GSW: 1980
MEETING MINUTES
Geological Society of
January 9, 1980
The 1060th meeting of the Society was
called to order by President Prinz at 8:01 p.m. The minutes were read and approved.
Five visitors were introduced to the group, and Prinz announced that Pete
Toulmin will be the new Program Chairman for the Society.
The first speaker of the evening, P. E.
Hare, of the Geophysical Laboratory, gave an excellent discussion of the use of
amino acid geochemistry for estimating fossil ages and diagenetic temperatures.
Use of the amino acid techniques in Spirzbergen has shown the practical
application of these methods for field research. Questions were posed by G.
Helz, Roedder, Sohn (2), Dutro, D. Milton, Zartman, Tracey
and anonymous.
Following this talk, Lina Echeverría, of
the Carnegie Institute, delivered a fascinating account of modern komatiites on
The last paper was given by David Wones of
Virginia Polytechnic Institute (and former President of the Pun Society of
Washington). Dave described studies of the Norumbega fault zone, eastern
Attendance was 132 and the meeting was
adjourned at 9:50 p.m.
Respectfully submitted,
John R. Keith
Acting Secretary
Geological Society of
January 23, 1980
The 1061st meeting of the Society was
called to order by President Prinz at 8:06 p.m. The minutes were read,
corrected, and approved. Five new members were welcomed into the Society; four
visitors were introduced.
Several announcements were made, including
the warning that dues notices will be about four weeks late because the
membership list is being computerized. In addition, President Prinz solicited
information about the meetings and other activities of other geological groups
in the area so that such information can be compiled and posted at our
meetings.
President Prinz reported that Joe Boyd,
recent past-president of the Society and last year's program chairman, was
seriously injured in a traffic accident the previous week.
Finally, the secretary made the traditional
annual appeal that questioners please identify themselves and is gratified to
report that several unheard-from questioners, notably Messrs Joe Zilch, Brian
Monster, Joe Blow, and Melvin Kleinbaum, emerged from anonymity to enliven the
proceedings.
There followed an informal communication by
Charles Milton, describing a new occurrence of the green nickel-bearing
mineral, Pecoraite, in small calcite geodes from near
A second informal communication, by Greg
Sohn, dealt with his method of distinguishing younger ostracodes contaminating
older sediments: The organic framework of younger ones persists as identifiable
replicas after the ostracodes are treated with dilute acid. Showing slides of
bristly and bristle-free ostracode appendages, Sohn cited a specific case where
interstitial Candonidae ostracodes of Pleistocene age had been collected and
identified in Ordovician sediments. Question by Berdan.
The first paper of the evening was
presented by John M. Edmond of MIT on "The chemistry of the 350°C
Edmond characterized the sea floor as drab
"like the moon" except where the hydrothermal springs provide energy
both as heat and in reduced elemental species available for nourishment of
bacteria, which constitute the food supply for other organisms.
Colorless, sulfate-free spring water, with
a temperature of 350°C and pH of less than 4, streams from orifices, many as
small as 3 cm in diameter, in constructional chimneys extending as much as 9 m
above the sea floor. Mixing with ambient sulfate-bearing sea water, with an
average temperature of 2°C and pH about 7, causes precipitation of iron-,
copper-, and zinc sulfides in black plumes up to 30 m in height. In total
concentrations up to 1 g/liter, chalcopyrite and sphalerite predominate in the
plumes, with little pyrite present. The vents contain substantial amounts of
anhydrite and sulfide minerals which, with collapse and filling, often form
sulfide conglomerates.
Questions by Robbins, Roedder, Zen, Jones,
Robertson, and Sato.
In the second paper, "Competitive
interaction in the fossil record: are clams and brachiopods an example? are
there any examples? ," Stephen Jay Gould of
Comparing the number of genera of
brachiopods and clams in the Treatise on Paleontology for ninety-six time
periods, the speaker defined by computer two patterns of occurrence: That of the Paleozoic before the Permian
extinction, when brachiopods outnumbered the clams, and that of the
post-Paleozoic, when clams expanded and flourished, while brachiopods declined.
Within each of the two periods, there was positive correlation, although not
without some scatter of data-points: When one group did well, so did the other,
even though their relative proportions did change. In other words, conditions
that favored one group generally seem to have favored the other as well.
With a paean to J. Harlan Bretz, whose work
in the channeled scablands established catastrophe as a legitimate alternative
among geological interpretations, Gould reminded the audience that success of a
group of organisms during a debacle, such as the Permian extinction, does not
necessarily indicate superiority under more "normal" conditions. He
cited "flexibility of architecture" among the clams as a
"pre-adaptive accident of history" which permitted such modifications
as the fusion of the edges of the bivalve mantle to form the siphon,
modifications that made it possible for certain types of clam to burrow of
otherwise adapt and occupy new environments.
Gould concluded that a Darwinian approach
may apply well in studying local populations, but that uncritical extrapolation
to inter-species situations may well be misleading. There is, in fact, no
evidence of any interaction between brachiopods and clams, much less of
disruptive or destructive impact from competition.
Questions by Dutro, Chayes, Zen, Hickey,
Kauffman (4), G. Helz, Roedder, Towe, Yochelson (2), and Gordon.
Attendance: 164.
The meeting was adjourned at 10:20 p.m.
Respectfully submitted,
Cristina C. Silber
The
Geological Society of
February 13,
1980
The 1062nd
meeting of the Society was called to order by President Prinz at 8:05 p.m. in
the John Wesley Powell Auditorium. The minutes were read and approved after Ed
Roedder bemoaned the fact that his alter ego, Joe Zilch, though mentioned, was
not credited with specific questions.
As the
Council did not meet. there were no new members to welcome. Eight visitors were
introduced:
Tren
Hazleton USGS
Emi Ito Department of
Terrestrial Magnetism
Kim
Kahouski (sp?)
Richard
Williams
Peter
Mollock (sp?) USGS
Dr. Goto
Peter Guth formerly of MIT, now
at
Betty
London
David
London USGS
There were
two announcements, one by the President that Joe Boyd is recovering well and
will welcome visitors at
In the
only informal communication of the evening, Charles Warren, of the USGS,
described the emplacement by glacier of huge marble boulders in
Robert
Mattick presented the first talk of the regular program, a multidisciplinary
study of "Geology and petroleum potential of the Atlantic Coastal
Margin." The speaker related the stratigraphy from drilling on the Scotian
shelf, which reflects five stages in the evolution of the Atlantic Ocean, to
the entire region, then focused on prospects in an area 3 miles square off
Of 19
exploratory wells, 16 were dry, 2 had shows of gas at 14,000 feet, and one had
shows of gas and oil at 8000 feet, with a test flow of 630 barrels of oil per
day.
Seismic
exploration indicated possible structural traps as well as four
potential-reservoir-rock facies, which were confirmed by geochemical analyses.
Maturation of their organic content was evaluated by pollen, vitrinite
reflectance, pyrolytic decomposition, and carbon preference index. Mattick
summarized this data by saying that there is low probability of oil generation,
but good likelihood for gas.
