GSW: 2008 MEETING MINUTES
Geological Society of Washington
Geological Society of Washington
Minutes from the 1417th Meeting,
Wednesday, January 24, 2008
John Wesley Powell Auditorium,
Cosmos Club, Washington, D.C.
At
8:00 PM President Craig Schiffries promptly and cleanly called to order the 70
attendees.
Jeff
Grossman of the USGS, possibly confused as to the current year, read the
minutes from the 783rd meeting to much laughter and exultation, then reminded
the audience that minutes from historical GSW meetings can be found on the
Society’s website.
The
minutes of the 1416th meeting were read with significant patience from the
audience. The minutes were accepted although John Slack provided some
post hoc corrections.
To
the pleasure of the audience and to the chagrin to the secretary’s note-taking
hand, a deluge of guests were introduced: Dave Mittlefehldt (Johnson
Space Center), Jason Murray (NOVA CC), Michelle Arsenault (NSF), Joseph Colgan
(USGS), Jessica Wall (AGI), Rachel Shannon (SS Papadopolous & Associates),
and Ashley Nichols (NOVA CC).
The
election of two new members was announced: Manik Talwani of the International
Ocean Drilling Program – Management International and Lisa Schleicher of the
University of Maryland. Shockingly, both members were present and stood
without hesitation when their names were called.
President
Schiffries then asked the audience to hold a moment of silence for the recent
passing of Marty Toulmin. This was followed by a call for GSW members to
volunteer for local area science fairs. Lastly, Callan Bentley announced that
NOVA CC is holding a Climate Change Symposium on February 1st.
The
first formal talk of the evening was given by Derek Schutt of the National
Science Foundation who discussed the Yellowstone hotspot and “how it got that
way.” The presentation initially focused on the shaky and traumatizing
childhood of this oft misunderstood geologic feature. Using evidence of
Rayleigh wave velocity variation with depth and estimates of excess temperature,
Derek suggested that the Yellowstone hotspot is a “bottom-driven” detached
plume rather than a “top-driven” adiabatic upwelling. He went on to
speculate that the hotspot may have formed as a result of the subducting
Farallon slab. Questions were asked by Sash Hier-Majumder (U of
Maryland), Jamie Allen (NSF), and Bill Leeman (NSF).
The
second formal talk of the evening was given by Eloise Gaillou of the
Smithsonian Natural History Museum who discussed the causes of color in gem
opals. In this visually spectacular presentation, Eloise demonstrated
that the various colors in opals were a result of inclusions of minerals and/or
were associated with relatively high concentrations of various elements and
organic constituents. She also went on to discuss that the play-in-color
of opals results from light diffraction in samples exhibiting an ordered
nanostructure of well-sorted spheres. Questions were asked one each by
Jamie Allan (NSF), Linda Rowan (AGI), George Helz (U of Maryland), Liz Cottrell
(Smithsonian), and Rick Wunderman, (Smithsonian) and 2 each by Dan Milton and
Mac Ross (both USGS – retired).
The
final talk of the evening, “Isotopic evidence for natural and synthetic
perchlorate in groundwater,” was given by J.K. Bohlke of the USGS. J.K.
presented data demonstrating that natural sources of perchlorate, such as
fertilizer from the Atacama desert, are 37Cl depleted and 18O enriched relative
to synthetic sources, and contain a large excess of 17O. Using data from
field sites of on-going research, he was then able to show that these isotopic
differences allow for determination of sources and processes involving
perchlorate in groundwater systems. Questions were asked one each by Rich
Walker (University of Maryland) and Doug Rumble (Geophysical Lab) and 2 by
George Helz (University of Maryland)
After
the cessation of the talks, special recognition was given to Linda Rowan of AGI
for her hard work as GSW program chair. The audience was reminded that
Tim Mock of the Carnegie Institution is the new program chair and his
information can be found on the GSW website.
President
Schiffries announced the upcoming slate of speakers and their talk titles, and
called the meeting to close at 9:30 PM.
Respectfully
submitted,
Mark
A. Engle
Geological Society of Washington
Minutes from the 1418th Meeting,
Wednesday, February 13th, 2008
John Wesley Powell Auditorium,
Cosmos Club, Washington, D.C.
At
8:02 PM President Craig Schiffries called to order the unruly 43 attendees who
continued to produce a noticeable ruckus well into the reading of the minutes
of the 1417th meeting. Three corrections to the minutes were offered and
noted.
The
following guests were announced: Dominic Papineau (Geophysical Lab), Paul
Craddock (WHOI), Jodi Gaeman (U of Maryland), Elena Chung (U of Maryland),
Eugenia Leone (U of Maryland), Garrett Mitchell (U of Maryland), Carolyn
Gramling (AGI – Geotimes), James Day (U of Maryland), and Jessica Warren (DTM).
President
Schiffries then asked the audience to stand and hold a moment of silence for
the recent passing of William Back (USGS-retired), a 56-year member of
GSW. Charna Meth, the GSW Public Service Committee Chair, encouraged
audience to volunteer as judges at the upcoming local area science fairs.
Jessica Ball (AGI) announced the release of a DVD entitled “Why Earth Science”
which consists of a short presentation intended to highlight the importance of
earth science in K12 education. President Schiffries then announced the
1st ever Bradley lecture on April 9th, 2008, which will be given by Sean
Solomon, Director of the Carnegie Institution of Washington's Department of
Terrestrial Magnetism (DTM) and Principal Investigator for the MESSENGER
mission to Mercury. The topic of the lecture will be MESSENGER's recent
flyby of Mercury and what their observations are revealing about the geology of
the innermost planet.
This
was followed by a observation that the meeting minutes had not been
approved. The minutes were immediately approved with liberal and excited
use of the gavel by President Schiffries.
No
informal communications were given.
