GSW: 2008 MEETING MINUTES
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.
Mark A. Engle
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.
Jamie Allan for Mark A. Engle
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.
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.
Mark A. Engle reading minutes written by Jamie Allan who was acting for Mark A. Engle
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.
Mark A. Engle
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.
Mark A. Engle
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.
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.
Mark A. Engle
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.