Questions
by McKelvey (2) and Hewitt.
The second
paper was "Geological pressure determinations from fluid inclusion
studies", presented by Edwin Roedder on behalf of his coauthor, R. J.
Bodner. The use of fluid inclusions as geothermometers for understanding
conditions of crystallization has evolved since Henry Clifton Sorby's interest
began in the mid-19th century, based on the assumption that each inclusion
begins as an homogeneous fluid at the time of entrapment, though it may be a
crystal, gas, liquid, or combination of the three under present
conditions. Using a heating stage, it is
possible to re-homogenize the contents of an inclusion, establishing a minimum
value for the temperature at the time of crystallization.
The
temperature of homogenization defines a range of possible pressures at the time
of entrapment. The relations of pressure versus temperature can be plotted,
establishing isochores, from which we can set the upper and lower limits of
pressure.
Attempts
to Pinpoint temperature and pressure are complicated by other variables,
particularly the composition of the inclusion, coexistence of inclusions of
different composition, and the possible influence of subsequent geologic events
on the inclusion-bearing minerals. For example, if an inclusion contains sodium
chloride, its exact composition must be determined because the slope of the
isochores varies for different concentrations of sodium chloride.
With words
of caution against inadequate experimental data and the flawed interpretive
methods of some other workers, Roedder tantalized the audience with references
to geological case histories, such as the inclusion of steam and liquid
water in the Bonanza cassiterite ore. He concluded the talk by summarizing the
prerequisites for use of inclusions in geobarometry:
1-detailed
petrographic work
2-
composition of -the inclusion, or inclusions
3-good
PVT-X data.
From Sorby
to Sherlock Holmes to Roedder and Bodner, the contemplation of minute bits of
evidence makes the case.
Questions
by Robertson, Warren, Hewitt, French, and Toulmin.
The final
paper of the evening was "Rapids, mudflows, and hydrologic change in the
While
refuting Leopold's assertion that the rapids result from channel bars, the
speaker acknowledged that a few such bars exist, consisting of better-sized,
better-sorted, and more rounded sediments than those in the fans.
The
second, much less common, cause of rapids is landslide or rockfall direct from
the
Mudflows
are another phenomenon in the side canyons and the
Schaffer
cited W. L. Graf's calculations for the Green River in
As a final
note, Schaffer offered an explanation for the formation of the Grand Canyon:
According to a chauvinist from
Questions
by Prinz, Stifel, Zen (2), and Roedder.
The
meeting was adjourned at 10:14 p.m. Attendance was 114. $32.90 was collected
for beverages.
Respectfully
submitted,
Cristina
C. Silber
Geological Society of
February 27, 1980
President Prinz called the 1063rd meeting
of the Society to order at 8:07 p.m. After a correction from Vince McKindness,
the minutes were approved. The election of one new member, Deborah Hamill of
AGI, was announced. No one admitted to being a visitor. There were
announcements and good-humored comments on several topics, none of which bear
repeating. Eat your hearts out, posterity!
Ian MacGregor presented the first talk,
"Geothermometry and geobarometry from mantle samples", co-authored by
F. R. "kimberlite" Boyd and A. A. Finerty. As the title suggests, the
paper dealt with the stability range of ultramafic socks in terms of temperature
and pressure.
After a review of known relations of
composition and temperature for several assemblages, the speaker applied the
information to ultramafic xenoliths from kimberlite pipes from five locations
that lie in a progression from the center outward in the Kaapvaal craton in
In an interesting application of the
principles and relations described, including such refinements as the effect of
chromium in clinopyroxene, the authors described the petrography of
pyroxene-spinel-olivine rock with reaction rims. The rim composition represents
the flow of kimberlite, and three steps in the origin of kimberlites can be
deduced from the data:
1 - a solid diapiric phase, preserved in
the sheared samples;
2 - partial melting as the kimberlite liquid
rose toward the surface; and
3 - fluidized magma with vapor.
Question by Zen.
The second paper was by John B. Robertson
on "Geological and hydrologic aspects of low-level radioactive waste
burial." The
The eight existing disposal sites are of
two types, two "arid-zone" ones in areas where rainfall is 4-17
inches per year and 6 "humid-zone" ones in areas where rainfall is
35-50 inches. Basically, all the sites are holes in the ground where wastes in
a variety of containers are dumped and covered with dirt. The USGS has been
studying the dumps to determine what the fate of the radionuclides in them is
-- considering factors such as hydrologic properties of the site; trench-water
chemistry; water-rock interaction; and ground-water transport. EPA and other
concerned parties will use the findings to help set regulations for existing
dumps and select sites for new depositories as the need arises.
Robertson catalogued the existing sites,
their history of opening and closing; their geological setting; their floods
and collapses; the discovery of extra unrecorded wastes between known trenches;
and other unsettling findings. Through it all, he maintained a cheerful
attitude and arrived at reassuring conclusions: Humid sites pose more problems
than dry-zone ones -- all six of the former show migration of nuclides from a
few feet to a couple of hundred feet -- but all can be prevented by better
engineering and more careful bookkeeping without much additional cost. At
present, it costs $7-8 per cubic foot minimum -very cheap for perpetual
storage! Unlike
Questions flowed from Stewart (4), G. Helz
(2), Roedder (4), Jones (2), Chuck Wood, Zen (2), Toulmin, Douglass, Back,
Schoellkopf, and a dashing anonymous chap in a blue plaid shirt.
The final presentation was by Maria Luisa
B. Crawford on "Applications of fluid inclusion studies to metamorphic
rocks." In metamorphic rocks, rock composition controls the composition of
inclusions, while the opposite is true in igneous ore deposits.
A further contrast between fluid inclusions
in igneous rocks and those in metamorphic rocks is that the latter are
miniscule -- usually less than 10 microns in diameter -- and sparsely
distributed. Often several types of inclusion coexist in a given sample, each
type containing a different fluid and representing a different event in the
metamorphic process. This variety of compositions makes crushing of samples and
determination of bulk chemistry ambiguous and effectively meaningless.
Crawford and her students, using the
heating-freezing stage, find two groups of fluids: Aqueous ones consisting of
water plus salts -- very few contain pure water -- and ones that are rich in
carbon dioxide, perhaps also containing hydrocarbons -- not necessarily
methane, as is usually assumed, but possibly ethane, propane, or butane.
Seeking composition -- at the point of
melting of crystal(s) to liquid -- and density -- at the point of
homogenization of vapor and liquid, the speaker called for more and better PVT
data and definition of phase relations of solids versus liquids in the freezing
range. The same density in different inclusions indicates contemporaneity of
formation.
For inclusions in calcareous assemblages,
Crawford has collected samples from
Most inclusions in metamorphic rocks occur
in quartz and contain no carbon dioxide at all. Salts are usually assumed to be
chlorides, but may, of course, be bromides. The presence of calcium, magnesium,
and sodium salts may be distinguished by determining the initial melting
temperature: A low one, in the range of -57 to -60°C, indicates pure NaCl,
while -21°C is about the lowest for the divalent salts.
