Anjana K Shah
Anji Shah is a research geophysicist with the Geology, Geophysics, and Geochemistry Science Center in Denver, CO, specializing in the use of gravity, magnetic and radiometric methods for geologic characterization and interpretation.
She is currently working on several projects involving subsurface geologic characterization for earthquake hazard, mineral resource, and energy resource applications. She also has a background in marine geophysics.
For earthquake hazard studies, Dr. Shah uses gravity and magnetic data to distinguish contacts between subsurface rocks with different densities or magnetic properties. In some regions, these contacts may delineate buried faults and other structures that suggest seismic risk (see this article for application to the 2011 Mw5.8 Mineral, Virginia earthquake). Gravity and magnetic data can also be used to distinguish areas that may be more likely to exhibit seismicity in response to fluid injection (see this article for application to north-central Oklahoma).
Dr. Shah has also led several projects involving imaging and evaluation of rare-earth-element (REE) deposits. Concentrations of REE-bearing minerals in certain geological environments can be detected using radiometric and magnetic methods. Heavy mineral sands are of particular interest because their extraction involves minimal impact; REE-bearing monazite and xenotime have been observed throughout the southeastern U.S. The Eastern Adirondacks were mined in the 1800's and 1900's for magnetite. The ores also contain REE-bearing apatite, and often REE's are present in mining tailings. A combination of geophysical, geological and geochronological approaches is being used to study this area.
Professional Experience
Research Geophysicist, U.S. Geological Survey, 2007-present
Senior Research Scientist, Dynamics Technology, Inc. (now Raytheon Company), 2004-2007
National Research Council Postdoctoral Research Associate, Naval Research Laboratory, 2001-2004
Education and Certifications
Ph.D. Earth and Environmental Sciences, Columbia University, 2001
M.S. Oceanography, University of Washington, 1996
M.S. Applied Mathematics, New York University, 1990
B.S. Mathematics, Stony Brook University, 1988
Abstracts and Presentations
Shah, A., Walsh, G., Taylor, R., Taylor, C., Aleinikoff, J., Klein, A., Regan, S., and Lupulescu, M., 2016, Geophysical, geochemical, and geological approaches to evaluating rare earth resources in the Eastern Adirondacks, upstate New York, Geological Society of America 2016 Annual Meeting, doi: 10.1130/abs/2016AM-281761.
Boyd, O.S. and A. K. Shah, 2016, Progress on the USGS National Crustal Model for seismic hazard studies, Seismological Society of America Annual Meeting, 2016.
Shah, A., R. Stanley, K.A. Lewis, P.J. Haeussler, C.J. Potter, R.W. Saltus and J. Phillips, 2015, Aeromagnetic survey data used to map features of the Cook Inlet and Susitna basins, Alaska, AGU-SEG Workshop "Potential field and electromagnetic methods applied to basin studies," 2015.
Pratt, T., A. Shah, and J.W. Horton, 2014, Discerning Faults Responsible for the Charleston, SC earthquake of 1886, Seismological Society of America Annual Meeting, 2014.
