemistry the Minnesota rocks fall within fields for
weathered and contaminated kimberlites. The detailed mineral chemistry study
has created a new perspective on the origin of these rocks, and there may he
more such occurrences in Archean terranes covered by glacial deposits.
Questions by Schulz, Robertson, Slack, Stewart, and French. (22.00 minutes).
Robert Park, University
of Maryland and American Physical Society, concluded the formal program with
"Do politicians ever listen to scientists?" Under new federal budget
rules, money belongs to domestic, foreign, or military programs and the
boundaries are inviolate. You can increase a program in one area only if you
decrease that same program in another. The trouble comes in when new programs
are added to a "no growth" fiscal diet. Dr. Park gave us examples of
some price tags of the future, such as the $38 billion dollar space station and
the $17 billion earth observing satellite, which hasn't even been designed yet
so will undoubtedly cost more, which results in possibly $70 billion for big projects
that would all reach peak expenditure at the same time. Dr. Park redeemed
himself for (a) being a physicist and (b) using overheads by showing us his
schematic of the science advisory structure, showing where projects are
initiated within the administration. The President's Advisory Council on Science
and Technology actually meets with the President Every other group, such as the
Office of Science and Technology Policy which sits higher up the food chain
than NSF, DOD, DOE, all sit underneath OMB, which theoretically has access to
the President who is surrounded on all sides by the impenetrable ring of
Sununu. Park took us through the space station as an example of a big program
wending its way through government. The space station has been descoped, not
just redesigned from its original configuration. A staffer wrote in the design,
and the project has been stretched out over a longer period of time to fit into
the budget better. NASA and NSF fall under the same appropriations
subcommittee, along with other agencies which are quite dissimilar in their
functions. And so, the space station has always been in competition with NSF
for funding. The redesigned space station configuration is to be revealed in
April, but by now everybody knows what's in it, and what's not, which is mainly
the science that was its selling point in the Reagan years. But it has a lot of
national image appeal to the administration, so no, in this case, politicians
did not listen to scientists. The 20 minute, 35 second talk was followed by
discussion by Dan Appleman, French, Robertson, and Weiblen.
The particularly lively
meeting, attended by 77, was adjourned at 10:03 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1213th meeting, April 10, 1991
The 1213th meeting of
the Society was promptly called to order by President Barton at 8 p.m. The (in
retrospect) overly lengthy minutes of the 1212th meeting were read and
approved. Visitors Jerry Burgess and Dr. Nikolai Pokonekov were introduced.
Election of new members Bob Seal, Jim Luhr, and Jerry Burgess was announced.
Kevin Burke announced that he has an address for hospitalized GSA President
Doris Curtis, if friends wish to contact her. President Barton announced that
the spring field trip has been rescheduled for Saturday, May 11, rain date May
12. Judy Ehlen pleaded for science fair judges for the upcoming weekend and for
April 27.
Cy Galvin presented an
informal communication on heavy mineral variation along rivers, inspired by a
study of major Virginia river tributaries by Darby, which showed that the
detrital ilmenite composition remained unchanged despite addition of ilmenite
of different composition from side streams. Cy presented an equation to
evaluate the relative contribution of tributaries to discharge of heavies downstream
from the mouth of the tributary and showed that the key factor is to define the
rate at which the heavy mineral weathers relative to quartz.
Doug Crowe, U.S.G.S.,
spoke on Laser microprobe stable isotope analysis: Applications to geology. The
advantages of the laser approach over conventional isotope analysis include the
high spatial resolution possible, high precision and accuracy, rapidity of
analysis and elimination of most contaminants. Doug described applications of
the technique to sulfur isotope geothermometry of chalcopyrite-pyrrhotite pairs
from black smoker deposits, demonstrated that sphalerite and galena in the
Polaris MVT deposit of Canada are not in isotopic equilibrium, and showed core
to rim isotopic zoning in concretionary pyrite in Chattanooga shale. The
technique can also be used to look at oxygen isotopes in silicates, and carbon
and oxygen in different generations of carbonate cements. And yes, a laser will blow up an objective
lens on a microscope. Questions by George Helz, Brooks Hansen, mystery man #1,
Bruce Doe, Robin Brett and Doug Rumble.