Yet another aspect of the study is
examination of calc-silicate rocks from
In conclusion, Crawford urged that
thermodynamic studies and. speculations should not assume pure water. She
emphasized that original .rock fluids occur in only 5 percent of inclusions in
metamorphic rocks and that later inclusions contain fluids of different
compositions. She proposed as the relation between retrograde metamorphism and
higher salinities that the longer a fluid remains in contact with a rock, the
more it is enriched in salts.
Discussion and questions by Jones (2),
Roedder (3), Sato (2), Stewart (2), Zen, and Rumble (3).
The audience stampeded to adjournment at
10:22, leaving the President announcing to the secretary the program for the
next meeting. Attendance was 88. Collection for refreshments $15.50.
Respectfully submitted,
Cristina C. Silber
The Geological Society of
March 12, 1980
The 1064th meeting of the Society was
called to order by Second Vice President Penny Hanshaw at 8:20 p.m. after a
delay to get all the equipment working -- lights, pointer, microphone, sound
system for the movie projector. The minutes of the last meeting were approved.
There were no new members to announce, but three visitors were introduced:
William Cassidy of the
Louis Rancitelli of Battelle Memorial
Institute
Jon Annexstad of the
Bevan French announced the unusual
occurrence that the rings of Saturn were lined up on end even as he spoke.
The Secretary made an announcement about
beer and finances, noting that we pay out to the Cosmos Club twice as much for
beer and coke as we take in donations. The Council requests that we members
please GIVE: or face the loss of out-of-town speakers, a rise in dues, or
further harassment by the Secretary...
Professor Cassidy of
Questions by Silber, Toulmin, Hewitt, G.
Helz, Stifel, Wood, and a comment by French.
The first formal presentation of the
meeting was a multi-media extravaganza by Sigmund Snelson called "Dynamic
continents: A computer animation of Phanerozoic plate motions." The piece
de resistance was an 8 1/2-minute movie covering 5 1/2 million years by
Christopher Scotese and the staff and computers of the Shell Company. Snelson
narrated the sequence of events as the enthralling history of plate movement
occurred be fore our eyes. With seeming inevitability, the land masses swirled
across the globe to fulfill their destiny (:) in an unified Pangaea, surrounded
by the
Many disciplines have contributed to the
film, including studies of faunal distribution, paleoclimatic data, polar wandering
curves to get rates of movement, and, of course, paleomagnetic data. The
problem of which models to select remains a challenging one: The Caribbean and
Another set of problems concerns how to
handle submerged land masses, the rise and fall of sea level, the changes in
shoreline and continental shape. The present film portrays the land masses in
their present outlines in the interest of having viewers recognize them; thus
the western portion of
Computer modeling, such as Snelson
presented, further-elaborated, could test theories of expanding earth through
time. One exercise already undertaken was to extend present motions 50 million
years into the future: Buy up cheap waterfront property today, the speaker
urged. The film is available without charge from the Shell Film Library in
Questions by Cassidy, TD. Milton, French,
Toulmin, Foose, ?en (2),
In his talk, "Carbonate turbidites of
the eastern Venezualan Eocene", Professor N.G. Muñoz presented a detailed
description of the stratigraphy in two areas of
Near the center of the north shore of the
island, there is a sequence of carbonate rocks, from calcilutites to
biocalcsiltites to reef-derived coarse bioarenite. Some beds are characterized
by parallel laminae, coarser at the base; others by convolute laminae. Worm
tracks are present at the top of the beds, and worm tubes consisting of coarser
sediment reworked from deeper in the section mark the fine-grained upper
surfaces of some beds. Interbeds show fine parallel laminations characteristic
of bottom--current deposits with micro-cross-lamination and micrograding in
thin section.
Paleocurrent measurements show north and
south sources for the reef-derived sediments which were deposited in the
western half of the 18-kilometer-wide trough reaching depths characteristic of
the lower continental rise. In the eastern half, the trough had no fringing
reefs, so the presence of reef-derived sediment suggests reworking and
transport of the sediments from the west.
Questions from Stokowski, Towe, Silber.
The final talk of the evening was by Alan
M. Gaines on "Dolomitization kinetics: Recent experimental studies."
The fact that vast deposits of dolomite are not forming in the present as they
did in the past represents an exception to the principle of uniformitarianism.
While calcite and aragonite are actively forming and are well-documented, the
first modern reference to sedimentary dolomite appears in the literature in
1957.
The crystal structure of calcite consists
of layers of calcium and carbonate ions; in stable dolomite, every other
calcium layer is replaced by magnesium, which changes the structure and results
in more x-ray reflections.
High temperature results in thermal
disordering among carbonates. 1180°C represents the highest temperature where
dolomite is evidently ordered; calcite continues to be ordered at higher
temperatures.
Stochiometric dolomite is stable in
sea-water; aragonite is not stable at 0°C until 3 kilobars. Yet, in sea water,
we find aragonite and high-magnesium calcite most commonly, low-magnesium
calcite less so, and stable dolomite least of all.
Calcium-magnesium carbonate exists as solid
solutions with Mg ranging from 7 to 40 mole percent, but the resulting
compounds are not ordered. The speaker pinpointed ordering and stability as
keys to the dolomite problem, acknowledging that we do not understand the
origin of dolomite, nor why it does not form when it should.
Studies of modern dolomite and ancient
analogues show that it forms by recrystallization of pre-existing calcite. It
is not .possible, according to Gaines, to produce cation-ordered dolomite
experimentally below 100°C at atmospheric pressure, so application of experimental
results to natural low-temperature conditions is impossible.
Nevertheless, the speaker and others have
done experiments based on the equation solid calcium carbonate molecules plus
magnesium ions in solution yields solid dolomite plus aqueous calcium ions.
He used highly concentrated starting solutions
of 2 molar Ca + Mg, and relied on x-ray work to establish both the extent of
the reaction and the crystallographic consistency of his experimental products.
Attenuation of ordering reflections was similar for both natural and
synthesized dolomites, and peaks were sharp.
Kinetics in the system are
temperature-dependent because of high activation energy. The speed of reaction
depends on the starting material: Fastest for aragonite, next for
high-magnesium calcite, Slowest for low-magnesium calcite.
The first experiment Gaines presented was
for 214 hours at 100°C - there was no reaction, though the magnesium/calcium
ration of 5 was that of sea water, and the 2 molar concentration was 5 times
the salinity of sea water. Seeding the solution with a minor amount of dolomite
transformed the results dramatically.
The addition of lithium increased the
reaction as well. Apparently, the small, highly-charged Li ion strips water
from magnesium ions and frees them to become dolomite.
The next experiments dealt with varying the
magnesium/calcium ratio: ratios of 3 and 7 both resulted in less reaction, so 5
is apparently an optimum amount, probably reflecting the activity coefficient
and affecting the growth rate of crystals.