As
usual, three formal talks were presented at the meeting. The speakers
apparently took it amongst themselves to perform an act of rebellion by
exceeding the 20-minute presentation time, in one case by nearly 3
minutes. As punishment, descriptions of their respective talks are
limited to 20 words or less, in the following minutes.
The
first formal talk of the evening was given by Aaron J. Martin of the University
of Maryland who compared models of a bulldozer pushing sand and of a tube of
toothpaste being squeezed as mechanisms for Himalayan tectonics.
A
single question was asked by Nick Woodward (DOE).
The
second formal talk of the evening, “ Recovery of the ozone layer,” was given by
Darryn Waugh of Johns Hopkins University. Darryn presented data showing
that stratospheric ozone concentrations are just starting to recover as a
result of the Montreal Protocol.
Questions
were asked one each by Glenn Chinery (EPA), Doug Rumble (Geophysical Lab),
Naomi Lubick (ES&T), Roz Helz (USGS – retired), George Helz (U of
Maryland), Mark Engle (USGS), Craig Schiffries (GSA), and 2 by Mack Ross (USGS
– retired).
In
final talk of the evening, “bugs” was the answer to Bradley de Gregorio’s
(Naval Research Lab) talk entitled “Bugs or gunk? Novel approaches for
assessing the biogenicity of Earth’s oldest microfossils.”
Questions
were asked one each by George Helz (U of Maryland - retired), Brooks Hanson
(Science), Dominic Papineau (Geophysical Lab) and 2 by James Day (U of
Maryland)
Following
the talks, recognition was given to Tim Mock of the Carnegie Institution for
setting up the evening’s program. President Schiffries announced the
upcoming slate of speakers and their talk titles, and called the meeting to
close at 9:42 PM.
Respectfully
submitted,
Jamie
Allan for Mark A. Engle
Geological Society of Washington
Minutes from the 1419th Meeting
Wednesday, February 27, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
At
8:06 PM, President Craig Schiffries called to order 76 well-behaved attendees,
after a brief delay to ensure the projector was working. One important
correction to the minutes of the 1418th meeting was offered and noted. The
meeting minutes were then approved.
The
names of no less than 10 new members were read, an apparent record for new
membership announced at a single meeting in recent memory. Controversy
regarding this announcement erupted in two ways. First, it was clarified that
it was a record only because half of them weren’t announced at the previous
meeting. The Acting Secretary further confused matters (and also showed his
rookie status), by miscounting the number of new members as 12. In any event,
this is great news for the Society, with 22 new members this year (since October
1).
The
new members are:
Rachel
Shannon, S.S. Papadopulos & Associates
Dave
Freeman, University of Maryland, Emeritus
Michelle
Arsenault, National Science Foundation
Jessica
Ball, American Geological Institute
Laurent
Montesi, University of Maryland
Wen-lu
Zhu, University of Maryland
Stephen
Self, U.S. Nuclear Regulatory Commission and The Open University
James
Day, University of Maryland
David
Simpson, Incorporated Research Institutions for Seismology
Raymond
Willemann, Incorporated Research Institutions for Seismology
The
following guests were announced: Carol Simpson of Old Dominion University, Cat
Smith of the Australian Embassy, and Maggie Wedner, from the German Embassy. A
fourth unannounced guest was also present, Roger Smith of the University of
Alaska, Fairbanks.
Bill
Burton announced that the Geological Society of America is seeking a
co-chairman for the 2010 Southeastern Section Meeting. He then announced a
tentative field trip to Popes Creek to examine coastal erosion, with the field
trip to be led by Wayne Newell of the USGS. Please contact Bill if you are
interested in either chairing the meeting or the fieldtrip. President
Schiffries then announced, on behalf of Charna Meth, that volunteer judges were
still needed for local area science fairs. The Prince William County and
Fairfax County science fairs still need one judge each, and 2 judges are needed
for the Washington, DC and Prince George’s County science fairs. Please contact
either Charna Meth of President Schiffries if you are interested.
No
informal communications were given.
Three
excellent talks were then presented at the meeting.
The
first, entitled “Volcanoes are Geysers,” was given by John C. Eichelberger of
the U.S. Geological Survey at Reston. John started his talk by noting his
apprehension- this talk represented his “coming-out party” for moving to the
“death star” of Washington, D.C. after living his professional career on the
“fringes of civilized society” in Fairbanks, Alaska. John then proceeded to
demonstrate that volcanoes are not only like geysers, they are also like an
$8.95 Wal-Mart coffee maker. The key is to realize that magma erupting within a
conduit represents a decompressing boiling liquid, with boiling and subsequent
eruption emptying the conduit, thereby drawing up more liquid into the conduit
from the magma reservoir below. Where the magma is gas charged, less viscous,
and has good conduit connectivity to the magma reservoir, plinian eruptions may
proceed. Other conditions lead to more episodic and less explosive eruptions,
with conduit connectivity and magma viscosity important.
Questions
were asked by Bill Burton of the USGS, Brooks Hansen of Science magazine, Joe
Smoot of the USGS, Carol Simpson of Old Dominion University, Linda Rowan of
AGI, George Helz of the University of Maryland, and Rick Wunderman of the
Smithsonian Institution.
The
second talk, given by Reto Gieré of the University of Freiburg, was entitled
“Mineralogy of the Atmosphere: Assessing Environmental and Health Impacts of
Airborne Particulate Matter.” Reto proceeded to scare the wits out of the
audience by showing us what we are actually breathing in. A major problem with
societal laws governing emission of particulates is that they focus simply on
size, rather than on composition and shape. Work sampling coal fly ash
emissions from a Purdue University power plant stack show the fly ash to be a
veritable dog’s breakfast of materials, much of it toxic. Particularly
interesting and frightening is that some particulate matter, because of size and
composition, is almost impossible to remove from our lungs. A significant
portion of it is from automobile tires.