Science and Products
Seismotectonic significance of the 2008–2010 Walloon Brabant seismic swarm in the Brabant Massif, Belgium
Aftershocks illuminate the 2011 Mineral, Virginia, earthquake causative fault zone and nearby active faults
Subsurface geologic features of the 2011 central Virginia earthquakes revealed by airborne geophysics
Deposit model for heavy-mineral sands in coastal environments
Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska
Geological analysis of aeromagnetic data from southwestern Alaska: Implications for exploration in the area of the Pebble porphyry Cu-Au-Mo deposit
Shipboard magnetic field "noise" reveals shallow heavy mineral sediment concentrations in Chesapeake Bay
Shipboard surveys track magnetic sources in marine sediments--geophysical studies of the Stono and North Edisto Inlets near Charleston, South Carolina
Assessment of undiscovered oil and gas resources of the Cook Inlet region, south-central Alaska, 2011
Geophysical, geochemical, and mineralogical data from the Pebble Cu-Au-Mo porphyry deposit area, southwest Alaska: Contributions to assessment techniques for concealed mineral resources
Gravity investigations of the Chesapeake Bay impact structure
Megablocks and melt pockets in the Chesapeake Bay impact structure constrained by magnetic field measurements and properties of the Eyreville and Cape Charles cores
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
- Data
Filter Total Items: 17No Result Found
- Multimedia
- Publications
Filter Total Items: 39
Seismotectonic significance of the 2008–2010 Walloon Brabant seismic swarm in the Brabant Massif, Belgium
Between 12 July 2008 and 18 January 2010 a seismic swarm occurred close to the town of Court-Saint-Etienne, 20 km SE of Brussels (Belgium). The Belgian network and a temporary seismic network covering the epicentral area established a seismic catalogue in which magnitude varies between ML -0.7 and ML 3.2. Based on waveform cross-correlation of co-located earthquakes, the spatial distribution of thAuthorsKoen Van Noten, Thomas Lecocq, Anjana K. Shah, Thierry CamelbeeckAftershocks illuminate the 2011 Mineral, Virginia, earthquake causative fault zone and nearby active faults
Deployment of temporary seismic stations after the 2011 Mineral, Virginia (USA), earthquake produced a well-recorded aftershock sequence. The majority of aftershocks are in a tabular cluster that delineates the previously unknown Quail fault zone. Quail fault zone aftershocks range from ~3 to 8 km in depth and are in a 1-km-thick zone striking ~036° and dipping ~50°SE, consistent with a 028°, 50°SAuthorsJ. Wright Horton, Anjana K. Shah, Daniel E. McNamara, Stephen L. Snyder, Aina M CarterSubsurface geologic features of the 2011 central Virginia earthquakes revealed by airborne geophysics
Characterizing geologic features associated with major earthquakes provides insights into mechanisms contributing to fault slip and assists evaluation of seismic hazard. We use high-resolution airborne geophysical data combined with ground sample measurements to image subsurface geologic features associated with the 2011 moment magnitude (Mw) 5.8 central Virginia (USA) intraplate earthquake and itAuthorsAnjana K. Shah, J. Wright Horton, William C. Burton, David Spears, Amy K GilmerDeposit model for heavy-mineral sands in coastal environments
This report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, through recovery of the minerals ilmenite (Fe2AuthorsBradley S. Van Gosen, David L. Fey, Anjana K. Shah, Philip L. Verplanck, Todd M. HoefenIntegrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska
We combined aeromagnetic, induced polarization, magnetotelluric, and gravity surveys as well as drillhole geologic, alteration, magnetic susceptibility, and density data for exploration and characterization of the Cu-Au-Mo Pebble porphyry deposit. This undeveloped deposit is almost completely concealed by postmineralization sedimentary and volcanic rocks, presenting an exploration challenge. IndivAuthorsAnjana K. Shah, Paul A. Bedrosian, Eric D. Anderson, Karen D. Kelley, James LangGeological analysis of aeromagnetic data from southwestern Alaska: Implications for exploration in the area of the Pebble porphyry Cu-Au-Mo deposit
Aeromagnetic data are used to better understand the geology and mineral resources near the Late Cretaceous Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska. The reduced-to-pole (RTP) transformation of regional-scale aeromagnetic data shows that the Pebble deposit is within a cluster of magnetic anomaly highs. Similar to Pebble, the Iliamna, Kijik, and Neacola porphyry copper occurrences areAuthorsEric D. Anderson, Murray W. Hitzman, Thomas Monecke, Paul A. Bedrosian, Anjana K. Shah, Karen D. KelleyShipboard magnetic field "noise" reveals shallow heavy mineral sediment concentrations in Chesapeake Bay