The third series of experiments dealt with
the effects of salinity, the total Mg:Ca ratio, ionic strength. In one, only 1
molar solution of Ca/Mg was used, and a slower reaction resulted. In another,
the same starting solution was used, but with salinity increased by adding
NaCl; and the result was all but identical with that using the 2 molar ionic
concentration to start with.
The final set of experiments involved
addition of organic material. A small amount of aspartic acid, noted as the
predominant amino acid in animal protein, severely retarded the reaction.
Substituting undifferentiated protein in the form of Knox's unflavored gelatin
brought the same result. Adding natural oolite ground to the same fineness also
inhibited the reaction, but the reaction was more extensive when hypochlorite
was added, its oxidizing action apparently cleaning out the organic material.
The speaker concluded that while his
experiments are not conducted under conditions identical to those in nature,
his work does indicate natural processes, notably the catalytic influence of
certain ions, such as lithium, and the dampening of reactions by organic
matter.
In response to questions, the speaker
regretfully admitted that as his reaction products are all smaller than a
micron in size, he is not yet sure that they are indeed ordered or what their
exact composition is, but x-ray results seem promising, and he proposes to use
TEM for such information.
Questions by P. Foose, Hewitt, and Zen.
The meeting was adjourned at 10:17 p.m. The
60 people in attendance made a mockery of the appeal for more beer money,
leaving a paltry $16.
Respectfully submitted,
Cristina C. Silber
Geological Society of
March 26, 1980
The meeting to order was called
from a boisterous beer-belting ball
by President Prinz
at eight hours and six.
The minutes were let pass by all.
...No, by all but one...
A much-esteemed member named Tom
at the length of my notes took alarm --
if each meeting they grate,
you can always come late --
a compromise causing no harm.
But wait! I don't want to offend
any members who meetings attend.
Tom, unsubtle hints
my sympathy win,
o my hour-long minutes I'll end.
The 1065th meeting of the Society was
called to order - poetic license notwithstanding - at 8:05 p.m. in the John
Wesley Powell auditorium. The minutes were accepted, with a desperate comment
by Tom Dutro on their -timeliness? Now new members were announced. Three
visitors were introduced:
Dr. John Pilley of
Larry yle [sic] of
Peter Feldhauser of NUS Corporation by Dan
Stanley
The return of Joe Boyd to active attendance
and the publication of "The Caledonides in the
E-an Zen gave an informal communication describing
the seismic line run by Cocorp from the
Question by Vidale.
Ian MacIntyre immersed the audience in the
cryptic habitat of a submarine
Questions by Tracey, Yochelson, Estep, G.
Helz, Zen, Sellers, Stifel, Repetski, and four unidentified individuals who can
claim their places in the minutes by seeing me after the meeting.
In the second paper of the evening, Norrie
Robbins described a variety of types of organic matter, which makes up a
significant 1 to 10% of sedimentary rocks, and its role in the formation of
economic deposits, such as petroleum, phosphates, and barite. With analyses for
carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphate in spores and pollen,
leaf cuticle, dinoflagellates, zooplankton, and actinomycetes, the speaker
demonstrated the availability of the required elements and described pathways
from compaction and diagenes to concentration and deposition. Citing examples
of known deposits of petroleum, phosphate, and barite, she urged similar
studies for the lead-zinc deposits of
Questions by G.Helz, Vidale (2), and Estep.
The "giant" mudflows in the
western Hellenic trench, as described by Dan Stanley, are of interest because
the "trench" is actually several small catchment basins close to the
Source of sediment and because the Mudflow sediments are rapidly deposited,
forming thick, uniform beds. This situation, as demonstrated in a series of 26
piston cores from three basins, is significantly different from that offshore
from the
A single question was asked.
Attendance was 94; beer money a welcome,
heartening $30.25. The meeting was adjourned at 10:10 p.m.
Respectfully submitted,
Cristina C. Silber, Secretary
THE GEOLOGICAL SOCIETY OF
April 9, 1980
The 1066th meeting of the Society was
called to order in the Powell Auditorium at 8:04 p.m. by Vice President Douglas
Rankin. The minutes were approved as corrected. The election of four new
members was announced:
Peter Guth of the
Susan Brawley of the Smithsonian
Institution
Thomas Farmer of JRB Associates, Inc.
Peter Feldhausen of the NUS Corporation
Seven visitors were introduced:
Joe Donoghue from the
Howard Gule (pronounced ghoul) from
Gene Shoemaker
Larry Bonham
Bob Andrews from the Office of Naval
Research
Bill Lloyd of the
Wayne Sigleo of the USGS, Reston
The first of two exhausting -- I mean,
exhaustive -- informal communications was a forced tour -- or rather,
tour-de-force -- by N.G. Muñoz on the disastrous disregard for geology among
developers in
The second informal communication was by
Ellis Yochelson, ever in pursuit of infinite -- or rather, definite -- detail
about Charles D. Walcott. Yochelson described his efforts to determine if
Nicholas Ratcliffe presented the first
scheduled paper of the meeting (see program for the lengthy title) Relying on
geophysical control unusually extensive for the northeastern
There is evidence of reactivation of the
ductile faults during the Mesozoic, as well as the development of the brittle
Ramapo fault. With no exposures of the latter, drilling was undertaken. Samples
from four holes, to date, consist of Precambrian rocks from the lower zone,
Mesozoic rocks from the upper, both showing parallel cataclasis. The Ramapo
fault is a soft gouge zone several centimeters wide, nether mineralized, nor
healed, and without signs of recent .movement.
Ramsay, in 1979, suggested that brittle
faults change to ductile ones with depth and predicted the depths of
epicenters, but epicenters along the Ramapo occurred below his predictions. In
response to a question, the speaker concluded his presentation with the
observation that, at the time of faulting, even ductile faults behave like brittle
ones or they would not be faults at all.
Discussion by Tom (NSF) Wright, Perry, Zen,
Lee, and Robertson.
The second paper, by John T. Hack,
considered the "Origin of the Blue Ridge Escarpment." The Blue Ridge
represents one of the few places in the Appalachians where a drainage divide
migrates, as postulated by
Stream profiles of the New River, with a
gradual slope to the northwest, and the Yadkin, with a steeper slope to the
southeast, reflect the nature of the rocks -- more resistant along the New
River -- and define the
The escarpment is breached in two areas,
each about 50 km square, lying west of the line of the escarpment while their
drainage is to the east. One, the Dan River drainage, is a case of stream
capture; the other, the
The rivers also give evidence of
differential uplift of the Blue Ridge relative to the
Questions by Reinhardt, Lee, Rankin,
Justice (2), and D. Krohn.
The final paper, on "Diagenesis of organic
matter: P-T effects," was given by Blaine Cecil. Earlier workers have not
agreed on what forces bring about metamorphism of organic matter in sedimentary
rocks -- pressure and carbon ratio according to C.D. White in 1915; temperature
and time and/or thrust pressure according to Teichmuller and colleagues in the
1960's; and, recently, according to several people, pressure. Epstein et al.,
in recent comprehensive studies of color changes related to metamorphism of
organic matter in conodonts, found that the color deepens, an indication of
greater metamorphism, with increased physical pressure and lessens with
increased water pressure.