Questions
were asked by Mac Ross of the USGS (retired), Naomi Lubick of the
Environmental Science and Technology Journal, Brooks Hansen of Science
magazine, Bill Burton of the USGS, and Jamie Allan of NSF.
The
third talk, given by Jessica Warren of the Department of Terrestrial Magnetism,
Carnegie Institution of Washington, was entitled “Sampling Mantle Heterogeneity
at Ultra-Slow Spreading Ridges.” Jessica pointed out how difficult it was to
study earth’s mantle due to lack of access, noting that geochemists like to
draw simpler mantle cartoons than geodynamicists. Ultra-slow spreading centers,
defined as spreading less then 2cm/year, are great places to study oceanic
abyssal peridotites and therefore mantle processes, as the magma production
rate from spreading ridge melting is so low as to cause erupting magma to be
focused at central volcanoes, leaving much of the ridge crest floored by mantle
rock. Despite abyssal peridotites often being grotty because of low temperature
alteration, unaltered mineral cores provide isotopic and trace element
compositional data crucial for modeling mantle melting, melt-wallrock
interaction, and melt impregnation, even recording effects of passing mantle
plume interaction with depleted mantle. Studied samples from the Southwest
Indian and Gakkel Ridges indicate mantle compositional variation present at all
length scales and greater than previously inferred. This heterogeneity does not
result from simple component mixing between depleted mantle and recycled crust,
but instead represents long-term heterogeneities with small scale
heterogeneities representing recent melt-wallrock interaction.
Questions
were asked by Bill Melson, Smithsonian Institution (retired), and Rich Walker
of the University of Maryland.
President
Schiffries announced the slate of speakers and their talk titles for the
upcoming 1420th meeting, and then closed the meeting at 9:50 PM.
Respectfully
submitted,
Jamie
Allan
Geological Society of
Washington
Minutes from the 1420th Meeting
Wednesday, March 26, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
At
8:02 PM, Acting President Bill Burton called to order 50 attendees. Two minor
corrections to the minutes of the 1419th meeting were offered and noted. The
meeting minutes were then approved.
One
new member was announced, Jessica Warren of the Carnegie Institution of
Washington, Dept. of Terrestrial Magnetism.
The
following guests were announced: Simon Rexworthy of England, Maria Honeycutt,
the GSA Congressional Fellow, Bob Fraser, USGS Retired who is reenlisting with
GSW, Eli Baker of SAIC, and Meggie Wagner of the Embassy of Germany.
Bill
Burton announced two deaths of former members: George Switzer, formerly of the
Smithsonian, and John Dragonetti, USGS retired and an advisor to AGI. The
Membership stood for a moment of silence. Bill further announced there were
still two more science fairs, one each in Fairfax and Prince Georges Counties.
The audience was told to contact Charna Meth if they are interested in being a
judge for either. Bill also announced the upcoming Virginia State Science Fair
on Saturday, April 12 at George Mason University, and recommended attendance.
Bill
Burton then announced the upcoming spring field trip on June 7th, to be led by
Wayne Newell of the USGS and others, entitled Tidewater Geomorphology at George
Washington’s Birthplace National Monument.
There
were two informal communications, both of them lively:
Roz
Helz, USGS retired, presented “And now for something completely different!
Recent Developments at the Summit of Kilauea Volcano, Hawaii: Three Press
Releases and a New Web Cam.” The bottom line is that Kilauea is finally
changing her behavior after nearly 25 years of eruption, with initial gas
venting and then an explosive eruption from Halemaumau crater. Luckily, the
National Park Service saw fit to close the area to tourists before the
eruption; otherwise there could have been some shattered gin bottles and Madame
Pelee would be truly upset! Bill Burton, Pete Toulmin, and John Eichelberger of
the USGS, E-An Zen of the University of Maryland, and Jamie Allan of NSF asked
questions.
Joe
Smoot of the USGS then gave a report on controversy erupting from the GSW Fall
Field Trip- “The Opening of Iapetus in the Blue Ridge Sedimentary Record.” An
observation at one of the outcrops by Past-President John Slack caused Joe to
undertake further field investigation, which led to a sportsmanlike result that
Joe was both right and wrong. Careful re-observation showed that weathering in
structural features in the Harpers Phyllite of the Chilhowee Formation was
misinterpreted as bedding features; actually, the bloody outcrop is not only
multiply faulted but is structurally upside down as inferred from
cross-bedding. The result, which everybody present agreed upon, is that field
observation is important- armchairs do not lead to solving these sorts of
problems! Bill Burton, USGS, asked one question.
Three
excellent talks followed.
The
first, entitled “Homogeneity/Heterogeneity of the Solar System: Evidence from
Osmium Isotope Cosmochemistry” was given by Tetsuya Yokoyama of the University
of Maryland. Tetsuya gave a primer on chondrite meteorite types, noting that
recent, higher-resolution isotopic measurement showed analytical isotopic
heterogeneity in elements such as Si, Cr, and Ba. These results have led to
interpretations that the solar nebula may have been made heterogeneous by
contributions from pre-solar nebula sources, such as other nearby supernova.
His results on measuring Os isotopes, being very careful to digest completely
the relatively refractory pre-solar grains, showed that the solar nebula was
homogenous with respect to Osmium. Further study showed that incompletely
digesting pre-solar Silicon Carbide might be a source of analytically caused Os
heterogeneity.
Jeff
Grossman of the USGS asked one question.
The
second talk, given by Ingrid Johanson of the USGS Menlo Park, was entitled “New
Methods in Satellite Interferometry for measuring volcano deformation.” Ingrid
gave a tutorial on some of the new methods in Interferometric Synthetic
Aperture Radar (InSAR), describing how to define STAnford Method for
Persistent Scatterers (STAMP) for identification of reference ground sites that
don’t move between successive satellite passes. STAMPs, representing features
such as buildings or bedrock hard points, provide reference for how surrounding
ground has moved. Application to the southern flank of Kilauea Volcano shows
clear evidence for mass movement as a huge slide towards the ocean, and
decrease in elevation at the summit from 2004-2006 before the 2006 inflation
episode, with concomitant increase in elevation towards the coast, reflecting
bulging of the slide toes. Nicks and hummocky patterns shown in InSAR elevation
profiles indicate shallow crustal movements, especially in the vicinity of the
Palis (normal faults) near the Koa’e and Hilina Fracture Zones.
