Jun
3
6:00 PM18:00

AGS Meeting (June 3): Refining the Vapor Intrusion Conceptual Model: From Soils to Sewers

Refining the Vapor Intrusion Conceptual Model:  From Soils to Sewers

 Lila Beckley

Abstract

 Vapor intrusion is the migration of volatile organic compounds from contaminated groundwater or soil into buildings.  Because it is a mechanism that could potentially expose people to harmful chemicals, vapor intrusion is scrutinized in a variety of contexts including real estate transactions and regulatory oversight of contaminated site cleanups.  The conventional vapor intrusion conceptual model that has been recognized since the 1990s involves contaminant transport up through the vadose zone into buildings.  In recent years, however, there has been a growing recognition that sewers and utility tunnels can act as preferential pathways for vapor intrusion.  In this talk, I will discuss the evolving vapor intrusion conceptual model including conventional mechanisms, the influence of shallow soils on vapor migration in the subsurface, and the role of sewers/utility tunnels as preferential pathways.  Presenting data from several of GSI’s ESTCP VI research projects, I will also provide recommendations for evaluating sites to determine whether vapor intrusion is a concern. 

 

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 Bio

 Lila Beckley is a senior geologist with GSI Environmental Inc., in Austin, Texas, with more than 24 years of experience in the environmental field.  She received M.A. and B.S. degrees in Geological Sciences from the University of Texas at Austin.  Her current focus areas include regulatory and litigation support, and vapor intrusion.  In the area of vapor intrusion, she has developed investigation protocols through DoD-funded research; conducted assessments of residential, industrial, and military sites around the U.S.; and developed guidance and training.  Prior to joining GSI, Lila worked in enforcement and remediation programs at the Texas Commission on Environmental Quality (TCEQ), in various roles ranging from project to program management.

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May
6
6:00 PM18:00

AGS Meeting (May 6): Extraterrestrial Sed/Strat: Reconstructing the Evolution of a Delta Deposit on Mars

Title: Extraterrestrial Sed/Strat: Reconstructing the Evolution of a Delta Deposit on Mars

 By: Tim Goudge

Summary:

Decades of planetary exploration have revealed widespread evidence for ancient aqueous activity on the surface of Mars, including hydrous alteration minerals, deeply incised valleys, paleolake basins, and fluvio-lacustrine sedimentary deposits. In this talk I will provide an overview of the various lines of evidence for water on early Mars, and discuss outstanding questions on the details of the ancient martian surface environment. I will also present recent work aimed at reconstructing the evolution of a delta deposit within Jezero crater, the landing site for the next NASA rover - the Mars 2020 mission. The Jezero delta is also a representative example of ancient fluvial stratigraphy on Mars, and so these results can help to improve our understanding of the early martian climate and hydrologic cycle.

 

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Tim Goudge

Bio:

Tim Goudge is an Assistant Professor in the Department of Geological Sciences within the Jackson School of Geosciences at the University of Texas at Austin. Dr. Goudge’s scientific interests focus on the role of surface processes in controlling the evolution of planetary landscapes. His research uses remote sensing data to study the signatures of these processes recorded in the topography, mineralogy, and sedimentary rock record of Mars, Earth, and other planetary bodies. Dr. Goudge received a BSc in geological engineering from Queen’s University, and a ScM and PhD from Brown University.

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Apr
1
6:00 PM18:00

AGS Meeting (April 1): AGS Research Symposium

AGS Research Symposium

This event will include poster presentations from the top student posters from the Jackson school and from the Austin Regional Science fair, and will include a cash prize for the winners in each category.

  • $100 for Best PhD Poster

  • $100 for Best Masters Poster

  • $100 for Best Undergraduate Poster

  • $100 for Best High School Poster

Location:

This will likely take place again in the BEG multi purpose room.