The speaker supported pressure variations
as critical in explaining anomalies. Zones of tectonic thickening are zones of
low pressure, so there is loss of volatiles and increase in rank in organic
sediments. Using as a case history the relations of the
Another case history was cited in the
relations of calcified peat "coal balls" occurring in bituminous
coal. It seems unlikely that the balls, which are entirely enclosed by coal,
could have a thermal history different from that of the coal. Therefore,
another force must have been operating, such as pressure.
Furthermore, vitrinite reflectance in oil
and other characteristics must be consistent with thermodynamic principles.
Free-energy equations point to an important role for pressure. Increasing
temperature seems to retard reactions, in contrast.
The experiments Cecil undertook were to
simulate natural conditions, and were done under two sets of conditions:
1. under lithostatic pressure with
volatiles allowed to escape
2. under lithostatic pressure with
volatiles trapped -- therefore hydrostatic pressure approached lithostatic.
The apparatus consisted of stainless steel
pipe with a piston and O-rings for generating pressure. The whole rig could be
put in an oven to simulate geothermal gradients. The starting material was
peat, with up to 83% water, from the Okefenokee Swamp in
Results, established on a dry,
mineral-matter-free basis, are as follows:
1. in the open set-up, with volatiles able
to escape, carbon increased significantly, hydrogen decreased slightly, oxygen
decreased, and nitrogen decreased somewhat;
2. in the closed system, carbon was up but
less than in the open system; hydrogen was up slightly, oxygen down, and
nitrogen decreased, but not as much as in the open system.
Gas analyses from both types of experiments
showed three times as much CO2 and methane and less nitrogen in the
open system than the closed. Of hydrocarbon gases, the open system yielded
three times as much methane, five times as much ethylene; more ethane, more
propylene, and less propane as the closed system.
Thin sections of the residual peats after
treatment in the open system showed a dramatic color change and textural
banding; this suggests that banding is not necessarily a primary feature. The
experiments were run with the assumption that the volume was unchanged; in
fact, allowance must be made for a ten-fold compaction. In conclusion, the
speaker declared that such experiments show that thermal history is just part
of the story: Pressure also affects hydrocarbon maturation.
Questions and discussion by Piaget, G.
Helz, Simon (2), Sato, Robertson, Zen, Repetski, and Epstein.
Attendance was 108. The meeting was
adjourned at 10:27 p.m. Money for refreshments was $29.10.
Respectfully submitted,
Cristina C. Silber, Secretary
GEOLOGICAL SOCIETY OF
April 23, 1980
The 1067th meeting of the Society was
called to order by President Prinz in the Powell Auditorium at 8:03 p.m. The
minutes were read and approved, after a discussion of starting times recorded
and a re-setting of watches. There were no new members; the following visitors
were introduced:
Ina Alterman of the NRC
Eiliv Steinnes,
Bob Jahns, an engineer from
A1 Burch
Steve Broun
The president announced the death, in April
of 1979, of member C.C. Nikiforoff.
In response to Dutro's timely remarks about
the minutes and our starting time, Bruce Hanshaw communicated his sense that a
paleontologist should not be allowed to quibble about 8 minutes. A gratified
gleam in his eye, Dutro observed that he is no longer a paleontologist, but a
minion of the Office of Surface Mining.
Dutro then announced that on behalf of
Ellis Yochelson, he would show the slides not projected for Ellis' informal
communication at the last meeting because of a burned-out projector bulb. The
slides were offered strictly as given to him, and Dutro refused to entertain
any questions. From said slides, the audience learned that (1) C.D. Walcott did
heretofore unreported field mapping by horseback in the
Moving on from informal informal
communication to formal informal communication, Bob Tilling discussed recent
activity at
Ash, blown by prevailing winds from the
west, has risen up to 25,000 feet above sea level and, at its most extensive,
formed a curtain 25 miles long. Starting on April 1, there were harmonic
tremors for 5 days, and another on April 12, denoting the movement of magma,
but none has emerged, and all the material ejected to date is reworked.
After the second crater formed, blue flames
could sometimes be observed flickering between the two, and the smell of H2S
was reported. As there is no evidence of high temperature, it has been assumed
that the gas is not hydrogen. The gases have recently been sampled, but results
are not yet in.
Possible hazards have been evaluated by the
Forest Service and the Burlington National Railroad, which own or manage most of
the surrounding area, and emergency measures planned.
Questions by Masursky, Tracey, Zen,
Toulmin, Robertson, Sato, Simon, and B. Hanshaw.
The first paper was by T.O. Wright on
"Graptolites as strain gauges in the Martinsburg formation of
Wright studied ten good localities,
representing the full range of bedding and cleavage relations. Measurements of
width, space between thecae, angle between the long axis of the grap and the
trace of cleavage on bedding surface demonstrated that the graps have sustained
shortening and therefore loss of volume.
The shortening represents a 50% loss of
material and persists throughout the 2000 feet of section studied over 80 km
along strike. Wright rejected constant-volume processes to explain the
shortening. The appearance of calcite veins in the shale is such as to rule out
dewatering as the mechanism of loss of volume, and the distribution of veins is
inadequate to accommodate the lost material. Furthermore, pelmatozoan corals,
in response to cleavage-generating pressure, show material loss parallel to
cleavage without precipitation of calcite in the pressure shadows. The
concentration of opaque minerals between the corals suggests loss of silicates,
as well. Some organic matter persists in the shale; though some may have been
destroyed, it would not be enough to account for 50% of the original volume.
Questions by Repetski, Alterman, Robertson,
Cecil (2),
L. A. Hardie and his associates analyzed
present-day environments of deposition to explain features and sources of
Cambro-Ordovician carbonate deposits, as elucidated in the second talk,
"Ancient and modern carbonate sediments: A comparison in form and
process."
The study was conducted at three scales:
kilometer, to evaluate the shape of the deposits; tens to hundreds of meters,
to distinguish different facies; and meters, to define the components of each
facies. Deposits seem to occur in three recognizable shapes: The attached
shelf, as at
The Permian Capitan reef, carbonate
platform, and associated basinal sediments represent one well-described ancient
environmental complex. The 8-to-10,000 feet of Cambro-Ordovician sediments in
the Frederick-Conestoga valleys comprise a basinal ramp or shelf.
On the facies scale, three depositional
environments can be distinguished: The platform with patch reefs in a lagoon;
the slope, where fine sediments are supplemented by storm-dislodged blocks; and
the basin, where finest sediments are interbedded with hemipelagic and pelagic
sediments or disturbed by turbidity flows.
Hardie's slides of the St. Paul Group of
Ordovician age in the Great Valley illustrated a sequence of environments from
an algal marsh (receiving sediment only during hurricanes and characterized by
superb. development of lateral-linked stromatolites), to a tidal flat to an
open lagoon to a restricted lagoon. Existence of the same features on
Now undertaking a comparable study of the
Cambrian Conococheague formation, Hardie has found the same facies, but in
different organization, so a different regime awaits deciphering.
