GSW: 1986
MEETING MINUTES
Geological Society of
January 8, 1986
President Brett set a punctuality precedent
by calling the 1146th meeting to order at 8:05 pm. Despite freezing weather a
passel of visitors was introduced, including Janet Herman, an Environmental
Scientist, Carolyn Olsen, Isabella Corelli, Bruce Johnson, Erhart Lab, Rich
Hildebrand and colleague Ed all of the USGS, Luret Savoy, University of
Colorado, Elizabeth Ryan of Langston Hughes High School, introduced by her
father, Mike and Laura Widiker of West Virginia. My apologies to those I may
have missed due to unhoned speed writing skills. New members,
President Brett announced that since
"making money makes the world go round", the bargain priced GSW
tee-shirts were still available. He then read a thank-you note from the 1985
recipient of the Best Paper Award, Harry McSween. Third Brett hinted darkly at
some discordant exchange between E-an Zen and the Sleeping Bear Award
Chairperson, and promised to further enlighten us only when Zen was present to
defend himself.
William Seyfried gave the first talk
entitled "Ridge-crest hydrothermal processes: experimental models and
field observations." With a wry
glance at our president, Seyfried noted the difficulties of studying these
black smokers in situ even with the
The second speaker, Linda Gunderson,
presented a "geochemical and tectonic model for the formation of the
Fe-U-REE deposits in the Proterozoic rocks of the Reading Prong". We
viewed a slide series of lithologies and chemical compositions, discovering
that Gunderson's favorite rocks and adjective are the same and quite nice. The
magnetite deposits of her study area started out as banded iron formations back
in a Precambrian basin. Relaxed listeners were startled by a slide which showed
the uranium content of Reading Prong rocks to be 40,000 ppm, but our speaker
quickly calmed us with the word "typo." As indoor radon is such a hot
item, this was a disquieting error indeed! Questions by Robertson,
It was a banner evening for geochemists, as
the final talk by Paul Hearn was entitled, "Geochemistry of rock-water
interaction in the
President Brett adjourned at 10:02 pm,
which awakened a former president of GSW, caught sleeping against the wall. One
hundred and seventeen other people attended.
[signed Margo Kingston]
Geological Society of
January 22, 1986
President Brett called the 1147th meeting
of the Geological Society of Washington to order at 8:05 pm. The minutes of the
previous meeting were read and corrected. New member, Jill Harvey was presented
and four visitors were introduced. Suspicious of the sparse attendance after
only one meeting with new officers, President Brett invited members to share
taped versions of the Planet Earth series so that TV devotees would attend GSW
for a live and really earthy performance. A suggestion from the floor that GSW
might be taped was ignored, but our President's impassioned pleas for early
dues payments, generous donations and desperately needed informal
communications prompted Dave Stewart to suggest that Brett already sounded like
public TV. Undaunted, Robin continued
with praise for the outgoing program chairperson, Dan Milton and announced his
successor, Elaine Padovani. A rash of narcolepsy among attendees possibly
related to beer consumption spurred a member to question whether attendance
numbers should include consciousness as well as physical presence. Jane
Hammarstrom then alerted us to a mild epidemic of kleptomania as order forms
for GSW tee shirts are disappearing at meetings; without orders being returned.
Our first speaker, A.J.W. Gerrard who is a
geomorphologist not a geologist, gave a paper entitled, "Rock control in
the granite landforms of southwest
Our second speaker, Richard Benson spoke of
the "search for the ancient Straits of Gibraltar". As he is not a
structural geologist, he described the paleontological evidence for the abrupt
transformation from a shallow sea to a deep ocean basin, thus precipitating a
catastrophic flow of Atlantic waters into the
John Ferry, a petrologist, not a hydrologist
presented a paper entitled, metamorphic hydrology at 13km depth and 400 to
500°C. Clues to fluid flow in calc-silicate rocks can be found in the
distribution of minerals such as wollastonite and map patterns of fluid/rock
ratio indicate the degree of channelized fluid flow. Increased metamorphic
grade means less channelization and more pervasive flow. Wasn't
The meeting adjourned at 10:10 pm, with 73
attendees, including one sleeping bear and an average of three sleeping humans.
[signed Margo Kingston]
Geological Society of
February 12, 1986
President Brett called to order the 1148th
meeting of the Geological Society of Washington at 8:08 p.m.. New member, Janet
Crampton of the AGI was announced and three visitors were introduced, including
our third speaker, Craig Nicholson. Attendees stood in silence after Brett
informed us of the deaths of Bill Menard, past Director of the USGS, and Allen
H. Nichal, a member of GSW. The meeting continued with several announcements.
The score is now 110 to 9; one hundred and ten missing GSW tee shirt order
forms to nine orders. Also, volunteers are needed to judge at local Science
Fairs. Why not wear the tee shirts while judging? Not only is April, Boy Scout
Geology Badge month but April 20 is Geology Day in
First speaker, John Sutter, who may be the
fastest gun at the USGS, gave a talk entitled, "laser probe argon-40 to
argon-39 dating of single mineral grains in situ". In order to
degas material for argon determination, Sutter lines up pre-irradiated 2mm
thick disks and fires away, putting as many as 50 shots into a single biotite
grain in a minute and one half! Melt pits must be the proper diameter and
depth, and speed is essential to maintain the near perfect vacuum. Sharpshooter
Sutter makes apparent age determinations on minerals as young as 28.2 my. Applications
include studies of slaty cleavage generation, zoned amphiboles and timing and
nature of diagenesis of authigenic feldspars. Our speaker mentioned a new
mineral, "age-wise-hornblende"; or in petrologic German, das
Alterweisehornblende. Questions by Freeborne, Sorensen, Zen, French, Robertson,
Doe and Brett.