John Badding,
Geophysical Lab, examined the issue of "High pressure crystal chemistry of
iron hydride: Implications for the Earth's core". Iron hydride had
previously been proposed as a component of the core, but prior to this study
little was known about its properties because it is unstable at ambient
pressure. John used a diamond anvil cell to make iron hydride by reacting iron
and hydrogen fluid at high pressures and studied the reaction optically and by
x-my as it went. At 27 kbars, nothing happened, but at 60 kbars, iron expanded
suddenly, presumably due to a chemical reaction taking place. Synchotron diffraction
was used to confirm the change. Switching units from kilobars to gigapascals to
keep the audience alert (this, no doubt, after an equation in the informal
communication was what drove several members to drink), John illustrated the
change in x-ray pattern with increasing pressure that showed that the 3 bcc
iron peaks disappear and all iron has gone to FeH by 9.5 GPa; Fell persists to
62 GPa. He repeated the experiment with excess iron, demonstrated that FeH is
stoichiometric, and suggested that the reaction of water with iron to produce
iron hydride and FeO could have occurred druing the formation of the earth, and
that if FeH is stable to high pressures it could have sunk to the core. The
talk ended with 39 seconds to spare. Questions by Mike Palin, Phil Candela, Robin
Brett, Gene Robertson, and mystery man #2 (in a t-shirt, which distinguished
him from #1 in a red shirt).
Hal Gluskoter, U.S.G.S.,
discussed "Coal: Past, present, and future (?)". Hal noted that the
answer to the question of when is coal going to make a comeback is that it
doesn't have to because it never went away. Currently coal produces 57% of all
the electricity in this country. From 1945 to 1969 the price of coal was
relatively constant at $4.5 to $5 a ton; prices jumped in the 1970's and have now
dropped to pre-1970's levels (adjusted for inflation). U.S. energy consumption has leveled off, but
world consumption has increased dramatically. Short term predictions for coal
use are possible, but for the long term there must be a shift from coal to a
new generation of fuels in the next 30 to 300 years. The advantages of coal are
that it is available, technologies for use are well-developed, and although it
is hard to arrive at a precise figure for the resource, the U.S. is among the
top three coal countries along with the USSR and China. Environmental concerns
are a negative factor that may shorten the future of coal as a fuel - a
reasonable estimate of the average ash content of coal is 10%, so 100 million
tons of waste are produced from burning a billion tons of coal. Economics,
public perceptions, and politics all affect coal use and coal scientists, but
Hal expects another a synfuels swing which will increase demands for coal
studies. Questions by Burke, George Helz, speaking on behalf of bacteria, Doe,
Krohn, Zen, Van Oss, Lipin, and the guy in the t-shirt again, who rather reluctantly
admitted that his name was Bob Downs when doggedly tracked down by the
secretary after the meeting.
Attendance was about 80.
The meeting was adjourned at 9:59 p.m.
Respectfully submitted,
[signed Jane Maria
Hammarstrom]
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1214th Meeting, April 24, 1991
President Barton called
the 1214th meeting of the Society to order at 8 p.m. In a departure from our
regular routine, the 1214th meeting was held jointly with the Paleontological
Society of Washington and the entire evening was devoted to global change.
President Barton introduced PSW president John Repetski, who spent a few
minutes on their business, which the GSW secretary chose to ignore as she spent
the time fruitfully counting the crowd which numbered a high 106. Nine visitors
were introduced - David Wicksam, Julie Lewis, Grace Haggerty, an Alex, Damian
Hotkinson, Carmen Garcia, Glen Sandford, Jessica Stevenson, and Nancy Budd.
Eight new members were announced - Julie Lewis (already counted as a visitor),
Smithsonian, Kevin Kivimaki, Smithsonian, Barbara Bittner, Paul VI High School,
Jack Parrotto NRC, Jane McDudd, St. Agnes School, Stacie Kreitman, Fair- fax City
schools, Elizabeth J. Palmer, Pittsville Middle School, and Mary S. Myers,
Henrico County schools. Dick Tollo reminded us about the May 11 field trip.
There was a brief announcement about the upcoming Centennial meeting and the
book that is being prepared in honor of the occasion. A show of hands indicated
that about 35 members would buy the book (this must be wrong since there were
100 people at the meeting - although in light of our somewhat disastrous
T-shirt extravaganza a few years back, sounds about right). The final announcement
of the evening was the long-awaited arrival of Joel Grossman.
Scott Wing, Smithsonian,
took us beck to the Eocene at the start of the formal program, with his talk on
"Global warming and terrestrial vegetation in the early Eocene". We
learned that the early Eocene was a time for which we have overwhelming evidence
that earth was warmer than today. Scott suggested that the rock and fossil record
can be used to examine past climates and to look for responses to climate change
to see how ecosystems respond to force factors. Eocene floras from the
continental interior include species such as palms and tree ferns which are
extremely intolerant of cold weather. These and other paleobotanic data
indicate minimum Eocene temperatures of 0, not -3 degrees as predicted by computer
climate simulation and are broadly consistent with foraminifera temperatures.