Questions by T. O. Wright, Guth, Newman, B.
Hanshaw, Estep, Jones, George Stanley, and Cecil.
In the final paper, Harold Masursky
described "The exploration of Venus by radar: The Pioneer Venus
Mission." Before the mission, 25% of Venus had been mapped from Earth by
interpreting a flow of radar data likened to drinking from a fire hydrant. 'The
Pioneer Venus Mission has mapped 80% to date --the rest due by May-- making one
traverse a day, getting one data point every 120 km; filling in on subsequent
passes, and, ultimately, giving a resolution of 30-100 km. This is like
drinking beer through a thin straw, Masursky observed dryly --"You can get
high, but it takes a long time."
Interpretation of craters, ridges, volcanic
vents, rifts, and other features have been corroborated by a number of landings
of unmanned Soviet spacecraft, which also confirmed identification of basalt by
gamma ray spectrometry.
2% of Venus is lower than mean level; 10%
consists of true highlands; and the rest is rolling terrain between, with a
total relief of 15 km. This is in contrast to bimodal distribution of mean
elevation on Earth into deeps and highs totaling 20 km of relief. The crust of
Venus is fractured complexly like that of Earth and Mars. Most of Venus is
covered by ancient crust with no mid-ocean ridges on our terrestrial scale.
Neither are there marginal troughs to the land masses, leading to the
conclusion that global plate tectonics are not operating there. Geophysical
data suggest that the crust is mobile like Earth's, however.
Two more Russian spacecraft, in whose
experiments we may have some choice, are scheduled for the near future. In
1986, the
In conclusion, Masursky pointed out that
Earth is even more remarkable than we thought --to date, the only body with a
biosphere and the only one with plate tectonics.
Questions by Stewart (2) and Towe.
Attendance was 96; refreshments raised
$33.26; the meeting was adjourned at 9:58:43.
Respectfully submitted,
Cristina C. Silber
GEOLOGICAL SOCIETY OF
May 14, 1980
The 1068th meeting of the Society was
called to order by President Prinz at 8:08 p.m. The minutes were approved as
read. Fifteen new members were elected, and six visitors introduced.
The first of two informal communications
was by David R. McQueen, proposing to characterize classes of ore deposits on a
ternary diagram and thereby to clarify our thinking and render vocabulary
consistent. At each apex, McQueen set one group of processes of ore
concentration, namely aqueous, magmatic, and metamorphic, including mechanical.
On such a diagram, evaporites would lie at the aqueous apex; skarn deposits
between aqueous and metamorphic; and komatiites between the magmatic and
metamorphic points. For the special problem of placers, a quarternary diagram
could be constructed with an apex for mechanical processes separate from
metamorphic one . As in composition diagrams for minerals, the relative
contribution of the processes could be expressed as proportions. Questions by
Fletcher and Estep.
The second informal communication was by
Eugene C. Robertson about lab work on friction between slabs of rock and
measurements, in mines and out, of gouge related to extent of displacement
along faults. Except in the case of low-angle overthrusts, Gene finds that
displacement is 100 times the thickness of gouge, independent of rock type. For
near-surface faults under less confining pressure, there is less gouge relative
to displacement. Questions by Rankin, Lipin, Zen, and Guild.
Steven Lonker of the Geophysical Laboratory
presented the first talk of the evening, on "Late Proterozoic uplift and
cooling history, southeastern
Textural disequilibrium in the rocks was
manifested in the juxtaposition of indented crystals. Chemical disequilibrium
could be seen, on the one hand, in zoning such as iron enrichment in garnets near
contact with biotite and magnesium enrichment in cordierite near garnet and, on
the other, in the way compositions plotted up on various diagrams.
Garnets have corona textures of cordierite
around them, and embayment-ended biotite occurs. The origin of the corona
texture is definitely related to pressure, but not necessarily to temperature:
The lower the pressure, the larger the corona. On the other hand, there is
consistent change in compositional assemblages with increasing temperature such
that the assemblages can be mapped as isograds.
Such petrologic information defined the
nature and history of cooling in the area. Study of geologic structures
revealed that uplift was roughly equaled by erosion.
Questions by Robertson and Zen.
The second paper was by Mitchell Reynolds,
US GS, on the "Influence of continental intraplate shear on development of
thrust faults,
Extensive mapping in the overthrust belt
has revealed significant differences from one segment to another. In general,
the trend of the belt is northerly, with older rocks from the west thrust over
younger ones to the east, and plutons associated with the western portion. In
north-central
Evidence for an intracontinental shear zone
5-to-30 km wide along the so-called Lewis-and-Clark line in Montana is
extensive, with heat flow different on each side; basin-and-range terrain to
the south, but none to the north; a strong gravity gradient to the south, but
not the north; and aeromagnetic differences. While the line per se has only
existed for 17 million years, differences, such as the emplacement of
Precambrian basic sills north of the present line, define a long-active zone.
In the pre-middle Cambrian, the zone of the present line was the hinge between
anticline to the north and syncline to the south; in the pre-Jurassic, pinnacle
reefs formed north of the line, but not south of it; and in the Tertiary, the
rocks and structures are different on each side.
These differences result from varying water
content in the rocks and from the thermal history. The latter has produced late
post-mature to metamorphic rocks, which means that any oil once present has
been destroyed and any gas driven off.
Questions by Eaton, Robertson, Zen, Clarke,
and D. Krohn.
The final paper, "Mineral textures as
indicators of reaction mechanisms and mineral solubilities," was the work
of Richard Sanford, US GS. Using a petrographic microscope to examine
relatively simple rocks, the speaker evaluated the nature and direction of
displacement of mineral contacts from which he derived data on the relative
mobilities, concentrations of species, and mechanisms of reaction.
The speaker discussed a serpentine quarry
overlain by greenschist of ultramafic chlorite and actinolite with a zone of
talc between the lithologies. The reaction to be evaluated involves serpentine
+ 2 quartz = talc + H2O. Using the principles that the mineral
contact is displaced in the direction opposite to the more mobile component and
that the volume is much less for the side from which the more mobile component
moves, Sanford determined that most of the talc came from serpentine, so SiO2
is a more mobile flux in this case than MgO.
The mobility of a flux is a product of the
concentration times the velocity, or diffusion rate. As velocities are quite
constant, the relative velocities of the fluxes under consideration are
crucial. This approach can be widely applied in studying the kinetics of rocks.
His findings match experimental data on the same systems.
Questions by D. Krohn, D. Milton, G. Helz,
and Stewart.
The meeting was adjourned at 10:16.
Attendance was 84.
Respectfully submitted,
Cristina C. Silber, Secretary
GEOLOGICAL SOCIETY OF
September 24, 1980
The 1069th meeting of the Society was
called to order by Vice President Rankin at 8:05 p.m. in the Powell auditorium.