Second speaker, Tom Wright regaled us with
slides of a perfect summer vacation spot, while illustrating his talk entitled,
"folding and cleavage development in the Meguma terrain,
Third speaker, Craig Nicolson, gave a talk
entitled, "deformation along the southern San Andreas: twisty blocks and
left-lateral faulting". He began by stating that his slides were not for
kids, and he was right, especially
President Brett reminded us of our
homework; more tee shirt orders, more informal communications and mostly dues,
then adjourned the meeting at 10:08 p.m.
Attendance was 110.
[signed Margo Kingston]
Geological Society of
February 26, 1986
President Brett called the 1149th meeting
of the Geological Society of Washington to order at 8:07 pm. After the minutes
were read and approved, three visitors, Willy Accame, Michael Max and Allen
Wilson were introduced. As usual, Brett exhorted us to pay our dues, and to buy
tee-shirts. After Ray Rye called for volunteers to serve as Science Fair
judges, Brett suggested that this provided an opportunity to advance one's
child at school. Upon hearing that there were again no informal communications
, Brett threatened to lash attendees to their seats in the Powell auditorium
until someone volunteered. That might have led to some lively and very informal
communication indeed, but scientific quality would have been suspect.
Steven Shirey, our first speaker, gave a
talk entitled, "Small scale, three component isotope heterogeneity in the
mantle sources for mid-ocean ridge tholeiites". In his field area, about
14km of the North Atlantic ridge near the
Lucy McCartan, our second speaker, lugged a
huge clock onto the stage but gave it nary a glance during her well timed talk
entitled, "Factors controlling biogenic silica fixation in the sedimentary
record: an example from the Miocene-Pliocene Chesapeake group." The
Miocene was an exciting time, as both igneous activity and diatoms flourished.
Then as now, conditions necessary for the production of diatomaceous sediments
included the availability of nutrients, proper temperature and pH, a paucity of
carbonaceous and terrigenous suspended sediments, and diatoms more wily than
the grazers who seek to devour them. Usually upwelling ocean currents transport
necessary diatom nutrients but along the east coast, detached cold water eddies
off the
Third speaker, Mark Gettings continued the
McCartan mighty Miocene show with a talk entitled, "Relationship of young
mafic plutons to seismicity in the eastern
After giving us the same old homework, tee
shirts, informal communications, science fairs and dues, President Brett
adjourned the meeting at 9:50 and 41 intrepid attendees rushed out into the
snowy night.
Respectfully submitted,
[signed Margo Kingston]
The Geological Society of
March 12, 1986
First Vice-President Fiske called the
1150th meeting of the Society to order at 8:03 p.m. The minutes of the previous
meeting were read and approved. The acting Secretary then read the names of two
new members, and the one actually present, Marge Summers, stood and was
applauded. Next E-an Zen announced that we still needed science fair judges and
that sign-up sheets would be posted at the back of the room.
Then, to celebrate the absence of President
Robin Brett, we had an informal communication from Bruce Doe, on the subject of
what acid rain is doing to downtown D.C. It's dissolving DAR Memorial Hall, The
Red Cross building and the
The first speaker of the evening was David
James, of DTM, speaking on "Earthquake Reflection Seismology: Results from
The next talk, by Rodey Batiza, was
announced as being "A General Hypothesis for the Origin of Seamounts at
and near Mid-Ocean Ridges," but the speaker informed us he wasn't going to
talk about that. What he did want to talk about was the fine structure of the
ridges, in particular their tendency to be segmented, every 30 km or so, by
offsets of various sorts. He divided these offsets into several categories, the
most memorable of which are the Small Non-Overlapping Offsets or
"SNOO's," which is what he suggested the audience might be doing
shortly. This 30-km segmentation was thought to reflect similar segmentation in
the magmatic plumbing, with big MORB chambers centered in the segments, and
lesser amounts of not-quite-MORB magma trickling through at the offsets, to form
the small seamounts alluded to in the nontitle of the talk. Questions by Ralph
Haugerud, E-an Zen (two), George Helz, Sorena Sorensen, and Bruce Doe, with a
comment from Dick Fiske.
The last talk of the evening was by I-Ming
Chou, U.S.G.S., on the subject of the permeability of precious metals to
hydrogen. The subject is of concern to the geologic community because of the
widespread use of precious metals as containers for H2O-bearing
materials and in conjunction with the use of various hydrothermal oxygen-fugacity
buffers. H2 diffuses through palladium-silver alloys very quickly,
through gold much more slowly. This data can be used to predict how long an fO2
buffer will be effective at a particular set of run conditions, and the minimum
temperature at which a given metal or alloy can be used as a hydrogen membrane.
Questions by Phelps Freeborn (2), George Helz, and Ralph Haugerud.
Fiske adjourned the meeting at 9:45 p.m.