Questions by E-an Zen (2), Tom Cronin, Bill Houser, Frank Whitmore, Peter Warwick,
Dennis Krohn, Lee Broadhurst, and Kevin Burke.
Harry Dowsett, U.S.G.S.,
presented the second talk with coauthors Tom Cronin, Richard Poore, and Robert
Thompson on "Paleoclimatic reconstruction of the Pliocene North Atlantic region".
Harry described the PRISM projects (Pliocene Research, Interpretation, and
Synoptic Mapping) which deal with oceans, ocean margins, and continents. CO2
increased from 315 ppm in 1959 to 352 ppm in 1989 which suggests a global
warming of about 3 degrees. Doubling of CO2 would affect sea level
and ocean circulation so improved predictive methods are needed. The Pliocene
is a good time for warm earth reconstructions because the mid-Pliocene was
warmer than today, global geography was similar, near modem floras and faunas
existed, marine and continental records are available and chronology is
well-established. Ocean margin reconstructions based on ostracods, which are
highly sensitive to temperature and salinity show an Early Pliocene warming
followed by cooling. This is consistent with data for oceans from planktonic
forams. Fresh water diatoms, plant fossils, and pollen temperatures are used to
establish the climate data record for continents. Data show that the west coast
was drier and inland areas wetter than today. The talk ran 3 seconds short. Questions
by Wing, Burke, Whitmore, Huber, Kathy Krohn, and Rubin.
Alan Robock, University
of Maryland, ended the evening on a futuristic note with his talk on
"Climate change in the next century: sun bathing at Point Barrow in
2050?" Alan discussed global change in terms of the climate system and the
greenhouse effect and emphasized that many things can cause climate to change,
so models need to consider land surface interactions with climate, such as soft
moisture, the albedo, etc. All the greenhouse gases - CH4, CO2,
N2O - change over time and increase due to human activity - and even
if they step increasing they will be around for awhile. The US produces 21% of
the greenhouse gases - Europe 14%, India 4% - and the question that arises is:
how can the rest of the world develop without an increase in greenhouse gases?
Although global warming can be demonstrated, three of the highest resolution
global change models are contradictory for regional warming. Questions by
George Helz, Dick Fiske, Ann Dorr, Susan Sherwood, Mark McBride, Ken Towe, and
a guy in a yellow sweater. The meeting was adjourned at 10:20 p.m.
Respectfully submitted,
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1215th Meeting, September 25, 1991
The 1215th meeting of
the Geological Society of Washington was delayed by the arrival of the
Apocalypse, or more precisely, by a quasi-religious movie about environmental
disasters as possible forerunners of the same. When loyal members of GSW showed
up at 7:30 for the usual beer and good fellowship, the Powell Auditorium was
full of other, much dressier people. We waited outside, but come 7:45 it was
still full, and likewise at 8:00 p.m. To make matters worse, it was raining in
nontrivial amounts, so that our beer was being seriously diluted: an environmental
disaster unprecedented in the annals of the Society. After some discussion, a
representative of the Cosmos Club allowed the soggy and disgruntled geologists
into the Club's outermost reception room and supplied free beer, on condition
that we not stray into other, more sacred precincts. Eventually, at 8:20 or
thereabouts, the cinematic Apocalypse came to an end, and GSW members were informed
that they could go to the Auditorium. The Cosmos Club management evidently
intended us to go out and get wet again, as some consternation was evident when
a large fraction of us, including your stand-in secretary, walked through the
dining room instead.
As we streamed in, we
encountered the dressy folks, still milling around, chatting and greeting each
other, and evidently in no great concern to move on until they noticed the
arrival of a large group of wet, beer-swilling geologists. After that they
cleared out of OUR auditorium with commendable speed. A mere 10 more minutes
and the auditorium was set up for us, and President Barton was able to call the
meeting to order at 8:32 pm.
An abbreviated version
of the minutes of the 1214th meeting was read, and more or less approved.
President Barton, reading from an overly detailed agenda, thanked Jane for
reading them. The membership stood for a moment of silence in memory of Paul
Averitt and Juergen Reinhardt, former members who had died recently. Two guests
were introduced: Leonid Popov, of the All-Union institute for Geological
Research, St. Petersburg, introduced by Bob Newmann, and Catharine McMullen,
introduced by Kevin Burke. The acting secretary then read the names of seven
new GSW members: Dorothy Burch, Nancy Gardner, Eileen Molino, Barbara Mertens,
Eileen Steinkraus, James Schmidt and Hengameh Mirzai.