The minutes were approved as read. Three visitors were introduced. The Cosmos
Club handed out printed notices that jackets and ties should be worn by GSW
members, especially on trips through the dining room, and various strategies
for non-violent protest were considered. The suggestion was made that all members
present ourselves for the several jackets and ties the Club supplies for the
convenience of the rare, ill-informed visitor, but Club members protested that
their dues would be raised to cover the new burden of overhead. After several
more irreverent, not to say provocative, suggestions, the consensus was
achieved in favor of studied indifference.
Francis J. Flanagan of the USGS presented
an informal communication on analytical results for some samples of carbonatite
from
In the first formal talk, "Subduction
processes in South America", Selwyn Sacks of the Department of Terrestrial
Magnetism described unexpected contortions of the Nazca plate which moves from
the East Pacific Rise toward the west coast of
To better elucidate the situation, seismic
data were collected and plotted at 25-km-wide intervals from southern to
central
There are too few seismographs for good
control further to the north, so investigators resorted to analysis of focal
mechanism, shear waves, and anelasticity. Measurement of focal mechanism
demonstrates that the dip goes from 30° to 10° below 100 km and then back to
30° at some distance inland. Analysis of shear waves versus compressional waves
gives a 30° dip for the top 100 km of subduction. The pattern of arrivals of
high frequency waves at different stations reveals a "shadow" zone
where, actually, no high frequency waves arrive, leading, to the supposition
that such waves are being bounced off the base of the subducted zone at the
gentle part of the curve.
Sack's interpretation of the data is that
the Nazca plate is subducted like other plates at first, but flattens out at
about 100 km depth because the lithosphere is less dense than the
aesthenosphere and becomes denser along its lower surface by plating from the
aesthenosphere. The upper surface, being less dense, bends as the lower surface
drags in contact with the aesthenosphere. Once horizontal, the plate moves
along until it collides with the Brazilian shield, at which point the plate
dives downward again.
The speaker compared several aspects of the
processes in South America with those in the East Philippine Sea and
Three questions by Dickey; others from
Robertson, Rankin, G. Helz, Zen, Leo, Tracey, and Sato.
The second talk was by Donald Grybeck,
USGS, on the "Mineralogy and ore deposits,
Question by Dickey and two by Gizé.
Attendance was 78; adjournment was at 9:33;
collection for refreshments was $29.00.
Respectfully submitted,
Cristina C. Silber, Secretary
THE GEOLOGICAL SOCIETY OF
October 8, 1980
The 1070th meeting of the Society was
called to order by President Prinz at 8:05 p.m. The minutes were approved as
read. Twenty-three new members were introduced and two visitors, Jim Silliman
and Lu-Han Fu, were welcomed. The membership paid silent tribute to the memory
of William Fisher, Robert Hackman, and Joseph Fahey, who died recently.
Announcements were made of upcoming talks,
including two co-sponsored by the AAPG. Mike Foose asked that members who are
not getting their meeting notices should let him know, as he is tackling the
printer to improve delivery.
There being no informal communications, we
moved to the formal presentation Mackenzie Gordon made a strong case for
"Biostratigraphy -- the field geologist's friend" by demonstrating
the crucial role of biostratigraphy involving four geological problems:
Correlation of rocks in a flysch basin in Oklahoma and Arkansas; resolving the
dilemma of the Pennsylvanian-Mississippian boundary in part of Wyoming by
defining the age of the Amsden formation and correctly identifying and
interpreting its deposition as an eastward transgression with no deformation;
unscrambling part of the complex of faults and unconformities in the Great
Basin of Nevada and Utah; and pinpointing of the Bergin Ag-Pb-Zn deposit in the
east Tintic Mountains in Utah by identifying a relatively little-known
Mississippian colonial coral, interpreting the structure of the rocks as an
overturned syncline with a major fault separating the Cambrian from later
Paleozoic, and defining the area to be explored by drilling.
Reeling after the comprehensive
presentation, the audience was completely softened up by Gordon's diplomatic
conclusion that many disciplines were involved in solving such complex problems
and that biostratigraphy will be useful in many more to come. There were no
questions.
T. O. Wright of NSF gave the second talk,
on "Ganovex-79, the West German North Victoria Land expedition." In
the course of gaining experience and establishing a permanent station in
Antarctica, a West German team plus the speaker worked in North Victoria Land
to unravel the relations of rocks there to those in eastern Australia and/or
Tasmania, undertaking the equivalent of landing in D.C. and mapping from New
York to South Carolina -- in one field season:
Wright concentrated on the
The correlation to the
Questions by Sohn and Prinz.
The final paper was by George Fisher of
Johns Hopkins on "Isograd migration in response to heat transfer during
Acadian folding, eastern
Petrographic study revealed three textural
types: Rocks with staurolite and kyanite from both S2 and S3
deformations; rocks with garnet-zone rocks from S2 and
staurolite-kyanite from S3; and rocks with staurolite-kyanite from S2,
retrograded during S3. These three occur in separate regions define
by isograds.
Fisher illustrated the impact of folding on
the isograds: With continuing heat flow, small folds on a scale of 1 km in the
isograds will be obliterated while folds on the order of 10 km will be reduced,
but still preserved. He calculated that the rate of isograd movement during the
Acadian orogeny was 2-200 cm/year and that their location can be resolved to
within 100 m.
One question each from Rumble and
Robertson; 2 each from Stewart and Sanford.
The meeting was adjourned at 9:34 with 86
present.
Respectfully submitted,
Cristina C. Silber, Secretary
THE GEOLOGICAL SOCIETY OF
October 22, 1980
The 1071st meeting of the Society was
called to order by President Prinz at 8:02 p.m. in the Powell auditorium. The
minutes were approved as read after a point of clarification by Dutro that
minutes should review what a speaker said, not necessarily The Truth, and that
members of the audience should address themselves to speakers, not to the a
secretary, when wishing to correct faulty interpretations.
Seven visitors were introduced; two
announcements were made about complying with the Cosmos Club dress code and
paying for parking in the Club lot; upcoming lectures by two AAPG speakers were
announced again.
The first talk was presented by David
Elliott of Johns Hopkins on "The Moine Thrust". With colleagues Boyer
and Johnson, the speaker made a geometrical analysis of the thrust complex over
its 800-mile length from the Shetland Islands to
Scolithus in a bed of so-called "pipe
rock" were used as strain gauges and showed little deformation, an
indication of thrusting. Displacement was determined to be about 75 km. In the
central part of the area, the thrust sheets are exposed and show imbricate
structures like those produced experimentally by Connell in a sandbox.
The central area differs from the more
northern and southern ones in having numerous igneous intrusions which are more
rigid and result in more faulting. The intrusions predate the folding and
bracket it.
The speaker described the fault system in
terms of "duplex thrusts", following a "staircase
trajectory" and resulting in some cases in decapitated folds. He went on
to compare the Moine with the Lewis thrust in
Questions by Towe, Robertson, Rankin, and
an unknown.