There were 68 bodies in the room; no attempt was made to distinguish whether
they were waking or snoozing.
Respectfully submitted,
[signed Rosalind Helz]
The Geological Society of
March 26, 1986
The 1151st meeting of the Geological
Society of Washington was called to order by President Brett at 8:11 p.m. The
minutes of the previous meeting were approved as read. Election of one new
member, Craig Nicolson of the USGS, was announced. Robin Brett got right down
tot he two major themes of his presidency, duds and dues. He lamented that so
few members have followed his leadership in buying the GSW tee shirts, but
noted that they may still be ordered through Jane Hammarstrom. An agitated
Bruce Doe complained, "where is my tee shirt?" But our president
assured him that he would soon have it in time for the warm weather. Members were
again reminded of the present GSW fiscal crisis and urged to pay their dues
immediately, despite our inability to cash the checks as the treasurer is out
of the country. Janet Crampton, Chair of the Public Service Committee,
described the need for Science Fair judges this spring and warned us not to
leave without signing up for at least one of the Science Fairs.
Felix Chayes of the Geophysical Laboratory
gave the first talk, entitled "whatever became of descriptive
petrography?" His two slides showed the decline of mineral and
petrographic characterization of analyzed samples since 1920, although the
number of analyses reported has soared. Thus geologists are blazing a novel
trail out of the morass of specialization by learning less and less about more and
more. Petrologists are failing to provide descriptions of mineral assemblages
and modal analyses of the materials actually analyzed, while also failing to
analyze for or report data on multiple valence states (of iron) and volatile
contents. What is needed, says Chayes, is complete, unambiguous
characterization of analyzed specimens. Fussy, fussy, fussy. Questions by E-an
Zen, Bruce Doe, Joe Boyd, Phelps Freeborn, and Roger Nielson, who admitted to
being guilty as charged.
The second speaker, Daniel Jean Stanley
gave a talk coauthored with Harrison Sheng entitled, "Discovery of
Santorini volcanic ash in the Nile Delta: bearing of the Minoan eruption on
biblical exodus events in Egypt." Stanley explained that for many years he
has been studying sedimentary cores taken in the Mediterranean region usually
from shipboard, but this talk would focus on work in the Nile delta, near Lake
Mensawa, where cores are taken only along the roads so as to avoid setting off
the land mines planted here and there about the countryside. The authors
calculated that the coarse silt/fine sand fraction of the volcanic ash should
have been transported to the Nile delta region by the devastating first
eruption of Santorini 3500 years ago. Shallow drill cores taken there have yielded
several dozen shards which fit the Santorini geochemistry: the same SiO2
refractive index, SiO2 to TiO2 ratios, and within the
predicted size range. And there have been no volcanic eruptions in Egypt within
recent times. The ninth plague described in Exodus was "darkness so
intense that one can feel it, lasting for three days," and Stanley
suggested that this darkness may have been the ash fall from the Santorini
eruption. All 3 dozen shards, presumably. Questions by Dan Milton (2) E-an Zen,
Phelps Freeborn (2) and anonymous (2).
Julie Morris presented the third paper,
"10Be evidence for sediment recycling in island arcs." She
began by explaining why Be is an excellent sediment "tracker" in
subduction systems as it is produced by cosmic radiation in the upper
atmosphere, then deposited with rain and snow. The average surface sediment
concentration of 10Be is 5
billion atoms/gram. With half-life of 1 1/2 my, only recent subducted sediments
can be traced. High 10Be anomalies (3 million atoms/g) were measured
in lavas from Chile suggesting that sediments were subducted to depth in the
hot buoyant slab and transferred from the slab to the volcanic source. High 10Be
was measured in lavas from the Kuril islands where a great quantity of sediment
is fed into the trench. Intraplate and mid-ocean ridge lavas are depleted in 10Be;
for example the average MORB concentration is 0.5 million atoms/gram. By the
end of Morris' talk, there was not a Be skeptic in the house. Questions by Tony
Segovia, Dan Milton, Bill Hauser, E-an Zen, Robin Brett and a compliment from
Bruce Doe.
Eighty-one people attended this meeting
which was adjourned by President Brett at 10:10 p.m.
Respectfully submitted,
Margo Kingston
Geological Society of
Washington - 1152nd Meeting
April 9, 1986
President Brett called the 1152nd meeting
of the Geological Society of Washington to order at 8:08 p.m. The minutes of
the previous meeting were read and approved. Brett announced that he would quit
bugging people to buy G.S.W. teeshirts, but would continue to nag about paying
dues. Dick Fiske then announced that we need one more judge for the Montgomery
County science fair, and several guests were introduced, including David Smith
McGill of NBS, and Peter Johnson and George Varens(?) of JV Associates.
The first talk of the evening, by Robert
Wesson of the U.S.G.S., was on "Modeling the Rheology of Active Fault
Zones." He described the phenomenon of afterslip, as observed in
connection with the 1975 Oroville quake. Although the quake was quite large,
and the aftershock pattern defined a west-dipping normal fault, no surface
break appeared until several months after the quake. The fault was later
intersected by drilling, suggesting that this belated surface breakage was
indeed produced by slow creep on this same fault as the displacement from the
quake propagated slowly through a near surface layer of crushed and weathered
rock. Wesson illustrated this drilling with a shot of a drill rig, of which he
said, "I cannot tell a lie. This well is in South Carolina. I included it
because it seems to be important to show field stuff." Questions and
discussion, much of it skeptical, from Johnson, Tilling, Stewart and E-an Zen.