Keith
McLaughlin of SAIC, Dan Milton of USGS (retired), Joe Smoot of the USGS, Eli
Baker of SAIC, and Bill Burton of the USGS asked questions.
The
third talk, given by Dominic Papineau of the Geophysical Laboratory, Carnegie
Institution of Washington, was entitled “Paleoproterozoic Glaciations and the
Rise of Atmospheric Oxygen: What were the Causes?” Dominic addressed why the
Paleoproterozoic become so oxygenated, a key question towards understanding the
evolution of life on Earth. Dominic identified that global glaciation seemed to
be a critical contributor, with punctuated rises in atmospheric oxygen in
interglacial periods. He hypothesized that glaciation is associated with
supercontinental rifting. Such super continental rifting, combined with
glaciation, provided an abundance of weathered, fine grained sediments, and
therefore nutrients for early life (such as phosphorus), to continental
margins. These nutrients caused high biological productivity (as shown by high
13COrg in stromatolitic phosphorites), stimulating microbial sulfate and methane
reduction, and thereby raising atmospheric oxygen and seawater sulfate levels.
Mac
Ross, USGS retired, Bill Burton, USGS, Joe Smoot, USGS, and Jamie Allan, NSF
asked questions.
Acting
President Burton announced the upcoming Bradley Lecture speaker for the 1421st
meeting, and then closed the meeting at 10:05 PM.
Respectfully
submitted,
Mark
A. Engle reading minutes written by Jamie Allan who was acting for Mark A.
Engle
Geological Society of
Washington
Minutes from the 1421st Meeting
Wednesday, April 9, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
At
8:00 PM President Schiffries called to order the 77 attendees. The
minutes of the 1420th meeting were read and approved without any suggestions or
comments.
Several
guests were introduced including John Widener, a student at NOVA CC, Todd
Ballinger, a recent graduate of Western Washington University, Dave and Marilyn
Lindstrom from NASA headquarters, Brian O’Driscoll from University College
Dublin, Sarah Jess - a wife and admirer of fossils, and Thierry Lanz and Carrie
Gill (U of Maryland).
Three
new members were announced, present, and stood without hesitation: Carolyn
Gramling from Geotimes Magazine, Marilyn Lindstrom of NASA headquarters and
David Lindstrom also of NASA Headquarters.
One
formal announcement was made by Charna Meth, Chair of the GSW Public Service
Committee, who announced that 8 GSW members awarded 48 student awards at 7 area
science fairs. President Schiffries thanked Charna for her hard work led
a jovial round of applause. 2nd Vice President, Marilyn Suiter suggested
that recipients of these awards present their science fair exhibits during one
of the GSW meetings. President Schiffries indicated that would happen at
the next meeting.
1st
Vice President Bill Burton then reminded the audience of the upcoming June 7th
GSW field trip.
Doug
Rankin (USGS – retired) presented a video as an informal communication that was
originally to be presented in February by Dick Fisk. The video featured a
time series of the development of a volcanic tropical island as a precursor for
the pinnacle of existence; having a couple of beers on the beach. Several
audience members then felt they needed to engage in further studies on the
topic and partook in a few swigs from the provided liquid refreshments.
Prior
to the very first annual Bradley lecture, President Craig Schiffries presented
a short presentation discussing biographical information and achievements of
Bill Bradley, the namesake of the lecture series. President Schiffries
also gave a pictorial introduction of the speaker, Sean Solomon of the Carnegie
Institutions Department of Terrestrial Magnetism, showing both smiling and
non-smiling phases of Sean which were not wholly unlike those of the
moon.
Sean’s
talk entitled, “MESSENGER’s First Mercury Flyby and What It’s Telling Us about
the Terrestrial Planets” provided an interesting platform to present historic
and recent data on what is “the smallest planet for the last 20 months”.
Much of what was previously known about Mercury had been derived from data
collected during the Mariner 10 flybs in 1974-1975. The Mariner 10
mission allowed for imaging of ~45% of the planet, leaving Mercury to be one of
the least examined bodies in our solar system. The MESSENGER mission was launched
on August 3, 2004 with a purpose of answering 6 guiding scientific questions
pertaining to the geologic history, structure, magnetic field, and volatile
species of Mercury. The first flyby occurred on January 14, 2008 with
additional flybys in October of 2008 and September of 2009 ending with orbit
insertion on March 18, 2011. This trajectory will also involve traveling
around the sun 5 times, thus following a route similar to that the shuttle
driver used on my last trip to the airport and taking nearly as long.
Results from this first flyby through the magnetic field of Mercury suggest
that it has not changed significantly since the Mariner 10 mission and did not
exhibit Mars-like crustal anomalies. Unlike results from the Mariner 10
mission, during this most recent flyby very high energy particles were
noticeably absent near Mercury, although Sean noted that may have been a
function of quiet sun activity in January. Analytical results suggest
that the planet exhibits a significant sodium tail. Images collected from
the previously unseen hemisphere of Mercury suggest that both volcanism and
impact craters were likely sources of material to the plains and that some of
the impact structures may be covered by more recent volcanic flooding.
These images also provided evidence of contractional features, as seen by the
Mariner 10 mission, and that global contractional strain is larger than was
previously thought. The MESSENGER imaging also provided the first full
view of the Caloris basin, which had been partially imaged by Mariner 10.
