Category Archives: PGS

Potomac Geophysical Society

PGS: Geology and Public Policy – Recent Issues in Virginia

The February 19, 2015 meeting of the Potomac Geophysical Society will be held at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Geology and Public Policy – Recent Issues in Virginia

David B. Spears, State Geologist

Virginia Department of Mines, Minerals and Energy

Government decision makers are faced with difficult choices when it comes to public policy regarding energy and mineral resources. Our nation is heavily dependent on fossil fuels, radioactive isotopes, and rare earth elements that often must be imported from foreign countries to meet U.S. demand. Even though developing our own domestic supplies has obvious strategic advantages, such development often conflicts with other societal priorities such as environmental protection and social justice. To further complicate matters, conflicting pressure is brought to bear on policy makers by an uninformed or misinformed populace that is generally anti-development, and by pro-development businesses who have a financial interest in resource development. In this presentation, Virginia’s State Geologist will use recent, Virginia-specific examples such as uranium mining, offshore drilling, and shale gas to highlight the ways in which government-based geoscientists play a unique role in providing scientific guidance in public debates about how to best manage our nation’s energy and mineral resources.

David Spears is the State Geologist of Virginia, a position residing in the Department of Mines, Minerals, and Energy. He is responsible for coordinating the work of the Division of Geology and Mineral Resources, a small group of geoscientists focused on mapping Virginia’s geology, mineral resources, energy resources, and geologic hazards such as earthquakes, landslides, and sinkholes. In recent years, the State Geologist has played an increasing role in responding to public policy issues such as offshore drilling, natural hazards, and hydraulic fracturing. David received a B.S. in Geology from Lafayette College and a M.S. in Geology from Virginia Tech. He began his professional career in the petroleum industry before coming to Virginia state government in 1993. A native of New Jersey, he currently resides in Buckingham County in central Virginia. In 2012, David received the Bradley Prize from the Geological Society of Washington for his presentation about geology and public policy.

Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS January meeting: Electromagnetic Survey of Potomac River headwaters

The January 15, 2015 meeting of the Potomac Geophysical Society will be held January 15 at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Electromagnetic Survey of the Headwaters of North Branch of Potomac River, Important Tributaries, and Impacting Mines

Paul Petzrick, Maryland Power Plant Research Program, Annapolis, Maryland

In 1999, the National Energy Technology Laboratory (NETL) acquired a Helicopter Electromagnetic Survey (HEM) of the Kempton/Coketon Mine Complex for the Maryland Power Plant Research Program (PPRP). NETL’s interest was in studying remote sensing as a means of identifying water quality problems from mining, and PPRP’s interest was in planning geoengineering projects to permanently restore water quality in streams degraded by abandoned pre-law mines. The 1999 HEM revealed important benefits and limitations of this type of survey that might now be performed by drones. The data from the 1999 survey is particularly important when coupled with other data collected for PPRP by Garrett College and the Western Maryland Regional GIS Center in understanding the massive two-State, 64 square kilometer, surface and underground mine complex that disturbs the headwaters of the Potomac River.

Mr. Petzrick’s presentation will discuss interpretation of the HEM data, the importance of software for conversion of the data to useful graphics for planning restoration projects, and alternate methods of remote sensing and their conversion to useful graphics. The data and its interpretation in each case has been the subject of significant review by NETL and its support contractor and similarly by experts at PPRP’s support contractor, Environmental Resources Management, Inc. The importance of historical information and utilization of water quality data as a tool in assessing environmental issues will also be addressed.

Biography

Paul Petzrick is a Senior Engineer and Scientist at the Maryland Power Plant Research Program (PPRP) with a focus on Civil and Environmental Engineering. He has been with this Program in the Maryland Department of Natural Resources for 23 years after finishing 30 years of Federal service that included 20 years as a Navy Civil Engineer Corps officer and 7 years of Senior Executive Service at the U.S. Department of Energy. He had applied mathematics education at the University of Wisconsin and has Engineering Degrees from the U.S. Naval Academy, RPI, and Princeton (M.S. 1966). At PPRP he is primarily responsible for the beneficial use of by-products (ash and CO2) of producing electricity.

Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Evolution of the Beaufort Sea

The October 16, 2014 meeting of the Potomac Geophysical Society will be held October 16 at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Seismic Evidence for the Geologic Evolution of the Alaska Beaufort Sea and Adjacent Canada Basin

Dave Houseknecht, U.S. Geological Survey, Reston, Virginia

Integration of 2-D reflection seismic, gravity, and sparse exploration well data from the offshore Alaska Beaufort shelf and slope provides new perspectives on the dynamic tectonic evolution of this Arctic margin. The Beaufort shelf is considered a rift shoulder that developed during Jurassic to Early Cretaceous opening of the Canada Basin, and previous work considered much of the pre-Cretaceous stratigraphy to have been eroded beneath the breakup unconformity. However, reprocessed and newly collected seismic data demonstrate the presence of highly attenuated crust and Jurassic to Lowermost Cretaceous syn-rift strata beneath much of the shelf. Moreover, older strata are present beneath the syn-rift succession, and these include Upper Paleozoic and perhaps Triassic strata, the latter of which may include oil-prone source rocks.

The north-vergent front of the Brooks Range thrust belt is extant beneath the eastern Beaufort shelf, and forms a tectonic wedge and syntectonic wedge-top basin system active since the Paleocene. Upper Paleozoic to Cretaceous strata are deformed by thrust faults and folds within this wedge, and reconstruction of syn-rift extension is difficult as a result. Paleocene through Pliocene strata display a spectrum of growth geometry beneath the shelf and slope, a reflection of syntectonic wedge-top deposition.

This ongoing research contributes to a better understanding of the tectonic evolution of the Alaska Arctic margin, and of the petroleum potential of the region. The results are being used to inform policy makers regarding a disputed maritime boundary between the U.S. and Canada, as well as potential extended continental shelf claims under the U.N. Convention on the Law of the Sea.

Biography

Dave Houseknecht is a research geologist with the U.S. Geological Survey (USGS) with a focus on basin analysis, geological controls of petroleum resource distribution, and petroleum resource assessment. This work is mainly concentrated in Arctic Alaska and adjacent Arctic regions. He frequently represents the USGS scientific perspective on petroleum resources in ANWR, NPRA, and other areas of Alaska and the global Arctic to the Administration and Congress. Dave joined the USGS in 1992, serving as Energy Program Manager through 1998 and then moving to a research position. Previously, Houseknecht was a professor of geology at the University of Missouri (1978-1992) and consultant to the oil industry (1981-1992), working on domestic and international projects. He received geology degrees from Penn State University (Ph.D. 1978, B.S. 1973) and Southern Illinois University (M.S. 1975).

Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Crustal-Scale Mass and Heat Transfer During the Run-up to a Super Eruption

The May, 2014, meeting of the Potomac Geophysical Society will be held May 15th at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Crustal-Scale Mass and Heat Transfer During the Run-up to a Super Eruption, James E. Quick1, Silvano Sinigoi2, Gabriella Demarchi2, Ian Richards1, Rita Economos3 (1Huffington Department of Earth Sciences, Southern Methodist University, Box 750395, Dallas, TX 75205. 2Dipartimento di Scienze della Terra, Università di Trieste, via Weiss 8, 34127 Trieste, Italy. 3Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095-1567