In response to harassment from Stewart and Zen about the paucity of data on
ground breakage immediately after the quake, etc., Wesson conceded, "I of
course would have preferred instrumental measurements and not to have to use
geologists." Typical seismologist. Moto Sato then received a much-needed
tutorial on basic elastic strain theory. The discussion closed when Keith
McLoughlin asked a seismology-type question, and received a seismology-type
answer.
The second talk, "Geology and Tectonic
Significance of the Ross Lake Shear Zone" was by Ralph Haugerud, U.S.G.S.
The Ross Lake shear zone separates the low grade Hozameen eugeosynclinal
sequence from the high-grade Skagit gneiss. The juxtaposition of dissimilar
rocks and metamorphic grades gives a very tight apparent thermal gradient
across the shear zone. Haugerud's preferred model for the area calls for
differential uplift, during the Eocene, to thin the intermediate thermal zones
and juxtapose the high and low-temperature ends of a Barrovian metamorphic
sequence, as opposed to blaming it all on accretion of contrasting terranes.
Questions by Walt Kavilius, Sorena Sorensen, Robin Brett, Eileen McLellan, Moto
Sato and E-an Zen.
The last talk of the evening, by Dmitri
Sverjensky of Johns Hopkins, was entitled, "A Model for the Origin of the
Metal Ratios of Sediment-Hosted Base Metal Sulfide Ore Deposits." These
deposits appear, from extensive evidence, to form when connate fluids, both
brines and hydrocarbons, migrate out of subsiding, compacting sedimentary
basins. The metal ratios in the subsequent deposits depend to a significant
extent on the nature of the rocks through which the brines migrate, with
Zn-rich deposits associated with carbonates, Pb-rich with reducing sandstones
and Cu-rich deposits with red bed-evaporite hosts. Questions by George Helz,
Moto Sato (2), Roger Stoffregen, Peter Johnson, and Robin Brett.
Brett closed with two announcements, and
adjourned at 10:03 p.m. The attendance was a sparse 53.
Respectfully submitted,
[signed Rosalind Helz]
Geological Society of
Washington - 1153rd Meeting
April 23, 1986
Vice President Fiske called the 1153rd
meeting of the Society to order at 8:04 pm. The minutes of the previous meeting
were read and approved. Tom Hoering then presented a visitor, Francoise
Becquard. Gene Robertson reminded all present of the May 3 GSW field trip. Jane
Hammarstrom reported that she had submitted orders for GSW T-shirts. The acting
secretary then read a series of announcements from Leanne Milton including the
news the Charlie Milton would be 90 years old on April 25.
Next E-an Zen delivered a short communications
on "Joints in Montana." The patterns of joints observed in glaciated
valley walls versus joint patterns outside glaciated regions in his study area
are different. This led Zen to suggest that some of the extra joints seen in
glaciated regions were produced by unloading 100 m of rock during glacial
erosion. He noted, however, that the inferred stresses involved were much
smaller than those needed to fracture rock under laboratory conditions.
A second short communications (why do they
come in pairs?) by Cyril Galvin addressed the problem of producing soot in
deep-sea sediments. It seems that marine clays from near the K-T boundary
contain little fluffy carbon particles, in addition to iridium, dead dinosaurs
and other debris. The carbon particles were duly cited in an article in Science
as evidence for worldwide forest fires at the time of the K-T extinctions.
Galvin showed pictures of black grunge on the beaches of New Jersey, which were
observed the day after the Garden State Racetrack burned down. Further
examination confirmed that the grunge was indeed soot, and that it occurred
downwind from the Garden State massive extinction. Galvin invited the audience
to conclude that it seems unnecessary to invoke worldwide forest fires to
explain the presence of a little soot in marine clays.
The first formal talk of the evening, on
"Vesicle and Olivine Phenocryst Distribution in Kilauea Iki Lava Lake,
Hawaii" was given by Margaret Mangan, U.S.G.S., Reston. She presented data
showing that vesicle and olivine phenocryst content declined in parallel in the
upper 30 m of the lake, as the molted lake degassed and the olivine phenocrysts
settled. Apparent settling rates for olivine are many orders of magnitude lower
than would be predicted from Stokes' law, an observation that led Mangan to
infer that the melt in the lake had the properties of a Bingham plastic, with a
finite yield strength, rather than those of a Newtonian fluid. Questions by Jo
Laird, E-an Zen, Felix Chayes, Warren Wood and Dick Fiske.
The second talk was "Acid-Sulfate
Alteration and Au-Cu-Ag Mineralization at Summitville, Colorado." The
speaker, Roger Stoffregen, began by quoting Mark Twain, who once wrote that
"A mine is a hole in the ground owned by a liar." Stoffregen neglected
to say whether the Summitville deposit illustrates Twain's maxim or not. What
the deposit does illustrate is acid-sulfate alteration, a relatively rare type
having alunite and kaolinite as alteration products, surrounding an intensely
leached core. This core, described by Stoffregen as the "vuggy silica
unit," is where the Au-Cu-Ag mineralization occurs. The mineralization is
there, hypothesized Stoffregen, because later hydrothermal fluids were
channelized into this very open, vuggy rock. The only comment was by Tom Dutro,
who rose to object to the use of the word "cartoon" in connection
with geologic diagrams and sketches, presumably on the grounds that they aren't
funny.