These new images allowed for identification of grabens radiated from a 40-km
wide crater at the center of the basin. Potential origin mechanisms of
the grabens include basin uplift, impact into a “pre-stressed” floor, or
propagation of radial dikes from a magmatic intrusion. Overall, the results
presented by Sean from the first MESSENGER flyby suggest that Mercury is “a
complex system” and we will all have to wait to see what interesting
discoveries are encountered on the next flyby.
Questions
were asked 1 each by Pete Toulmin (USGS-retired), Bill Burton (USGS), E-An Zen
(University of Maryland), Laurent Montesi (University of Maryland), Jeff
Grossman (USGS), Linda Rowan (AGI), Rich Walker (University of Maryland), and 2
unidentified scientists with gray hair, which does little to distinguish them
from the general GSW population.
Following
a rousing round of applause for the speaker, President Schiffries thanked Jeff
Grossman (USGS), Tim Mock (Carnegie Institution), and Rich Walker (University
of Maryland) for helping get the Bradley lecture series off the ground.
He then announced the program for the upcoming meeting. The meeting was
called to close at 9:39 PM.
Respectfully
submitted,
Mark
A. Engle
Geological Society of Washington
Minutes from the 1422nd Meeting
Wednesday, April 23, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
Prior
to the meeting, local area science GSW award recipients had set up their
projects at the back of the room and presented their research to meeting
attendees. This served as an excellent opportunity for GSW members to
both engage potential future earth scientists and to hastily jot down notes
that could serve as an outline for their own future research grants.
At
7:59 PM President Schiffries called to order the 71 attendees who, it must be
said, were having none of it. As the ruckus subsided, the minutes of the
1421st meeting were read and approved with no corrections or comments.
Despite the presence of many new faces the only guests announced were the GSW
science fair award recipients: Sarah Ruiz Muy from Walker Mill Middle School in
Prince George’s County; Sasha Pfeiffer from Alice Deal Middle School in
Washington, DC; Pradip Ramamurti from White Oak Middle School in Montgomery County;
Alessandro Roux of Yorktown High School in Arlington County; Adam Roberts from
Wilson High School in Washington, DC; and Jai Bapna and Adrien Garnier from
Marshall High School in Fairfax County.
This
was followed by the announcement of two new members: John Weidner, a former
professor of mathematics and currently a student at Northern Virginia Community
College (present); and David Curtiss, the director of the Geoscience and Energy
Office in Washington, DC, for the American Association of Petroleum Geologists
(absent).
Two
informal announcements were communicated: Callan Bentley (Northern
Virginia Community College) invited GSW members to attend an upcoming
wilderness first-aid training course on May 23rd-24th and to see him for more
details. Bill Burton (USGS) also made a reminder of the GSW spring field
trip to George Washington’s Birthplace National Monument in Westmoreland
County, Virginia on June 7th. Interested parties were directed to the GSW
website for more information.
Three
formal talks were presented at the meeting. The first presentation,
“Polymetamorphic history of the Fosdick Migmatite Dome, West Antarctica:
Insights in the evolution on Gondwana,” was given by Fawna Korhonen of the
University of Maryland. (Craig moved that an addition be made here to note that
Fawna does not have a sister named “Flora.”) In this 23-minute presentation,
Fawna presented evidence to suggest 2 separate periods of metamorphism; a
Devonian Carboniferous event that resulted from arc-magmatism on the southern boundary
of Gondwana and a Cretaceous event of renewed activity during continental
rifting. Isochemical phase diagram analysis suggested constraints of
795-865 ºC and 7.3-10.7 kbar for the Devonian-Carboniferous event, based on a
presumed protolith composition, and 820-870 ºC and 6.5-7.5 kbar for the younger
event, using bulk composition. U-Th-Pb dating of monazite grains suggest
dates of 370-340 Ma and 150-115 MA for the two events, respectively.
Questions were asked one each by Bill Burton and Allan Kolker of the USGS and
two each by Brooks Hanson of Science Magazine.
The
second talk, “Baitoushan (Again): Explosive North Korea (Volcanism)” by James
Gill of UC Santa Cruz provided an 24-minute exposition on the continuing work
of US, German, Japanese, and Chinese scientists to research this poorly studied
volcano. Significant eruptions occurred approximately 1 ka (a VEI 7
eruption), 2 ka, and 4 ka (as determined by dating of potassium feldspar
crystals) although written records of the events are notably absent. The
volcano, which sits on the border between China and North Korea contains a
crater lake, similar to the one in Oregon. Melt inclusions from the
millennium eruption contained high concentrations of halogens, which may have
potentially impacted climatic conditions. Results from U-Th isotopes
suggest that late-stage trachyte is out of equilibrium and may have been the
trigger for the millennium eruption. Questions were asked one each by
Craig Schiffries (GSA) and two each by E-an Zen (Univ. of Maryland) and Bill
Burton (USGS).
The
final talk of the evening, “Probing mantle dynamics of the Northwestern United
States: The High Lava Plains Seismic Experiment” by Matthew Fouch of Arizona
State University coming it at just under 21 minutes, completed a hat trick, if
you will, of >20-minute talks for the evening. Matthew’s colorful
presentation included photographic details of installing a seismometer array in
the High Lava Plains which 1) provided hard evidence that geophysicists really
do spend a significant amount of time with their heads in the sand and 2) that
the ability to install a decent wire fence is a critical and respectable skill
for earth scientists. Results from seismic tomography suggest that the
Juan de Fuca slab is intact across the west coast of the US and extends to at
least 500 km in depth. Seismic anisotropy results indicate strong
westward backarc flow in the high plains region and that a rapid change in the
slab dip and location at 400-500 km may provide an opening for upwelling asthenosphere.
Questions were asked 1 each by Bill Burton (USGS), Annie Kammerer (NRC), James
Gill (UC – Santa Cruz), and 2 each by Liz Cottrell (Smithsonian Institution)
and Brooks Hanson (Science Magazine).