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Mar
4
6:00 PM18:00

AGS Meeting (March 4): Investigating the ecological and biogeochemical consequences of water storage in weathered bedrock

Dr. Daniella M Rempe

Assistant Professor, Department of Geological Sciences, Jackson School of Geosciences

Abstract

Many mountainous landscapes are mantled with thin soils that overlie meters to tens of meters of weathered bedrock. This transition zone between soil and bedrock often controls how infiltrating water is partitioned between evapotranspiration and runoff, as well as the rate and pattern of chemical denudation in a landscape. Despite this region’s significance to hydrologic and geomorphic processes, it is largely invisible to observation and the geochemical reactions and hydraulic properties that govern its structural evolution over time are poorly constrained. In this talk, I will present results from an intensive effort to directly quantify the complex fluid and solute pathways in the weathered bedrock region at the Eel River Critical Zone Observatory (ERCZO). We have instrumented an 18 m thick variably saturated argillite weathering profile in the uplifting Northern California Coast Ranges with a series of flexible sensors and samplers that span the continuum from soil to fresh bedrock. In the seasonally dry setting, we observe significant hydrologic dynamics within the weathered bedrock region. Wet-season rainfall passes through unsaturated fractured bedrock before reaching the groundwater table and running off to the adjacent stream. The water that is seasonally stored in the weathered bedrock (rock moisture) is used by plants for transpiration. Using our sampling system, we have collected nearly two years of bi-weekly major and trace ion chemistry from samplers distributed within the weathered bedrock region that separately collect freely draining and tension-held water. We compare water chemistry to in-situ water content and gas phase O2 and CO2 , as well as rock characterization data such as bulk density and elemental composition, to identify controls on the observed solute concentrations. Our preliminary results reveal that both the freely-draining and tension-held waters are seasonally geochemically dynamic, while these same dynamics are dampened or absent in groundwater and streamflow. The tension-held samples show consistently higher concentrations relative to freely draining fluid, suggesting that the dual-domain nature (i.e. flow through matrix and fracture components) of the weathered bedrock system significantly impacts solute generation and weathering of bedrock. We compare our field observations to preliminary 1D reactive transport simulations to explore the role of dual-domain transport on weathering reactions. Our results highlight the coupled nature of geochemical and hydrologic processes in weathered bedrock and the importance of studying this region in Earth’s Critical Zone.

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Bio:

Daniella Rempe is a hydrologist and geomorphologist interested in understanding how the evolution of the near-surface environment drives hydrologic and ecologic processes. She uses a diverse set of hydrological and geophysical field techniques to probe the interior of hillslopes to understand how surface and subsurface processes influence water resources to vegetation, rivers, and the atmosphere. Learn more about Daniella's research interests on the webpage “Rempe Research Group”.

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Feb
25
to Feb 27

AGS Spring 2019 Field Trip: Geology at the Crossroads - Big Bend Ranch State Park, West Texas

  • Big Bend Ranch State Park (map)
  • Google Calendar ICS

Geology at the Crossroads - Big Bend Ranch State Park Presidio and Brewster Counties, West Texas

TRIP DETAILS - COST, PMT DUE DATE pg2_Page_1.jpg
TRIP DETAILS - COST, PMT DUE DATE pg2_Page_2.jpg

Pre- and Post-trip Lodging information:

February 24th (night before departure) and again on February 27th (return to Alpine) participants will need to arrange their own accommodation.

The Quarter Circle 7 Hotel has agreed to block 15 double occupancy (queen beds) rooms. The reduced rate for participants of the AGS Field Trip is $120.60 before taxes, $60.30 per person. If not doubling up please do not request the blocked rooms. Reservations can be made by calling the Quarter Circle 7 Hotel directly at (432) 837 - 1100 and requesting the Austin Geological Society rate. The Hotel Manager's name is Ms. Rebecca Pape.

This location will be the starting and ending points for the trip and all field trip participants will need to assemble there at 7:30 on Monday, February 25th, for prompt departure to Big Bend Ranch State Park. The hotel is located on the West side of town. I have also arranged for monitored parking for all personal vehicles to be left there during the trip. (Hopefully people will be carpooling where possible.) No personnel vehicles will accompany the trip.




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Feb
4
6:00 PM18:00

AGS Meeting (February 4): Neogene Evolution of Central Texas Landscape after Balcones Faulting 

Neogene Evolution of Central Texas Landscape after Balcones Faulting

Dr. Peter R. Rose

click here for handout

The Edwards Plateau and the Balcones Fault Zone (BFZ) dominate the geology and physiography of Central Texas. The Edwards Plateau was formed during Early Miocene time by uplift of the area west and north of the arcuate BFZ. The Albian Edwards Group was a continuous sheet of resistant shallow-shelf carbonate strata that covered all of central Texas: the Edwards Plateau, BFZ, and subsurface of the Central Texas Platform. At the time of first Balcones faulting, the Edwards was widely exposed west and north of the BFZ. Regional headward erosion and dissolution following Balcones faulting progressively stripped away Edwards strata, leaving steep, ragged bluffs that delineated the boundaries of the Edwards Plateau. Just as geological maps outline the Edwards Plateau today, a reconstruction of past Edwards Limestone outcrop locations records the stages of westward and northern erosional retreat through Miocene, Pliocene, Pleistocene and Holocene times.