Anne Hofmeister gave the final talk of the
evening, entitled "Spectroscopic Determination of Thermodynamic Properties
of Olivine at Mantle Pressures." Hofmeister and coworkers have studied
phase transitions in forsterite bulk composition and tried to determine the
thermodynamic properties of all its polymorphs, the goal being to be able to
calculate the earth's geothermal gradient at great depth. The author fielded
questions by Ben Burton (finished his comment with "You're wrong"),
Robin Brett, Gene Robertson and Mary Ann del Marmol.
The meeting was adjourned at 9:40 pm.
Attendance was 65.
Respectfully submitted,
[signed Rosalind L. Helz]
GEOLOGICAL SOCIETY OF
WASHINGTON - 1154th MEETING
SEPTEMBER 24, 1986
The 1154th meeting of the society was
called to order by President Brett at 8:12 p.m. The minutes of the previous
meeting were read and approved as amended. Twelve guests were introduced. Four
new members were announced, and one of these, Phil Berger was present. As has
become the custom there were no informal communications, as President Brett was
presiding. After brief complaints and entreaties about this, Brett announced
that the evening's program would be especially entertaining to the
paleontologists, stratigraphers and eclectic petrologists in the audience.
The first talk of the evening, entitled
"Early history of the southern Oklahoma aulacogen" was given by
Charles Gilbert of the DOE. Located at the margin of the Texas craton [perhaps
the world's smallest craton], the aulacogen is a fault-bounded horst which
started out as a graben. Subsequent uplifting and erosion of this block exposed
layered granite and rhyolite sheets and underlying mafic rocks with cumulus
layering. Extension and tectonism accompanied the intrusion of the mafic
liquids. The geochemistry of the igneous complex is consistent with that of a
transitional tholeiitic rift zone. Gilbert contended that the Oklahoma
aulacogen would be an excellent site for deep drilling. For now, it is a good
place to enjoy a Permian landscape the way it really was. Questions by Tom
Wright (of NSP), E-an Zen, Doug Rankin and Dick Tolchin.
The second speaker, Bill Orr of the N.S.F.,
and a former student of Charles Gilbert, gave a paper entitled "Tertiary
stratigraphy of the Pacific Northwest". The primary goal of this study was
to interpret the paleoenvrionment of the Butte Creek area in Oregon where Oligocene
sediments are interdigitated with younger volcanic rocks. Orr proudly showed
slides of a Rube Goldberg type contraption, a mass of coiled rubber hoses,
swinging pails and metal pipes, which he used to obtain drill core. Butte Creek
sediments form a regressive sequence with shelf and high-energy marine deposits
overlain by dune deposits intertongueing with offshore sediments, and
non-marine sediments topping it all off. The ubiquitous fossil material ranged
from the outer neritic, through littoral, tidal and forest biofacies. For the
eclectic petrologists he described a talented echinoderm which could
discriminate ilmenite and magnetite from quartz. Questions from Tom Dutro,
Robin Brett and E-an Zen.
Steven Stanley of Johns Hopkins University,
gave the final talk of the evening, entitled "Evolutionary stability of
Neogene bivalve species". While waiting for the projectionist to get
organized, Stanley tossed out a few pearls of wisdom on the differences between
the punctuational and gradualistic theories of evolution. For this
beachcomber's dream study, Neogene and modern shells representing four families
are photographed, the images projected, and these planar shapes digitized. The
resulting stick figures yield nearly 43,000 individual measurements. It seems
the punctuational model best represents the evolution of these bivalves as they
zigzag through time. There is little change in 17 million years for some
lineages and some shells rare today were also rare in the past. Questions by
Peter Prinz, Ben Burton, Bill Hauser, E-an Zen and Phelps Freeborn.
Before adjourning the meeting, President
Brett describing a letter from a past Bradley Award winner who praised the
wonderful taste of beer drunk from the Tiffany silver Bradley cup. The meeting
was adjourned at 10 pm. Seventy three persons attended.
Respectfully submitted,
[signed Margo Kingston]
Geological Society of
Washington
1155th Meeting
October 8, 1986
The 1155th meeting of the Society was
called to order by President Brett at 8:06 pm. The minutes of the previous
meeting were approved as read, and several guests were introduced, including
Tod Lenagh, Bill Wycoff, George DeNeve, Jill Nesterly, and Sergee Jostikov (sp.
uncertain). Brett then announced that we (GSW) were at war with the Cosmos Club.
Brett had refused to pay the full projectionists' fee for the previous meeting,
because of the man's utterly abysmal performance. The club in turn did not
bother to provide a projectionist at all for the October 8 meeting. Phelps
Freeborn volunteered to man the projector, and did an excellent job. (But will
Brett pay him? Don't bet on it.)
Brett then asked if there were any informal
communications, and, when informed there were none, said "Oh, that's
right. I'm in town." Where had he thought he was?