Next Dan Milton announced
the GSW fall field trip, a visit to the dinosaur footprint locality at the
Culpepper quarry, would be held on November 16, and Leanne Milton announced
that there would be a parent-child workshop on overcoming fear of Science Fair
projects, or somesuch, on October 13. The president then moved on to the big
item on a very crowded agenda: the need for a dues increase to pay for the high
cost of meeting at the Cosmos Club. Though it was a somewhat inauspicious
evening to bring the subject up, Treasurer Fred Simon gave a brief but compelling
presentation of our rising tide of red ink, and Steve Huebner, as Chair of the
Finance Committee, presented the membership with options for changing the dues
structure. President Barton then presented the audience with several proposed
amendments to the GSW bylaws. These included (1) changing the GSW fiscal year
to end June 30, to make the fiscal year close-out easier (2) having a second
dues notice go out to non-payers four months after the first notice, (3)
eliminating the 2-year grace period, so that nonpayers would be dropped form
GSW membership and the mailing lists as soon as it was clear that they had ignored
the second dues notice, (4) raising the dues for all categories of members, but
establishing a new student-member category, at a relatively low dues rate, (5)
eliminating the retired-member category as a separate class of membership, with
retired geologists to be either regular members or corresponding members (their
choice). The President told the audience to mull things over, and we proceeded,
at last, to the formal program.
The first speaker, David
Grandstaff of Temple University, spoke on the topic "Nuclear waste
disposal: A comparison between granite, tuff and basalt", or would have,
if he'd had more time. Most of his twenty minutes was consumed introducing the
idea that nuclear wastes were difficult to dispose of, as they tend to heat up,
attack their containers, and whatnot. He then described some experimental work
of his own, in which various geologic materials (tuff and basalt were reacted
with aqueous solutions, at hydrothermal conditions, and the products examined.
The compositions of the clays formed and the final chemistry of the solution
was found to depend on the composition of the starting rock powder and the
composition of the starting solution. It seems that more work is indicated
although probably you could store radioactive waste in either tuff or basalt,
if you had to. There were questions from George Helz, anonymous, and Gene
Robertson.
Next, Frank Ireton of
AGU spoke on "Volcano Speleology of the Snake River Plain". This
well-illustrated talk gave us a tour of the extensive lava tubes that formed
within basalt flows of the Snake River Plain. The tubes contain a variety of
interesting features, including lava drips and piles that closely resemble the
stalactites and stalagmites of limestone caves. These features even attract the
same kind of greedy vandals who deface other unprotected caves, leading to the
need for barriers at entrances and monitoring of access. Nonvolcanic remains
found in the caves included the mummified carcass of a grizzly bear. Ireton suggested
that the bear slid into the cave on a snow ramp and bedded down for the winter,
only to find the snow ramp gone and himself stranded, come spring time. Alas,
it seems that there are occasions when a bear would be well-advised NOT to
sleep through the winter... Questions by Bruce Lipin, Tom Simkin, Bill Lee, and
Kevin Burke.
The last speaker, Walter
Stewart of NIH, addressed the Society on what has become known as "The
Baltimore Case", after Dr. Baltimore of MIT, who has become embroiled in a
case of apparent scientific fraud carried out by a subordinate in his
laboratory. Speaking without slides or notes, Stewart summarized the history of
his involvement with the investigation, which began when a post-doc in the MIT
biochemical lab, Dr. Margot O'Toole, found she could not duplicate some results
reported in an earlier paper by Dr. Imanishi-Kari, Dr. Baltimore, and others.
When she looked at the original laboratory notes that supposedly were the basis
for the paper, she found (she says) that the original results did not support
the paper either: in fact, they were the opposite of what should have been observed.
She headed straight for Dr. Baltimore, whose name was on the paper largely
because the work had been done in his lab, to report that there was a serious
problem with the paper, and that the results could not be reproduced.
Apparently the suggestion did not go down well, she was fired, and many years
of bitter controversy have followed. The NIH investigators were involved partly
because the work had been funded by NIH, and partly because they were among the
few willing to believe in the possibility that it was a fraud case. After much
grief, Dr. Baltimore has conceded that there was a problem of some sort, but
the only person to be seriously hurt by the process was the whistleblower, Dr.
O'Toole. Despite the lateness of the hour, the presentation generated consider-
able discussion, with questions by anonymous, Bruce Doe, John Slack, Dan
Milton, anonymous, anonymous, Bruce Lipin, Mac Ross, Catherine McMullen, Tom Simkin,
Kevin Burke and Steve Huebner.