President
Schiffries ended the evening by announcing the program for the next meeting and
called the meeting to close at 9:41 PM.
Respectfully
submitted,
Mark
A. Engle
Geological Society of
Washington
Minutes from the 1423rd Meeting
Wednesday, September 10, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
At
8:04pm, President Schiffries called the meeting to order, and the 54 attendees
took their seats. The minutes of the 1422nd meeting where read and approved
with one minor addition. Six visitors were announced: Jack Salima, of the Nuclear
Regulatory Commission; Madalyn Blondes, a soon-to-be post-doctoral researcher
at the University of Maryland, College Park; Aaron Barth, a geology Honors
student at Northern Virginia Community College; Erin Wayman, a reporter for
EARTH magazine (formerly known as Geotimes); Michael Kelly, a program
scientist at NASA headquarters; and David Szymanski, a GSA Congressional
Science Fellow.
Three
new members were announced: Maria Honeycutt, GSA Congressional Science Fellow
(present); and two graduate students in geology at the University of Maryland,
College Park: Noah Miller and Gregory Schofner (both absent).
There
were four announcements: First, Callan Bentley of Northern Virginia Community
College requested that anyone who was interested in teaching introductory
geology courses at NOVA please contact him after the meeting. He also announced
an opportunity to help Cub Scout leaders refine their geology skills, again
followed by an admonition for interested parties to see him after the meeting.
Second, President Schiffries made an announcement on behalf of field trip chair
Bill Burton that the rescheduled Spring field trip would now be the Fall field
trip, and will be held on October 25. Third, Kevin Marvel of the American
Astronomical Society announced that because it is the 400th anniversary of
Galileo’s initial use of a telescope to explore outer space, 2009 has been
declared the International Year of Astronomy by the United Nations. As part of
the celebration, they are distributing cheap, high-quality telescopes that cost
only $10 but are five times better than other telescopes of that price. To help
underwrite the cost of these telescopes, he solicited donations from the crowd.
As a follow-up, President Schiffries pointed out that the chair of another
“international year,” the International Year of Planet Earth, was also in
attendance: Jack Hess, a GSW member.
As
usual, there were three formal talks. The first presentation, by Debra Willard
of the US Geological Survey in Reston, was titled “Paleoecology as a tool for
restoration: Examples from the Florida Everglades.” Using field studies of
different biomes in the Everglades, Debra attempted to figure out how climate
has influenced the distribution of plant and animal communities. Many of the
models being used to manage Everglades restoration fail to consider either past
climate change or predictions of future climate change. Debra’s data led her to
conclude that elevation was a key factor, and that a little bit of elevation
makes a lot of difference to which plants will live there. “Inches,” she
assured us, “do matter.” Constraining when plant communities have shifted was
accomplished by 14C, 210Pb, and 137Cs isotopic
work, as well as the presence of pollen from historically introduced species
like Casuarina. Debra found that the changes observed in the 20th century were
of much greater magnitude than natural variations, and that the fire regime was
strongly altered. In a shocking but satisfying twist of events, restoration
managers are actually using this data to refine their strategy. Questions were
asked one apiece by Naomi Lubick of Environmental Science and Technology; David
Diodato of the U.S. Nuclear Waste Technical Review Board; Richard Walker of the
University of Maryland, College Park; Mac Ross, USGS (retired); Sash
Hier-Majumder of the University of Maryland, College Park; and two questions
from the eternally-two-question-asking Brooks Hansen of Science magazine.
The
second talk was by Stephen Self of the Open University (and now at the U.S. Nuclear
Regulatory Commission). Stephen’s talk was entitled “New insights into flood
basalt super-eruptions.” Switching between compelling imagery of the Columbia
River flood basalts and compelling imagery of the Deccan Traps flood basalts,
Stephen described the challenge of trying to figure out these massive
eruptions. “It’s like an ant trying to decide where to take the first bite out
of an elephant,” he said. Stephen elucidated enormous extrusions, where
individual flows can be over 1000 km3 in extent. Some flows in the
Deccan Traps are inferred to have flowed for over 1000 km in one direction, a
truly superlative statistic. Additional wowing data included the fact that 80%
of the Columbia River flood basalts were erupted within 200 Ka, with a
calculated heat loss of only 20°C over 300 km of flow. How they accomplished
these feats was explained by Stephen’s emplacement model, in which the pahohoe
flows in “sheet lobes” followed by inflation. Questions were asked one apiece
by GSA Congressional Science Fellow David Szymanski; Jim Rubenstone of the
Nuclear Regulatory Commission; Rick Wunderman of the Smithsonian Institution’s
Department of Mineral Sciences; and two apiece by by Naomi Lubick of
Environmental Science and Technology magazine; Lindsay McLellan of the National
Park Service; and (of course) Brooks Hansen of Science magazine.
For
the evening’s final talk, Lucy McFadden of the Astronomy Department at the
University of Maryland, College Park, shared her experiences hunting meteorites
in Antarctica. Under the title of “Expanding our inventory of extra-terrestrial
materials, The Antarctica Search for Meteorites program,” Lucy revealed that
after the Deep Impact Mission concluded, a lack of personal participation in
extraterrestrial collisions led to what she called “post-impact depression.”
Because her next mission in space, the Dawn Mission to Vesta (an asteroid) and
Ceres (a dwarf planet), won’t be happening for several years, Lucy elected to
kill some time by enlisting with the Antarctic Search for Meteorites program,
led by Ralph Harvey of Case Western Reserve University. She described the
travels and logistics of fieldwork on the coldest continent, including how they
keep their tents warm (propane) and what they do for fun (potluck meals in the
party tent). Lucy also shared the teams’ snowmobile-based search procedure in
the Miller Range, and led us in a rousing game of “Spot The Meteorite.” All
told, Lucy and her colleagues found 711 total meteorites on their expedition,
including 70 on one day alone. Questions were asked one apiece by Phil Justus
of the Nuclear Regulatory Commission; Marilyn Lindstrom of NASA (the former
curator of meteorites at Johnson Space Center); Dan Milton, USGS (retired);
Kevin Marvel of the American Astronomical Society; and Jim Rubenstone of the
Nuclear Regulatory Commission. Rick Wunderman of the Smithsonian, evidently
cluing in to an absence of commentary from Brooks Hansen, and asked three
questions, setting a new record for the evening.