This integrated geologic/geomorphic/hydrologic account is based upon three different categories of diagrams, prepared specifically for this paper:

  1. A map showing the 26 drainage basins of central Texas;

  2. Stream profiles of 12 rivers sourced from the Edwards Plateau Aquifer, in context with adjacent geologic boundaries of top (tKed) and base (bKed) of the Edwards Group, and base (bK) of Cretaceous formations within the map area;

  3. Seven paleogeographic maps of the Edwards Plateau/BFZ area from onset of Balcones faulting (21 mya) to the present time, showing the location of the Edwards Plateau and the courses of all main streams, in 3.5 my stages.

The sequential evolution of the Central Texas landscape is integrated with independent evidence from five related geological processes and events to generate a holistic account of Edwards Plateau and BFZ history since early Miocene time:

  1. Incised meanders of Edwards Plateau rivers and streams, inboard and peripheral to the BFZ, were probably inherited from early Paleocene conditions, then greatly amplified by Balcones-related uplift.

  2. High porosity and permeability of Edwards strata in the central sector of the BFZ and Edwards Underground Aquifer is related to a) a longer period of increased stream gradients and stream piracy in that sector; b) a wider BFZ with greatest vertical displacement; and c) the presence of a major discharge point at the lowest elevation in the trend, at San Marcos Springs.

  3. Between 14 and 10.5 mya, the Colorado River formed its Great Bend, when it shifted its course about 35 miles north and east, after eroding through Cretaceous strata, downward onto hard, northeast-dipping Paleozoic beds. This shift also generated the marked asymmetry of the Colorado drainage basin, with short tributaries on the east, and long straight tributaries on the west.

  4. Multiple levels of horizontal cave development (youngest downward) in the western Edwards Plateau suggest that the thickness of the Edwards Plateau aquifer was greatest immediately following Balcones faulting, and declined afterward in stages as erosion reduced the area of surface recharge, and increased outflows.

  5. The post-Balcones Medina Arch induced concave-upward stream profiles in streams originating around its apex: Pedernales, Blanco, Guadalupe, Medina, Frio, and East Nueces Rivers.

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Biography

Dr. Pete Rose (Ph. D., Geology, University of Texas, Austin) has been a professional geologist for 59 years, specializing in Carbonate Stratigraphy, Petroleum Geology, E&P Risk Analysis, and Mineral Economics. Before going on his own in 1980 as an independent prospector and consultant, he worked for Shell Oil Company, the United States Geological Survey, and Energy Reserves Group, Inc, a small-cap Independent.

After 10 years as an internationally-recognized authority on economic risking of exploration drilling ventures, he founded Rose & Associates, LLP, in 1998.  His 2001 book, Risk Analysis and Management of Petroleum Exploration Ventures, now in its 7th printing, is considered by many as the “Bible” on that topic, and has been translated into Chinese, Japanese, and Russian.  Pete retired in 2005; Rose and Associates LLP continues as the global standard among consulting companies in that field, providing instruction, software and consulting services on an international scale.

Pete wrote the definitive geological monograph on the Edwards Limestone of Texas (Rose, 1972), and has continued related investigations to the present time -- this will be  his 10th published paper on various aspects of the Edwards Plateau area.  He has authored or co-authored more than 80 published articles on an extremely wide variety of geological topics. He was a Fellow of the Geological Society of America, the American Association for the Advancement of Science, and Geological Society of London.

In 2005 he was the 89th President of the American Association of Petroleum Geologists, In 2006-07 he was deeply involved in successful efforts to encourage the U. S. Securities and Exchange Commission to modernize its rules governing estimation and disclosure of oil and gas reserves, thus facilitating the investment component of the “shale revolution” in the U. S. Pete ws President of the Austin geological Society in 2012/13.

In 2013, the Geological Society of London awarded Peter R. Rose its prestigious Petroleum Group Medal for lifetime contributions to Petroleum Geology, the first American to be so recognized, and in 2014 the American Association of Petroleum Geologists honored him with its Halbouty Outstanding Leadership Award.

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