President Barton then
announced the program for October 9, and adjourned the meeting at 10:25
p.m. Attendance was approximately 75-80
for the first talk, and 65 later, but the audience was more than usually
restless, so the number is a little uncertain.
Respectfully (not
respectively!) submitted
Rosalind Helz,
Substituting for Jane Hammarstrom
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1216th Meeting, October 9, 1991
President Barton called
the 1216th meeting of the Geological Society of Washington to order at 8:00
p.m. The minutes of the 1215th meeting were read and approved, without mishap.
Barton then called for a moment of silence in memory of John Philip Schafer and
of Ralph Miller, both former members of the U.S.G.S. and of G.S.W. Several guests were introduced, including:
Lynn Claflin of the Joint Oceanographic Institute, Janet Norton of the Pacific
Marine Branch, U.S.G.S., Dave Smith of the Branch of Chemistry, U.S.G.S., Lars
Holmer of Uppsala University, Lorraine Wolfe, Tim Appenzeller and Brad Blase.
Barton then read an
announcement about the upcoming Dinosaur Stomp field trip, to be held on
November 16, and read the slate of nominees for officers of G.S .W., as
required by the bylaws. Next Steve Huebner gave a repeat presentation of the
need for a substantial dues increase. This generated much discussion by the
membership, with comments from Tom Dutro, Peggy Appleman, E-an Zen, Dick Fiske,
Dallas Peck, and Bruce Doe, among others. Among the suggestions that flew back
and forth was that new U.S.G.S. geologists would be inspired to attend G.S.W.
more regularly if Peck and other, lesser Big Enchiladas graced the meetings
with their presence more often. President Barton cut off discussion of this perennial
favorite topic at 8:40 and moved on to the formal program.
The first talk of the
evening, by Nathalie Valerie-Silver and Paul Silver, was on the topic
"What is the relationship between the behavior of geysers and the occurrence
of large earthquakes?" Using a long-term eruption record (1973 to present)
compiled by a local woman, the Silvers had determined that there is an increase
in the time interval between eruptions of the Calistoga "Old
Faithful" geyser just before and after major earthquakes in the region.
The effect of major rainstorms is the opposite: the geyser erupts more
frequently when there's more water in the ground. So far the data set includes
three major quakes: the Oroville, Morgan Hill, and Loma Prieta quakes. The Silvers argued that even though the number
of large quakes in the time interval studied was small, that the correlations
were significant. If so, then monitoring the eruption interval of this geyser
would provide 1-2 days warning that a major quake was imminent somewhere in
northern California. The talk generated an extended discussion from Moto Sato,
with questions from Bruce Lipin, Bruce Doe, Dan Milton, and Gene Robertson.
Robert Ridky, of the
University of Maryland, spoke next, on the subject "Did subglacial melting
cause massive flooding in the Finger Lakes region: Evidence from glacial land
forms." The heavily-glaciated Finger Lakes region contains, in addition to
the famous lakes, several enormous drumlin fields. The speaker has made a study
of the orientation of over 1500 drumlins in the area, and has concluded that
their formation and orientations were produced during steady-state ice flow,
rather than being the result of catastrophic flooding. There were questions by
Jeff Macnamara and E-an Zen.
The final presentation
of the evening was by Gabriele Paone, of the Department of the Interior, who
addressed the Society on the subject "Proposed new ethics rules for
Federal employees and their effect on professional societies such as
G.S.W." Paone came with copies of a
handout that summarized both the existing rules and statutes, and crucial
sections of the proposed new regulations. The speaker led us through the bad
news, prefacing his discussion by saying that normal reasonableness and logic
were not useful guides to what is permitted and what is not. The effect of the
new regulations will indeed make it extremely difficult for G.S.W. to soldier
on. There was extensive discussion, with contributions and questions from Greg
Sohn, Steve Huebner, E-an Zen, Margot Kingston, Nathalie Valette-Silver, anonymous
in blue sweater, Anne Don:, Greg Sohn, Kathy Krohn, Peggy Appleman, Bruce
Lipin, Moro Sato, Mike Brown and others.
President Barton
announced the program for the next meeting, and adjourned the society at 10:30
p.m. Attendance was 82.