Abstract: A virtually complete crustal section in the Sesia Valley of northwest Italy provides a unique opportunity to directly constrain crustal-scale transfer of mass and heat beneath a continental volcanic system. Capping the section, a bimodal volcanic complex containing a >15-km-diameter rhyolitic caldera is intruded by a 7- to 8-km-thick granitic pluton that is rooted in migmatitic paragneiss at mid-crustal levels. An 8-km-thick gabbroic body, “magmatically underplated” at >15 km depth, intrudes the paragneiss. Consistent with a cause-and-effect relationship between magmatic underplating in the deep crust and silicic plutonism and volcanism at high crustal levels, SHRIMP U/Pb zircon ages for volcanic, granitic and underplated gabbroic rocks cluster within a relatively narrow time window of ~290 to ~280 Ma. A Concordia age of 282 + 0.75 Ma on zircons from the caldera ignimbrite indicates that caldera formation occurred late in the evolution of this magmatic system. Field relations and geochemistry constrain the thermal history of the Sesia section and the processes of magmatic underplating, crustal anatexis and assimilation, and hybridization during its magmatic evolution. Magmatic underplating was accommodated by crustal extension, which is recorded by structures produced by the flow of gabbroic cumulates downward and away from a small magma chamber perched near the top of the intrusion. Heat from the underplated gabbro induced anatexis in country-rock paragneiss, producing granitic melts that migrated higher in the crust. Eu and Ba enrichments, εNd < -2.5, 87Sr/86Sr >0.7075, and δ18O > 8 indicate that the parental melt of the underplated gabbro had ingested ~24% to 40% assimilant consisting of paragneiss previously stripped of a granitic component. Peraluminous compositions of the granitic and volcanic rocks indicate that anatectic melting of metapelitic paragneiss was a contributing source, but 87Sr/86Sr ~ 0.710 and whole-rock δ18O ranging from 10 to 11.5 are intermediate between the compositions of the paragneiss (87Sr/86Sr ~ 0.715 and δ18O from 11 to >15) and the underplated gabbro, indicating that late-stage, residual melts produced by fractional crystallization of the underplated gabbro also contributed to the formation of granite and silicic volcanic rocks. A 1-D, finite-difference thermal model utilizing these constraints and incorporating advection and energy-constrained assimilation reproduces the thicknesses of lithologies observed in the field and indicates that: (1) focused delivery of mantle melt was efficient in driving anatexis in overlying crustal rocks, (2) migration of anatectic melts to the upper crust was efficient in removing heat from the underplated gabbro and restricting its thermal impact on the overlying crust, and (3) growth of lower- and upper-crustal plutons involved incremental assembly under conditions favoring creation of large volumes of crystal mush rather than large classic magma chambers.

Bio:  James E. Quick is the Associate Vice President for Research, Dean of Graduate Studies, and Professor of Earth Sciences at Southern Methodist University (SMU). Prior to his appointment at SMU, he was employed by the US Geological Survey for 27 years in various capacities including Team Chief Scientist for the Eastern Regional Geologic Mapping and Earth Surface Processes Teams, and Program Coordinator for the Volcano Hazards Program. He earned a BSc in Geology at UCLA, an MSc in Mineralogy and Petrology at the University of Minnesota, and a PhD in Geology at Caltech. For the last 25 years, Professor Quick’s research has focused on the Sesia Valley in northern Italy as a natural laboratory to understand the processes that influence the composition and the formation of igneous rocks. In this area, he and his Italian colleagues have demonstrated that tilting and uplift during the Alpine orogeny exposed the magmatic system beneath a Permian supervolcano to an unprecedented depth of >25 km. These results, which were recognized by the Geological Society of Italy with the Capellini Medal in 2010, led to the creation of a UNESCO Geopark in 2013, and resulted in Professor Quick’s induction in January as an honorary citizen of Borgosesia, the principal city of the Sesia Valley. In his presentation, Professor Quick will use boundary conditions developed in the Sesia Valley to address crustal-scale mass transfer and thermal evolution within an evolving magmatic system during the lead up to a super eruption.

Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001540-888-3001 or via E-mail at fraser.robert@comcast.net.If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email tofraser.robert@comcast.net.

PGS: Space Geodesy Project

The April, 2014, meeting of the Potomac Geophysical Society will be held April 17th at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

Abstract: NASA’s Space Geodesy Project, Stephen M. Merkowitz, NASA Goddard Space Flight Center, Greenbelt, MD: NASA’s Space Geodesy Project (SGP) recently completed a prototype core site as the basis for a next generation Space Geodetic Network that is part of NASA’s contribution to the Global Geodetic Observing System (GGOS). This system is designed to produce the higher quality data required to establish and maintain the Terrestrial Reference Frame and provide information essential for fully realizing the measurement potential of the current and future generation of Earth Observing spacecraft. The prototype core site is at NASA’s Geophysical and Astronomical Observatory at Goddard Space Flight Center and includes co-located, state of-the-art, systems from all four space geodetic observing techniques: Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). A system for monitoring of the “ties” between these four systems is an integral part of the core site development concept and this specific prototype. When fully implemented, this upgraded global network will benefit in addition to the ITRF, all other network products (e.g. precision orbit determination, local & regional deformation, astrometry, etc.) that will also be improved by at least an order of magnitude, with concomitant benefits to the supported and tracked missions, science projects, and engineering applications. This presentation will summarize the results of the prototype site demonstration and provide the motivation and plans for NASA’s next generation geodetic network.