The first formal talk of the evening, by
Melville Dickenson of VPI, was entitled "Iron Redox Equilibria in
Peraluminous, Metaluminous and Peralkaline Silicate Melts." Dickenson has
studied the variation of the ferric/ferrous ratio with melt composition, and finds
that ferric iron is stabilized in peralkaline melts, while ferrous is stable in
metaluminous and peraluminous melts, at constant SiO2 content and
oxygen fugacity. The solubility behavior of other components, such as P2O5,
TiO2 and ZrO2 also depends on whether the melt is
peralkaline or peraluminous. This clearly-delivered talk elicited much
discussion, with questions from Ken Towe, Moto Sato, E-an Zen, Dick Tollo, Bill
Hauser, Zen again, Phelps Freeborn, George Helz, and, again, Sato. In response
to one of Zen's questions the speaker replied that as far as he was concerned
"boron can do anything it wants to do."
The second speaker, Scott Wing of the
Smithsonian, spoke on "Interaction of Vegetation and Sedimentation."
The speaker, invited by President Brett to give his own vita, informed us
"I was born in a log cabin and the reason I'm not in American Men and
Women of Science is that I'm neither." (Is the Cosmos Club ready for
this?) Moving on to his talk, he pointed out that two patterns of vegetation succession
could be observed in the modern environment: In the first type, one plant
community supplants another, each community modifying the environment in ways
that favor its eventual displacement. In the second type, exemplified by bald
cypress swamps, the plants modify the environment in ways that prevent other
plants from moving in. This happened in the Eocene, too, according to the
speaker. The normal, progressive type of plant succession is shown by the
Willwood Formation in N.W. Wyoming. Further east, in the Bighorn Basin, one
finds thick coals, formed in stagnant backwater swamps, by retrograde veggies
of the second type. Some things never change. Questions by Mike Peruker, Ken
Towe, Bill Hauser, and of course, E-an Zen.
The last speaker of the evening, Randall
Parrish of the Geological Survey of Canada, addressed us on "U/Pb zircon
geochronology - new techniques, et cetera" in preference to the topic
listed on the written announcement. Parrish began by saying how glad he was to
be in Washington, DC, home to John Wesley Powell, one of his lifelong heroes,
and also to world-class zircondater Tom Crowe. He declared that zircon is the
world's most interesting mineral, a fact hitherto unknown to many of us, and
proceeded to make a surprisingly good case for it. Basically, once a zircon
crystal forms, it remains a closed system, so that isotopic ratios produced by
radioactive decay of various U isotopes are never reset, unless the crystal
dissolves completely. New techniques, allowing investigators to date parts of
complexly zoned crystals, enable them to get ages of protoliths, metamorphic
events, shearing, etcetera. Zircons have total recall. Questions by Sorena
Sorensen, Gene Robertson, somebody who sat next to Gene Robertson, Dick Fiske,
Moto Sato, Robin Brett, and Hatcher (?).
Brett then told the membership toe were in
good financial shape, announced the next meeting, and adjourned at 9:55 pm.
Attendance was 63.
Respectfully submitted,
[signed Rosalind Helz]
Geological Society of
Washington - 1156th Meeting
November 5, 1986
The 1156th meeting of the society was
called to order by President Brett at 8:05 P.M. Minutes of the previous meeting
were read and approved. Two new members were announced and one guest, Jeff
Tuttle was introduced. President Brett reported the death of GSW member, Wayne
Sigleo. Attendees were reminded of the up-coming Piedmont GSW field tri p to
the Alexandria-Occoquan Piedmont led by Avery Drake. Hopefully the IRS was not
listening as Brett advised members that to pay future GSW dues this year [with
the idea of deducting it on 1986 returns] may be illegal but urged us to do so
anyway. Brett next took on the Cosmos Club. Due to sloppy Cosmos visual-aid
services society members will now do the projecting at meetings, and save money.
Volunteers were solicited. Bribes were mentioned. Brett next questioned if the
recent low attendance at meetings was due to the current officers, parking
anxiety or those awesome miles stretching between Reston and the Cosmos Club.
Nobody mentioned the beer.
E-an Zen leaped to the podium and presented
the first informal communication with President Brett presiding. Zen spoke
about S and I granites, aluminum and cordierite. He stated that the absence of
cordierite in peraluminous granites may not mean that the granite is not
S-type. Cordierite formation depends on the iron to magnesium ratio, the degree
of hydration, oxidation, and sulfidation as well as alumina saturation. Dave
Stewart asked a question.
Startled by this surprising short
communication, President Brett awarded the first formal speaker, Eric Sundquist
an 8 year post doc appointment in his introduction. Sundquist, whose talk was
entitled "fossil fuel carbon dioxide in a geological context" secured
the attention of his audience by stating right off that there are megabucks
available for the study of the partitioning of CO2 between oceans,
atmosphere and the biosphere.
Sundquist discussed results of his earth,
air and water modeling to determine the carbonate horizon saturation and flux
at the sediment/sea water interface. He stessed the important contributions
geologists can make in this type of interdisciplinary study because of their
understanding of carbonate distribution through time as well as the disparity
between geotime and the sort span of anthropogenic effects. Questions by Dave
Stewart, Phelps Freeborn, Robin Brett, Dan Milton, Ben Burton, Janet Crampton,
Doug Rumble and George Helz.