Respectfully submitted,
Rosalind Helz, acting
for Jane Hammarstrom
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1217th Meeting, November 6, 1991
President Barton called
the 1217th meeting of the Society to order at 8:12 p.m. on Wednesday, November
6, 1991. The 12 minute delay was mused by microphone problems which were dealt
with by no less than 6 of our officers and front row members. Minutes of the
previous meeting were read and approved. New members Tom Blackburn, Lorraine
Wolf, and Kathleen McMullen were introduced. Visitors included Ed Young, Wayne
Purcey, Tony Stassi, Ton Blackburn, and a Juan (I'm sorry I missed your last
name) of University of Grenada visiting U.S.G.S.. Dan Milton announced the
November 16 field trip to see dinosaur footprints. E-an Zen made an
announcement about the results of an October 22 hearing on the proposed rules
by the Office of Government Ethics where witnesses representing government and
professional societies spoke. The next item of business was a vote to change
the by-laws to raise dues and change the fiscal year to end on June 30. The
actual voting was preceded by an in-depth discussion of important concerns.
Jingle Rupert objected to the omission of the s in the word "he" in
the by-laws - that's "s" before "h", as in she-he-it - to
which President Barton, in keeping with the mood of the times responded by appointing
Jingle as chairman of a committee to unsex society matters - and, so rattled,
almost forgot to get an actual vote on the issue. One of the Bruces moved for
approval of the fiscal year date change, which was seconded by several members
all speaking at once, and unanimously approved by the 100 members in attendance
that evening. On the matter of the dues change, Bill Melson wondered if a dues
increase would restore pretzels and Ray Rye wondered flit would get us a coat
rack. George Helz mercifully moved in favor of the dues increase, resoundingly
seconded, and all approved.
Brenda Bohlke, of
Parsons Brinkerhoff, spoke on "Engineering geology of the world's largest
tunnel for sewage effluent, Boston Harbor". In her enlightening talk, we
learned that there is a role for geology in sewage. Massachusetts has to clean
up the harbor by 1999, and so an aggressive program is underway to construct conveyance
tunnels and treatment facilities to turn primary sewage to sludge and
fertilizer pellets and discharge it offshore on the sea floor via a 24' TBM tunnel
with vertical risers and diffusers at the end. To design the project, an extensive
boring program was accompanied by detailed geophysics, including standard
seismic reflection to define surface sediments, marine clays over till, and
differentiate where bedrock, the Cambridge argillite started. Critical factors
in the diffuser design include the anchor drag of ships and, a what proved to
be a popular item during discussion, concern about greaseballs. The talk ran a
precise 20 minutes. Questions by George Helz, Kevin Burke, the guy sitting next
to Kevin Burke in a blue shirt, Dan Milton, Steve Huebner, E-an Zen, and Gene
Robertson.
Jim Luhr, Smithsonian,
spoke on "Experimenal plagioclase-glass equilibria and estimation of
magmatic water contents". Jim presented a new model using plagioclase and
coexisting melt to estimate water contents of magmas just before eruption, an
important thing to know because water can influence the physical properties of
magmas, such as viscosity. The model uses equilibrium exchange reactions of
albite in plagioclase and melt, experimental data on El Chichon magmas, and a
regular solution model for the silicate. To use the method, one needs chemistry
on plagioclase and melt, and an independent estimate of temperature. Jim
applied the model to Mount St. Helen's, El Chichon, and Pinatubo and noted
complexities that arise from calcic rims on plagioclase. Jim spoke for 19
minutes. Questions by Toulmin, Hammarstrom, Sato, and Nershacher.
Stewart Eldridge, ANU,
concluded the formal program with "A SHRIMP's eyeview of diamonds and the
mantle". The ANU SHRIMP makes spots that are 30 microns across by 3
microns deep that produce data on U/Pb in zircon, REE data and S isotopes,
among other things. Stewart described a SHRIMP study of zircons from African
kimberlite pipes to corroborate a 250 Ma Rb/Sr age. He found a population with
this age, but also found evidence of earlier, 2-3 By ages. Zircons are not a
standard phase in the mantle, so these older ages could reflect an earlier
kimberlite event. The zircons are less fractionated in HREE than granite
zircons, so they are not crustal zircons fallen into kimberlites. For sulfide
inclusions in diamonds, you usually get meteoritic sulfur isotope values, but
some of the kimberlite pipes have much higher d34S
values. Pb/Pb data on the diamonds gives ages from 2 b.y. to the future. All
this led Stewart to suggest, in overtime, that diamonds grow in the mantle over
a considerable period of time and subduction processes, carrying in sedimentary
sulfides and such, may play a role in the location of diamond occurrences.
Questions by Barton, Lipin, Tollo, Zen, Sorensen, Boyd, and Melson. The meeting
was adjourned at 10 p.m.