Biography:  Stephen Merkowitz is a scientist and project manager at NASA Goddard Space Flight Center. His research interests include: fundamental tests of General Relativity, lunar and interplanetary laser ranging, and space geodesy. He received his PhD in Physics from Louisiana State University working on gravitational wave antennas, and continued this research for two years in Frascati, Italy on a National Institute for Nuclear Physics (INFN) fellowship. In 1998 he became a Research Associate at the University of Washington where he performed experimental tests of General Relativity and measurements of Newton’s gravitational constant (which remains the most precise measurement of “big G” to date). In 2000, he moved to NASA Goddard to serve as Deputy Project Scientist for the LISA Project, a space based gravitational wave mission. In 2009, Merkowitz went on a yearlong detail to the Executive Office of the President covering Physical Science and Engineering for the Office of Science and Technology Policy, followed by a detail at NASA Headquarters as Assistant Director of the Astrophysics Division. He returned to Goddard in 2011 and now manages NASA’s Space Geodesy Project and is Principal Investigator for the Global Positioning System Laser Retroreflector Array.

Meeting Room and Dining Arrangements: We now meet in the glassed-in room at the back of the main dining room—The Fife and Drum. We order individually from the Club menu, which has a nice variety of dinner offerings. We pay a single bill (I pay it with my Officers Club credit card), so we collect at least $25 from each diner with the agreement, that if one orders more than $20 in food and drink, he adds the amount over $20 to his contribution. The $5 overcharge goes to the Room Fee, Tax, Gratuity, and the Speaker’s Dinner. We collect on the Honor System. We did this throughout the last year, and it worked well. This room change and use of the menu have greatly reduced the loss that we have incurred in the past for having fewer than 20 people dining, and the change has preserved the viability of using the Officers Club for our meetings.

Reception at 6:00. Order Dinner at 7:00. Talk at 8:30 PM. Please note that the meal orders will be taken at 7:00. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001540-888-3001 or via E-mail at fraser.robert@comcast.net.If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email tofraser.robert@comcast.net.

PGS: Lyle Mars on ASTER-mapping

Title: Hydrothermal alteration mapped using ASTER data, and how the hydrothermal alteration maps are applied to define potential economic deposit targets and to assess volcano debris flow hazards.

Speaker: John Carlyle Mars (Nickname Lyle) was born and raised in Mobile, Alabama and received his B.S. and M.S. degrees from the University of Alabama and a Ph.D. from the University of Kentucky. Lyle has worked for the last 16 years at the U.S. Geological Survey in the Eastern Mineral and Environmental Resources Science Center in Reston, Virginia. Lyle’s primary focus is the spectroscopic study and mapping of rocks and minerals associated with economic mineral deposits using multispectral and hyperspectral imaging instruments.

 

Abstract: Hydrothermally altered rocks contain clays and hydrous silica that exhibited diagnostic Al-OH and O-H spectral absorption features in the short wave infrared region (SWIR). Hydrothermally altered rocks are typically associated with economic deposits of copper, gold, silver, and molybdenum. In addition, hydrothermal alteration weakens volcanic slopes on volcanoes and increases the potential for debris flows and avalanches. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operator algorithms have been used to map hydrothermal alteration on volcanic edifices and to regionally map volcanic and magmatic arcs in order to identify targets of potential economic deposits in Iran, Pakistan, Afghanistan, Kazakhstan and the central and southern parts of the U.S. Basin and Range. Mineral map units of hydrothermal alteration features include hydrothermal silica, calcite-dolomite and epidote-chlorite (propylitic), alunite-pyrophyllite-kaolinite (argilllic), sericite-muscovite (phyllic) and jarosite. This talk will show how hydrothermal alteration is mapped using ASTER data, and how the hydrothermal alteration maps are applied to define potential economic deposit targets and to assess volcano debris flow hazards.