President
Schiffries announced the program for the next meeting two weeks hence, and
brought down the gavel at 9:50pm, ending the inaugural meeting of the fall
season.
Respectfully
submitted,
Callan
Bentley
Geological Society of
Washington
Minutes from the 1424th Meeting
Wednesday, September 24, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
President
Schiffries called the meeting to order at 8:02 PM and the 47 attendees took
their seats promptly. The minutes from the 1423rd meeting were read with
one minor correction. The minutes were approved with a uniformly
uninterested groan. Four guests were introduced: Edilene Gomes of the
Geological Survey of Brazil; Dave Szymanski, a GSA congressional fellow;
Merilie Reynolds, a policy intern at AGI; and Jillian Lucher, a former policy
intern at AGI.
Two
formal announcements were given: Bill Burton (USGS) reminded GSW members of the
upcoming GSW fall field trip, formerly known as the spring field trip.
Bill indicated that a headcount of interested parties was necessary well in advance
of the October 25 trip to George Washington’s Birthplace National
Monument. As always, additional information about the field trip can be
found on the GSW web site. President Schiffries announced that the
American Association of Petroleum Geologists Foundation is accepting
nominations for an “Excellence in the Teaching of Natural Resources in the
Earth Sciences K-12” award. Those with potential nominees in mind were
encouraged to contact President Schiffries for additional information and guidance
on the application process.
Madalyn
Blondes, a research assistant at the University of Maryland, College Park, was
announced as a new member and stood with only moderate prompting and prodding.
3±0.5
formal talks were then presented. The first talk of the evening,
“Multiple sulfur isotopes reveal a magmatic origin for the Platreef PGE
deposit, Bushveld Complex, South Africa,” was given by Sarah Penniston-Dorland
of the University of Maryland, College Park. Sarah applied stable isotope
ratios of sulfur to investigate mass dependant and mass independent
fractionation of whole rock sulfur of samples from the Platreef deposit.
Igneous Bushveld rock samples exhibited δ34S of ~1.3-3.2‰ and
Δ33S of near zero while the other end-member, footwall rocks of
the Platreef, displayed much larger mass independent fractionation (Δ33S
~0.5-5‰) and a larger range in δ 34S (~-4 to 16‰). Δ33S
trends along the magma-wall rock contact in 2 different boreholes exhibited a
classis “S” shape into the wall rock which was best modeled by mechanisms of
outward transport with accompanying diffusion. These findings also
suggest, as the title indicates but I need to repeat given the numbers of GSW
members paying less than ideal attention to the reading of the minutes, that
contrary to previous investigations the dominant source of the sulfur in the
Platreef PGE deposit is magmatic, rather than from the country rock.
Questions
were asked one each by Bill Burton (USGS), John Eichelberger (USGS), Pete
Toulmin (USGS-retired), and Craig Schiffries (GSA) and two each by E-an Zen
(University of Maryland) and James Day (University of Maryland). Nick
Woodwood of DOE also tried to get the speaker to discuss the faults of
President Schiffries dissertation work on the Bushveld, but the speaker took no
such bait.
Callan
Bently of Northern Virginia Community College, presented the second talk of the
evening on the “Rise of the geoblogosphere.” Callan indicated that
geology-themed web logs, or geoblogs, first started in 2001 (Andrew’s Geology
Blog at About.com) and began exploding in popularity at around 2005. Mr.
Bently also presented a variety of popular geoblogs in the geoblogosphere
including Arizona Geology, which is written by Lee Allison, the Arizona State
Geologist; RealClimate, a popular forum for discussions of climate science and
change; and “All my faults are stress-related”, a blog which Callan described
as being, “Rock Solid” causing the audience to moan appropriately. Callan
also presented data from a survey of other geobloggers that was hosted on his
geoblog at NOVA. Findings from his survey found that the majority of
bloggers and were graduate students, faculty, and industry consultants
suggesting that government geologists are far too busy, trampled by
bureaucracy, or generally too afraid of the tubes of the internets to actively
geoblog. Callan also found that most geobloggers were blogging from North
America and Europe but the geographic location, language, scope, and number or
geoblogs is expanding in a manner similar to the Cambrian explosion. This
of course leads one to wonder about the possibility and circumstances of
geoblog mass extinctions. At the end of the talk President Schiffries noted
that links to the geoblogs presented in Callan’s talk could be found on the GSW
website.
Questions were asked one each by Sean Brennan (USGS) and 2 each by Bill Burton
(USGS, Craig Schiffries (GSA), and Mac Ross (USGS retired).
The
final talk of the evening, “The fate of subducted continental crust in the
Earth’s mantle: Evidence from the Samoan hotspot,” was given by Matthew Jackson
of the Carnegie Institution’s Department of Terrestrial Magnetism. Being
a fellow Yale graduate, President Schiffries wasted no time to remind GSW
members that he too is an alum. Matthew’s research focused on the apparent
disconnect between the proposed large flux of continental sediments into the
mantle at subduction zones and the lack of crustal trace element and Nd and Sr
isotopic signatures in hotspot lavas. Dr. Jackson showed isotope and trace element
data for hotspot lava samples dredged from the ocean floor near Independent
Samoa that suggested significant crustal input. Two other mechanisms
which could provide the same signatures, namely rapid cycling of Tongan trench
sediments and shallow-level marine sediment assimilation, were discounted based
on paleogeography and lead isotope data. Lastly, Matthew suggested that
recycled continental sediment signatures in lavas are rare because the
subducted sediments are mixed to “smithereens”.