Respectfully submitted,
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1218th Meeting, November 20, 1991
President Barton culled
the hard-to-count crowd of somewhere between 61 and 71 of us to order at 8:01
pan. Guests Leonid Brooke and Brendan Shane were introduced. The November 16th
field trip to Culpepper Quarry was pronounced a success - 80 to 90 attended. Is
there any relation between a standard deviation ±5 GSW members at a gathering
and the number of people that comfortably fit around a keg of beer? A moment of
silence was observed in memory of member John Hosterman. E-an Zen presented an
informal communication on potholes at Great Falls. Having exhausted most of the
disciplines of geology, E-an has apparently overcome his fear of water and has
taken to wandering around staring at rivers until he sees something new that he
can give a talk about. In fact, he sees 2 kinds of potholes exposed in old
river channels - floor-types have circular bottoms with vertical walls and
lateral types are segments of circles with overhangs. The 2 types formed in
different parts of the old channel and by different processes and study of
their distribution and size may hold clues to paleoflow regimes. Questions by Toulmin, Huebner, Rubin, Galvin,
Hearn, and Jerry Barton.
In a slight deviation
from normal procedures, the informal communication was followed by the
introduction of 7 new members: James D. Bennett, Raquel Frenk, Celia Barteau,
Lynn Johnson, Suzanne Weedman, Chris- line Schneider, and Brendan Shane.
J.K. Bohlke, U.S.G.S.,
kicked off the formal program with "Halogens and noble gases in fluid
inclusions: indicators of fluid sources and reactions in the Earth's
crust". J.K. described a new microanalytical method using irradiation and
mass spec analysis of noble gas isotopes to determine compositions of aqueous
fluids in inclusions. Br/Cl and I/Cl
ratios in mineral districts can vary by three orders of magnitude relative to
seawater and can vary within a given vein system providing clues to processes
of vein evolution. He applied the methods to field studies of the Mother Lode
gold veins in California, where he showed that the observed spectrum of fluid
inclusions which range from high T, high CO2 to low T, CH4-bearing
represent mixing of two fluids rather than evolution of a single fluid and to
the Hansonburg, New Mexico MVT Pb-F deposits, where the low Br/Cl ratios in the
homogeneous fluid inclusion population in fluorite and excess radiogenic argon
may result from evaporite dissolution. The talk ran a 1 minutes and 30 second
tad over the allotted time. Comment by Barton, and questions by George Helz and
unidentified.
Arlin Krueger, NASA,
spoke on "The dispersion of the Mt. Pinatubo plume". A fringe benefit
of Total Ozone Mapping Spectrometry (or TOMS), the technology used to monitor ozone,
is that you can also monitor SO2 because the wavelength range in the
near-ultraviolet for ozone shows SO2 well enough to discriminate.
This gives us a neat way to directly determine volcanic output compared with
previous methods which rely on ice core data and petrology. Arlin showed a
series of images that tracked the progress of the Pinatubo plume from June 15
to June 23 as it drifted westward across the S China Sea and spread out across
Africa. Whereas the El Chichon cloud stayed in the northern hemisphere for
about 9 months, the bulk of the Pinatubo cloud is still in the southern
hemisphere and may have a larger effect on climate. The estimate of an initial
18 million tons of SO2 from Pinatubo dwarfs the 7 million tons from
El Chichon. Questions by Helz (George), Simkin, Doe, McClellan, and Lipin.
Elaine McGee, U.S.G.S.,
ended the program with "The combined effects of acid precipitation and
urban pollution on the Washington monuments". Elaine described 2 types of
deterioration that contribute to the crumbling of our capitol city as a result
of our pH that falls in the range 4.2 to 4.4, where anything below 5.6 is
considered acid rain - dissolution and alteration. All that black stuff on
buildings that isn't organic is gypsum which forms crusts in areas sheltered
from regular washing and eventually spalls off. Elaine described a study of 5
monitor sites that include urban, rural and suburban areas to monitor weather
and pollution effects and evaluate the contributions of various species such as
H+, SO4, and NO3 to dissolution. Dissolution effects
limestone more than marble, and urban SO4 accumulation is 16 times
greater than in suburban and rural areas. With a minute and 45 seconds to
spare, Elaine answered questions from Appleman (Dan), Doe, Galvin, Zen,
Huebner, Stewart, Simkin, and Sato.
The meeting was
adjourned at 9:45 p.m.