Second speaker, Craig Nicholson began his
talk entitled "The North Palm Springs earthquake of July 8, 1986" by
claiming that his slides were all wet, due to the heavy rainfall, that is, not
their content.
This earthquake caused localized surface
deformation, such as rock falls, slumping and ground cracks to the tune of $6
million damage. Compressional features occurred complimentary to tensional
fractures but there was little true tectonic displacement. Surface damage was
not tectonic because rupture was at depth and probably occurred on the Banning
fault, not the Mission Creek fault, site of most damage. It had been assumed
that the 1948 earthquake was located on the Mission Creek fault but modern
seismic studies put it between the two faults. In southern California they play
epicenter hide and seek. Questions by Moto Sato (2), George Helz and Robin Brett.
Craig Dietsch gave the final talk of the
evening, entitled "hornblende 39Ar/40Ar age-spectra
from high-grade rocks of the polymetamorphic highlands of western
Connecticut". His study area, the Waterbury dame is among the largest is a
series of domes within the Conn. River Valley. A decollment separating two
major tectonic levels is exposed in this dome, but isograds are not coincident
with the decollment. It seems hornblende collected above the decollment gives
concordant spectra, and a good approximation to the age of metamorphism. Other
horneblende is not so well behaved, yielding extremely discordant ages probably
because extraneous argon is accumulated in retrograde events. This study has
important implications for conventional argon dating, but Waterbury makes a
person cynical despite the beautiful kyanite so Dietsch is ready to move on to
more "normal" things.
Questions from Dan Milton who asked Dave
Stewart's question, Eileen McLellan, Serena Sorensen , E-an Zen (2), Ralph
Haugeraud and Dave Stewart who thought of another question.
President Brett thanked Phelps Freeborn for
leaping into the breech and running the projector. Announced the new slate of
officers and invited other nominees to run against these worthies at the next
meeting.
The meeting was adjourned at 10:08.
Attendance was 60.
Respectively submitted,
Margo Kingston
THE GEOLOGICAL SOCIETY OF
WASHINGTON - 1157TH MEETING
DECEMBER 3, 1986
President Brett called to order the 1157th
meeting of the Society at 8:10 P.M. Four new members, Kurt Panter, Royce
Hanson, John Montague and Helen Long were announced, and one visitor, Randy
Kusky, was introduced. An enthusiastic Dick Tollo gave us a preview of the
report of the Best Student Paper Committee by describing the Committee's
revitalization. As there were no further announcements nor informal
communications, President-Elect, Dick Fiske, commenced his illuminating
introduction of Robin Brett, as a South Australian émigré who burst forth from
the University of Alidade (that's antipodal jargon for the University of
Adelaide) to the laid back Harvard of the 60's, then on to a number of scenes
in Washington, Texas and Reston, and finally to this esteemed podium.
President Brett began his Presidential
address entitled, "Volcanoes, sulfides and fluids from the Southern Juan
de Fuca Ridge: a consortium approach", by describing how his interests
shifted naturally from the Apollo Program to the inhospitable briny deep
because he likes the consortium approach to solving geologic problems. After a
brief plug for the upcoming JGR issue which will be devoted to the Juan
de Fuca Ridge study, Brett outlined the project strategy: all available
exploration tools are used to define the ridge before making a dive. Different
cruises focused on a variety of anomalies associated with this system.
But, why travel to the cold, fog, and rough
seas off the Oregon/Washington coast when we have all that stuff right here in
D.C.? Brett's answer: that the Juan de Fuca ridge has an active hydrothermal
system which may be analogous to older ore-forming systems. Although this ridge
does not have a rapid spreading rate, the extrusive rocks are sulfide enriched
and have a significant economic potential. Moreover, the ridge is entirely
within the U.S. exclusive economic zone. The glassy extrusive rocks contain
clinopyroxene, plagioclase and olivine, but no pelagonite. They have no
manganese crust and no sediment covering. Topographic highs are concordant,
with high temperature anomalies. The ridge was mapped using a variety of geophysical
methods including bathymetry, magnetics, gravity, heat flow, water temperature,
echo sounding, VCR imaging, and photography. Video sweeps covered fifty yard
swaths over 10 square kilometers. The magma chamber was delineated by
multichannel seismic measurements. Beneath the waves lies a lava plain composed
of multiple asynchronous flows which surround a nested graben bounded by en
echelon faults. Collapse piles increase near the 5 or 6 hydrothermal vents
which occur in the central cleft.
Just as Brett got to the good part, where
he was describing geologic traverses in the Alvin as comparable to traveling
through utter darkness in a broom closet with a small window and a flashlight;
suddenly our president was interrupted by a member of the consortium, Ellen
Kapell, who wanted to provide more detail on a subject two slides back. It is
the custom to not ask questions after the Presidential Address, but there is no
precedent about setting the president straight during the course of his talk.