Questions were asked by Bill Burton (USGS) and James Day (University of
Maryland).
President
Schiffries indicated that the schedules of the upcoming meetings could be found
on the GSW website and adjourned the meeting at 9:37PM.
Respectfully
submitted,
Mark
A. Engle
Geological Society of
Washington
Minutes from the 1425th Meeting
Wednesday, October 22, 2008
John Wesley Powell Auditorium
Cosmos Club, Washington, DC
At
8:02 PM, President Craig Schiffries called to order 48 attendees. No
corrections to the minutes of the 1424th meeting were offered and they were
therefore approved, despite the initial inability of the fill-in Secretary, a
dormant petrologist no less, to remember how to say “per mil.” As atonement, he
offers the immortal ditty of the late Harmon Craig:
There was a young man from Cornell
Who pronounced every "delta" as "del”
But the spirit of Urey
Returned in a fury
And transferred that fellow to hell
One
new member was announced, Ediline Gomes, recently arrived from Brazil and
formerly of the University of Orsay.
The
following guests were announced: Dan Doctor of the USGS, Dave Sczymanski of the
USGS and a Congressional Fellow, Richard Yuretich of the NSF, and Rich Thompson
of the University of Arizona, also a Congressional Fellow.
Charna
Meth of the Consortium for Ocean Leadership announced a Marine Geoscience
Leadership Symposium, to be held next March. This symposium is aimed at
developing leadership skills in young scientists.
President
Craig Schiffries announced that the cover photo of the current GSA Today
(Vol. 18, No. 10, October, 2008) was provided by GSW Council member Nora
Noffke, and relates to evidence for the presence of microbial mats some 3
billion years ago, evidence she presented earlier in a GSW talk.
President
Schiffries then reminded members of the GSW Field Trip held Saturday, October
25.
There
were no informal communications.
Three
excellent talks followed.
The
first, entitled “Ground-water depletion: National assessment and global
implications” was given by Leonard Konikow of the USGS, Reston.
Ground-water represents the second largest reservoir of water on our planet,
and is the critical water source for over 50% of the U.S. population. Ground-water
depletion, estimated at 760 cubic km in the 20th Century for the U.S. alone, is
a serious problem not only for lowering of water tables, land subsidence,
permanent compaction of aquifers, and reduced stream flow, but it also
contributes to sea-level rise (accounting for 1-1.5 cm of 20th Century
sea-level rise, or 4-10% of the rise). Importantly, ground-water
depletion from low-permeability confining layers can be substantially greater
than that from confined aquifers. These assessments are challenging to make,
due to the scarcity of data and difficulty in making estimates.
George
Helz of the University of Maryland, E-an Zen of the University of Maryland,
Nick Woodward of DOE, and Craig Schiffries of GSA asked questions.
The
second talk, given by Dionysis Foustokos of the Geophysical Laboratory,
Carnegie Institution of Washington, was entitled “Energy sources in dark
abyssal waters.” Hydrothermal systems at mid-ocean ridges transfer
significant energy from mantle to ocean. Despite being dark, anoxic, toxic (because
of many heavy metals and sulfides), and commonly having very high temperatures,
they nonetheless provide myriad means of supporting chemolithoautotrophic
microbes through electron transfer reactions associated with steep redox, pH,
and temperature gradients. Hydrothermal fluid has lots of electron donors
(such as H2S and CH4) and adjacent seawater has lots of
electron acceptors (such as O2 and Fe(III)). Co-existing microbes
associated with these hydrothermal systems live by catalyzing oxidative or reductive
reactions, reaping subsequent energy rewards. A “reaction trough” at
temperatures of 35-40 degrees C separates high-T reduction reactions and
lower-T oxidation reactions. These systems are modeled by flow-through
(open) and gold cell (closed) experiments, which have shown the importance of
metastable H2O2 (aq) (Hydrogen Peroxide) in hydrothermal
systems, since confirmed by the presence of H2O2-tolerant
microbes at deep-sea vent sites. Future experiments will use flow-through
bioreactors that allow for microbial incubation and variable redox, pH, and T
gradients.
George
Helz of the University of Maryland and Dan Doctor of the USGS asked questions.
The
third talk, given by Igor Puchtel of the University of Maryland, College Park,
was entitled “Re-Os isotope systematics and HSE abundances of the 3.5 Ga
Schapenburg komatiites, South Africa.” Komatiites are ultramafic
lavas with MgO over 18%, range in age from 3.5 Ga to 90 Ma (with the
great majority of Pre-Cambrian age), and represent large degrees of mantle
melting with little differentiation prior to eruption. They extract large
proportions of highly siderophilic elements (HSE) such as Re, Os, Ir, Ru, Pd,
Pt, and Au, reflecting mantle source composition and integrated planetary
accretion, differentiation, melting and recycling processes. Re-Os isotopic
investigation of the Schapensburg komatiites was undertaken as these have
unusually low HSE content, are Al-depleted, and represent the oldest known
komatiitic lavas- thereby carrying evidence for Earth’s primordial silicate
differentiation and early plate tectonic history. The radiogenic 187Os/188Os
and depleted HSE content of the Schapenburg komatiite mantle source is most
consistent with derivation from the base of a crystallized deep mantle magma
ocean, modified by substantial accumulation of majorite and isolated for 1
billion years following formation by the Earth impact which produced the moon.
Alternatively, melting of a hydrous mantle source in a primitive
supra-subduction environment cannot be ruled out.
Jessica
Warren of the Department of Terrestrial Magnetism, Carnegie Institution of
Washington, Roz Helz of the USGS, and Jamie Allan, NSF asked questions.
President
Schiffries announced the upcoming program for the 1426th meeting, and then
closed the meeting at 9:35 PM.
Respectfully
submitted,
Jamie
Allan