Respectfully submitted,
MINUTES OF THE GEOLOGICAL SOCIETY OF WASHINGTON
1219th Meeting, December 4, 1991
President Barton ended
his reign by calling the 1219th meeting of the Society to order at 8:06 p.m. -
a tad late, but otherwise without incidence. Minutes of the previous meeting
were read and approved. The members observed a moment of silence in honor of
past president and long-time member Norm Hatch. Two new members, Jack Reale and
Ron McGregor were introduced, as were two guests, Vladimir Burger and Ian
Carmichael. President Barton announced the program for the January 8 meeting.
There were no informal communications.
Paul Barton, U.S.G.S.,
gave his Presidential address on "Mineral textures: New frontiers in old
territory". Paul described how
mineral textures constitute an integral part of geologic mapping by providing
microscopic field data that can help interpret macroscopic field data and vice
versa. The "old" techniques of ore microscopy and petrography
concentrated on identification of minerals or sequences of mineral deposition
using classic criteria of superposition. New techniques include the use of
microprobes, fluid inclusion studies, and phase diagrams for sampling and interpreting
observed mineral textures. Paul illustrated his talk with spectacular
photomicrographs of ore and gangue textures in epithermal and volcanogenic
massive sulfide deposits and showed textures indicative of relative degrees of
supersaturation and selective etching during crystal growth. The degree of
silica saturation affects sulfide deposition, so silica textures are important
in studies of sulfide deposits.
After 45 minutes or so
(the secretary wasn't timing), Paul departed the stage to enjoy his just
dessert and the 90 meeting attendees retired to the back of the room to refuel
for the annual meeting.
Respectfully submitted,
Minutes of the 99th Annual Meeting of the
Geological Society of Washington
December 4, 1991
The 99th Annual meeting
of the Society was convened at 9:21 p.m. Tom Dutro, dubbing for absent Council
Secretary Brace Wardlaw who was off in Pakistan drawing fire instead of being
here drawing fire, read the minutes of the previous annual meeting which were duly
approved. I read the report of the meetings secretary, also approved, and Dutro
resumed the Wardlaw role to give the Council secretary's report, which was
approved after some perceptive soul noted that Van Driel and Tollo were not
mentioned as the auditing committee.
Treasurer Fred Simon
reported a healthy Bradley Fund balance of $17,022 and a sickly (but not quite
dead yet) General Fund which owed $1700 to the Bradley and Endowment Funds.
President Barton read Tollo and Van Driel' s auditing committee report
which showed the books to be correct and verifiable; the report was approved.
Kathy Krohn gave us an
in-depth membership committee report, complete with zip- coded pie charts which
showed that 62 % of dues paying members live in the Washington metropolitan
area. The significance of this escaped entry in the secretary' s notes. We
gained 56 new members in 1991; 670 out of 1000 on the rolls paid dues, we had a
15% drop out rate; the field trip and AAPG Explorer ads brought in a few; and
all of the deceased members had paid dues.
Judy Ehlen gave the
Public Service Committee report, noting that 16 members judged 10 area science
fairs, she also thanked Dan Milton for organizing successful field trips, and
made her by now routine pleas for more member participation in science fairs -
as judges that is. Then she gave out her phone number and said something about
"For a good tune call Judy".
Gene Robertson restored
propriety with has report on the Centennial Committee's progress. Gene
announced the Feb. 24, 1993 banquet meeting - to capture the true 1890's scientific
spirit wear your tuxedo, the March 10 commemorative scientific meeting, and mentioned
highlights of the imminent Centennial commemorative book about the Society.
President Barton thanked
Bruce Lipin for doing such a good job as program chair, and Liz Koozmin for the
her superb work on our new newsletter, Outcrops.
George Helz, as chair of
the Best Paper committee, gave us an entertaining account of the science
covered in 1991 meetings. The Great Dane award for best informal communication
went to Barry Finkelman for briefing us on Balkan endemic nephropathy. The
committee noted 4 talks for honorable mention, Doug Crowe on laser microprobe
stable isotope applications, Elaine McGee on acid ram effects on Washington
monuments, E-an Zen on producing the Pioneer batholith, and Roz Helz on moving
mushes. The money, however, went to Stu Eldridge for the second best paper
award for his talk on SHRIMPing diamonds and the big winner was Dan Appleman
for his remarkable account of the remarkable scientific career of James Dwight
Dana.
Dan then emerged as the
Sleeping Bear chair, and awarded the coveted cup to Brenda Bohlke, who during
the course of her talk, gave us a quantitative assessment of the large amounts
of sewage being dumped into Boston Harbor with her remark, and I quote Brenda
here, "That's a lot of shit!"
Bevan French, nominating
committee chair announced the slate for the election and the proposed new
officers for the Society were elected by acclamation and the meeting was
adjourned without further ado.