Meeting Room and Dining Arrangements: We now meet in the glassed-in room at the back of the main dining room—The Fife and Drum. We order individually from the Club menu, which has a nice variety of dinner offerings. We pay a single bill (I pay it with my Officers Club credit card), so we collect at least $25 from each diner with the agreement, that if one orders more than $20 in food and drink, he adds the amount over $20 to his contribution. The $5 overcharge goes to the Room Fee, Tax, Gratuity, and the Speaker’s Dinner. We collect on the Honor System. We did this throughout the last year, and it worked well. This room change and use of the menu have greatly reduced the loss that we have incurred in the past for having fewer than 20 people dining, and the change has preserved the viability of using the Officers Club for our meetings.

Reception at 6:00. Order Dinner at 7:00. Talk at 8:30 PM. Please note that the meal orders will be taken at 7:00. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.

PGS: Pratt on New Madrid

The February, 2014, meeting of the Potomac Geophysical Society will be held February 20th at the Fort Myer Officers’ Club in Arlington, VA (http://www.jbmhhmwr.com/index/Maps_and_Directions.html) in the Glassed-in room in the Fife and Drum (main dining room).

“The New Madrid seismic zone: Structure, earthquake potential and the debate over building codes” by Thomas L. Pratt, Ph.D., U.S. Geological Survey, Reston, VA,

The New Madrid Seismic Zone (NMSZ) area of the Central U.S. has seen Cambrian to Ordovician rifting and subsequent compression, subsidence and shearing. The southern arm of the NMSZ is coincident with the anticlinal Blytheville Arch (BA), which seismic reflection data presented here indicate is a pop-up structure within a strike-slip fault system along the Cambrian graben’s axial fault. The BA has perhaps the densest concentrations of faults in the region, but numerous faults that cut shallow (Eocene?) strata outside of the BA indicate that earthquakes have not been restricted to the NMSZ. Modern seismicity outlines the Reelfoot fault stepover in the strike-slip New Madrid fault system (NMFS), and comparison with the fault pattern in analog models of stepovers and restraining bends suggests that deformation caused by this stepover controls the extent of NMSZ seismicity. About 4.3 to 5 km of post-Eocene(?) slip on the southern arm of the NMSZ can be estimated from apparent shearing of the southern portion of Crowley’s Ridge, a north-trending, fault-bounded topographic ridge. This apparent displacement of Crowley’s Ridge suggests that slip extends south of the NMSZ. Only a small fraction of this long-term slip is expressed as uplift above the Reelfoot reverse fault, suggesting that strike-slip motion on the southern arm of the NMSZ continues north of the Reelfoot fault. The NMFS thus appears to be part of a broad set of strike-slip faults that spans the Reelfoot rift, with long-term slip continuing north and south of the modern seismic zone.

Meeting Room and Dining Arrangements: We now meet in the glassed-in room at the back of the main dining room—The Fife and Drum. We order individually from the Club menu, which has a nice variety of dinner offerings. We pay a single bill (I pay it with my Officers Club credit card), so we collect at least $25 from each diner with the agreement, that if one orders more than $20 in food and drink, he adds the amount over $20 to his contribution. The $5 overcharge goes to the Room Fee, Tax, Gratuity, and the Speaker’s Dinner. We collect on the Honor System. We did this throughout the last year, and it worked well. This room change and use of the menu have greatly reduced the loss that we have incurred in the past for having fewer than 20 people dining, and the change has preserved the viability of using the Officers Club for our meetings.

Reception at 6:00. Order Dinner at 7:00. Talk at 8:30 PM. Please note that the meal orders will be taken at 7:00. Allow 15 minutes for security entering Ft. Myer as all civilian vehicles are searched. To ensure access to and from Fort Myer use the Hatfield Gate, open 24 hours a day (http://www.jbmhhmwr.com/index/Maps_and_Directions.html). Reservations are not necessary, however, we need a head count, so, if you wish to attend dinner ($25), please inform Bob Fraser at 540-888-3001 or via E-mail at fraser.robert@comcast.net. If you wish, please feel free to attend the talk without dinner. Non-members and guests are welcome. Visit the PGS web site at http://www.potomacgeophysical.com for new meeting announcements, etc. Please send changes of address or email to fraser.robert@comcast.net.