Continuing with adventures in the Alvin,
Brett pointed out that because the submersible can be navigated, it is possible
to do geological mapping as well as to collect samples. With the help of
excellent slides we journeyed through clefts dodging rock debris and aa-like
flows. Close to the vents lurk what Brett described as furry/fuzzy rocks along
with meter-sized crabs, and worm tubes which Brett initially claimed were up to
70 m in length! This estimate was subsequently revised to 7 m. Orthogonal
chimney-like forms composed of sulfides loom in this murky landscape. Often,
very fine dust obscures some of these wondrous features. Minerals collected
near the vents include anhydrite, barite and margarite. There are two types of
sulfides, those high in copper and zinc-rich; and, porous sulfides. Some vacant
worm tubes bulge with marcasite and pyrite. A new mineral, a
Zinc-sulfur-Clorohydroxide, was collected by Brett and studied by Howard Evans.
The chemistry of this place is of course bizarre; the pH of the plume site is 3.2
and chlorine is high, precipitation at the plume is due to pH and temperature
changes, as well as saturation.
All too soon our journey beneath the sea
came to an end. In deference to custcan, there were no questions. President
Brett adjourned the meeting at 9:25 P.M., and despite his subjecting the
audience to all that water, the approximately 120 thirsty attendees rushed to
the refreshment table.
Respectfully submitted
Margo Kingston
Recording Secretary
MINUTES OF THE 94TH ANNUAL
MEETING OF THE
THE GEOLOGICAL SOCIETY OF WASHINGTON
DECEMBER 3, 1986
Believing that members had recovered from
the Presidential address and were well fortified against the rigors to come,
President Brett called this raucous gang to order at 9:50 p.m. Before Brett
could get in another word, Dick Tollo rushed the podium with his committee
report but was firmly blocked by our president. Brett attempted a proper start
again, but the meetings secretary tried an end run to get in her report first.
No chance, because above all we follow Robert's Rules here. With calm finally
restored, Rosalind Helz read the minutes for the 93rd Annual meeting. These
were approved. The report of the meeting's secretary was decorously read. In
the next report, Council secretary Helz gleefully told us that although only
50% of the council attended any of the three meetings, they were an effective
bunch. They eliminated the finance committee and arranged for GSW to sponsor
Leanne Milton's teaching guide while the Smithsonian put up the money.
The Treasurer's report was read by Brett
because Klaus Schultz had just left town. There must have been other reasons
for his flight because the GSW financial situation had improved as a result of
a dues increase and reduction of expenses. Suspicion rose again when the
chairman of the auditing committee, Harvey Belkin, also failed to show. But the
books were in order and the Treasurer was commended.
Membership chairman, Fred Simon, reported
that we lost only a few members in 1986 despite the dues increase. There was an
increase in retired members. These mellow folk appreciate fiscal
responsibility.
Leanne Milton reported on the status of the
pre-College education committee. Reportedly she caused 30,000 lbs of rocks to
be moved from the USGS, making her the equivalent of a small glacier. Perhaps
that explains the recent shifts and rebound in Reston. Geology day at a local
Nature Center and the Naturalist Center at the Smithsonian also benefited from
her efforts. Janet Crampton, Chairwoman of the Science Fair Committee, reported
that 8 fairs were judged in a marathon series from mid-March through mid-April.
Finally, Dick Tollo gained the podium with
his report on the College Student Award committee. The undergraduate research
award had been revitalized and he was optimistic about its benefits in setting
youth on the right track. There were no takers in 1986.
Gene Robertson reported on the work of the
Centennial Committee. There were 29 founders of the society, all eminent
scholars and authors of classic papers. Such a level of excellence should
motivate college students and energize us all.
When
chairman of the Awards Committee, Steve Huebner, took the podium, waves of
nervous tension swept the room. After noting that some of the scheduled papers
should have been informal communications, Huebner announced that there were
twin Great Dane awards for best actual informal communications. The honored
recipients were acid rain foe, Bruce Doe, and Van Zen of the Montana joints.
This committee sought to stimulate more informal communications by presenting
two prizes. So far it looks like they lost on that one. Then came the Bradley
prize announcements. The second best paper prize was also awarded to two, Julie
Morris of 10Be fame and Charlie Gilbert of the OK aulacogen corral.
Was this committee seeing double? It's fortunate that the society was in the
money the way they were throwing the bucks around. These prizes have price
tags. Steve Stanley stood alone at the top as winner of the first prize
for his paper, "Evolutional Stability of Neogene Bivalve Species,"
which indeed combined scientific excellence with some interesting controversy.
The 1986 embodiment of Sleeping Bear, Roz
Helz, put on her third hat of the evening and displayed her raconteur skills.
She revived the audience with yarns of the astonishing past of this gentrified
cup and other GSW tribal myths. We were vividly reminded of the many moments of
hilarity unconsciously provided by several speakers. The old pros in the
audience sporadically supplied some comic relief too. But this committee was
after a fresh display of "rarefied, goodnatured, fangless jollity."
And what should happen? Cherchez the geophysicists. All this time
paleontologists and geochemists have been embrace in an all consuming rivalry
for science and wit, when its the geophysicists who were having all the fun.
And so in the end, Rob Wesson was bestowed winner of the Sleeping Bear award
and all it entails.
President Brett read the slate for 1987
which was accepted by acclamation. Before handing over the gavel, he thanked
all who had worked for GSW during his tenure and confessed that his greatest
achievement while in office was leaving behind a "more submissive"
Cosmos Club. Newly elected President Dick Fiske presented the new officers and
adjourned the meeting.
Respectfully submitted,
Margo Kingston