The second paper was by Robert West of the
Despite this constraint, with his
associates, West was able to collect remains of a considerable variety of
animals with some representatives in
Europe, others in
Questions by Whitmore, Towe, Tracey, and
Zen.
The third talk, by Robert Tilling,
consisted of an "Update on
Single questions by TO Wright, Robertson,
Leo, Zen, Boyd, Towe, and doubles by Hicker, Toulmin, and Prinz.
Adjournment was at 9:48; attendance, 114.
Contributions for refreshments reached $30.33 and $4.70 was collected from the
sale of guidebooks.
Respectfully submitted,
Cristina C. Silber, secretary
GEOLOGICAL SOCIETY OF
November 12, 1980
The 1072nd meeting was called to order by
President Prinz at 8:03 p.m. in the Powell Auditorium. The minutes of the
previous meeting were approved as read. Four new members were Elected by the
Council:
Larry Drew - USGS, John Sutter - USGS, H. Tren Hasleton - USGS, Tom Lierman - Geo.
Wash. University
Three guests were introduced. President
Prinz then presented the slate of proposed officers for 1981, as required by
the by-laws, and further nominations were invited. Prinz also announced a
proposed change in the by-laws to permit an increase in dues to $8.00 for full
members and $2.50 for retired members. Corresponding members' dues would remain
unchanged.
Anita Harris presented the first paper of
the evening on "The Little Conodont that Could." In a comprehensive,
cartoon-illustrated talk, Harris rehabilitated the conodont from enigmatic
obscurity to indispensability. Conodonts are widely distributed in a variety
of depositional environments; are resistant and identifiable even in
structurally deformed rocks; have persisted through time with rapid change of
morpho-types; serve as an index of metamorphism by changing color from pale
yellow to black through carbon fixation; permit the definition of color
alteration isograds which can be correlated with production of oil and gas;
exhibit fluorescence related to color alteration in both UV and blue light;
serve as chronometers; and persist in metamorphic rocks up to garnet grade.
Harris rounded out her talk with the techniques of separation and
identification.
Questions by Menard, D. Milton, G. Helz,
Sato, Zen, Sanford, and Robertson.
The second paper was by D.J. Milton on the
"Geological problems of impact craters." Citing simple, complex, and
ringed craters as the structural types,
Questions by A. Harris, Menard, and Sato.
W.R. Keefer presented the final paper,
"Tectonic significance of basins in the
Question by Repetski and Zen.
Attendance was 84, and adjournment at 9:48
p.m.
Respectfully submitted,
Cristina C. Silber, Secretary
GEOLOGICAL SOCIETY OF
December 12, 1980
The 1073rd meeting of the Society was
called to order by Vice President Doug Rankin at 8:05 p.m. in the John Wesley
Powell auditorium. The minutes of the preceding meeting were approved as read.
No new members had been elected. Visitors included Barbara Prinz, Mary Rankin,
Phil Hunter of the USGS, and Dr. Andre Ilyin from the
Carl Thornber announced a GSW field trip to
the new living coral reef established at the
Other announcements were that Bob Tilling
would address the Potomac Geophysical Society about
Bill Prinz then presented his presidential
address on the geology of the Arabian shield, which was separated from the
Nubian shield of
The cornerstone of the USGS program in
As Bill finished up his deductions on
subduction at 9:05 p.m., the 94 people in attendance broke for refreshments, as
much to recover from sun-drenched scenery as to prepare for the ensuing annual
meeting.
Respectfully submitted,
Cristina C. Silber, secretary
88th Annual Meeting
Geological Society of
December 12, 1980
The 88th Annual Meeting of the Society was
called to order by President Prinz at 9:20 p.m. The minutes of the 87th
meeting, December 12, 1979, were read by former Meetings Secretary John Keith,
corrected by R. Helz, and approved. The report of the Council Secretary, John
Keith, was accepted. The report of the Meetings Secretary, Tina Silber, was
also accepted.
Not so easy for the Treasurer. He cited a
total income for the year of $5000, of which $3963 was from dues, the balance
from interest, sale of historic guidebooks, and other incidentals. This
represents a gain of $400 over last year. The Bradley Prize for best paper of
the year will be worth $180 this year.
The auditor, Peter Lyttle, expressed
approval of Mike's management of Society funds this year. Frank Whitmore moved
that the Treasurer's report be approved; the motion was seconded and passed.
The brouhaha arose in a discussion of
proposed dues increases: To $8 from $7 for active members and $2.50 from $2 for
retired members, corresponding members' to be held stable. Dutro made an
impassioned plea that dues be held the same in these times of rampant
inflation, at least for retirees. Lipin observed that Retirees are making more
money than full-time workers. To an anonymous voice asking how many retirees
belong to the Society came Hatch's trenchant reply, "More every day,"
a statement corroborated from the official records showing a staggering
increase of 17 since last year, for a total of 142 .
The Voices of Experience, ex-Treasurer M.
Appleman, and Sage, Phil Guild, added words of wisdom in favor of the status
quo, prompting the Treasurer to discuss a possible computerized mailing system
that could be instituted at the USGS as a means of keeping costs down somewhat.
To Mary Hill French's mild inquiry as to whether the new system would save
money, Foose, feeling the pressure, replied "Money is not the
problem!"
A diversion about applying income from the
Bradley Fund to meet costs of having speakers was cut off by Kinney moving the
previous question. Alas, there was none on the floor. In due course, one
materialized, was seconded, and the proposed dues increase fell to a vote of 26
aye, 41 nay.
Calm was restored by Mary Mrose presenting
the annual drama of the membership: The total of 1,017 was up 45 from last
year, including addition of 52 new members, loss of 4, resignation of 6, and
dropping of 42 for non-payment of dues after 2 years. The totals are 642
active, 233 corresponding, and 112 retired members. Mary extolled the efficacy
of second notices for unpaid dues, noting that 77 did not pay their dues in
1979 and 33 had to be dropped, while this year, with no second notices sent,
158 did not pay and 70 were up to be dropped. Assured that second notices were
in the works again to rectify this deplorable state of affairs, the membership
moved, seconded, and accepted Mary's report.
Doug Rumble emerged as the chairman of the
Committee for the Great Dane and Bradley awards. Before turning to his
announcements, he enlisted the audience in a rousing expression of appreciation
for Program Chairman, Pete Toulmin. He then ran through all the informal
communications and singled out Bob Tilling's timely and interesting report on
For both content and presentation, Rumble's
committee chose Robert West's paper on "Fossil Vertebrates and the
Cenozoic History of the
The new low hit by the Society in the past
year was identified and past exploits lamented by P. Hanshaw, whose anonymous
committee chose not to award the Sleeping Bear Award this year. Too little
spontaneous humor, the committee opined; it is hoped that the shock of the
award being withheld will provoke a revival of humorous enterprise in the
Society in the coming year.
The meeting was duly adjourned, and
participants repaired to the beer keg for inspiration in reviving humorous
enterprise and other pleasant pursuits.
Respectfully submitted,
Cristina C. Silber