Shipboard magnetic field data collected over Chesapeake Bay exhibit low-amplitude, short-wavelength anomalies that most likely indicate shallow concentrations of heavy mineral sediments. Piston core layers and black sand beach samples exhibit enhanced magnetic susceptibilities and carry remanent magnetization, with mineralogical analyses indicating ilmenite and trace magnetite and/or maghemite andAuthorsAnjana K. Shah, Peter R. Vogt, Joseph G. Rosenbaum, Wayne L. Newell, Thomas M. Cronin, Debra A. Willard, Rick A. Hagen, John Brozena, Albert HofstraShipboard surveys track magnetic sources in marine sediments--geophysical studies of the Stono and North Edisto Inlets near Charleston, South Carolina
Magnetic field data are traditionally used to analyze igneous and metamorphic rocks, but recent efforts have shown that magnetic sources within sediments may be detectable, suggesting new applications for high-resolution magnetic field surveys. Candidates for sedimentary sources include heavy mineral sand concentrations rich in magnetite or hematite, alteration-induced glauconite, or biogenic magnAuthorsAnjana K. Shah, M. Scott HarrisAssessment of undiscovered oil and gas resources of the Cook Inlet region, south-central Alaska, 2011
The U.S. Geological Survey (USGS) recently completed a new assessment of undiscovered, technically recoverable oil and gas resources in the Cook Inlet region of south-central Alaska. Using a geology-based assessment methodology, the USGS estimates that mean undiscovered volumes of nearly 600 million barrels of oil, about 19 trillion cubic feet of natural gas, and 46 million barrels of natural gasAuthorsRichard G. Stanley, Ronald R. Charpentier, Troy A. Cook, David W. Houseknecht, Timothy R. Klett, Kristen A. Lewis, Paul G. Lillis, Philip H. Nelson, Jeffrey D. Phillips, Richard M. Pollastro, Christopher J. Potter, William A. Rouse, Richard W. Saltus, Christopher J. Schenk, Anjana K. Shah, Zenon C. ValinGeophysical, geochemical, and mineralogical data from the Pebble Cu-Au-Mo porphyry deposit area, southwest Alaska: Contributions to assessment techniques for concealed mineral resources
In 2007, the U.S. Geological Survey began a multidisciplinary study in southwest Alaska to investigate the setting and detectability of mineral deposits in concealed volcanic and glacial terranes. The study area hosts the world-class Pebble porphyry Cu-Au-Mo deposit, and through collaboration with the Pebble Limited Partnership, a range of geophysical and geochemical investigations was carried outAuthorsE. D. Anderson, S. M. Smith, S. A. Giles, Matthew Granitto, R. G. Eppinger, P. A. Bedrosian, A. K. Shah, K. D. Kelley, D. L. Fey, B. J. Minsley, P. J. BrownGravity investigations of the Chesapeake Bay impact structure
The Chesapeake Bay impact structure is a complex impact crater, ??85 km in diameter, buried beneath postimpact sediments. Its main structural elements include a central uplift of crystalline bedrock, a surrounding inner crater filled with impact debris, and an annular faulted margin composed of block-faulted sediments. The gravity anomaly is consistent with that of a complex impact consisting of aAuthorsJ. B. Plescia, D. L. Daniels, A. K. ShahMegablocks and melt pockets in the Chesapeake Bay impact structure constrained by magnetic field measurements and properties of the Eyreville and Cape Charles cores
We use magnetic susceptibility and remanent magnetization measurements of the Eyreville and Cape Charles cores in combination with new and previously collected magnetic field data in order to constrain structural features within the inner basin of the Chesapeake Bay impact structure. The Eyreville core shows the first evidence of several-hundred-meter-thick basement-derived megablocks that have beAuthorsA. K. Shah, D. L. Daniels, A. Kontny, J. BrozenaNon-USGS Publications**
Shah, A. and W. R. Buck, 2006, The rise and fall of axial highs at ridge jumps: Journal of Geophysical Research, 111, B08101, https://doi.org/10.1029/2005JB003657.Shah, A., M.-H. Cormier, W. F. Ryan, W. Jin, J. Sinton, E. Bergmanis, J. Carlut, A. Bradley and D. Yoerger, 2003, Episodic dike swarms inferred from near-bottom magnetic anomaly maps at the southern East Pacific Rise: Journal of Geophysical Research, 108 (B2), 2097, https://doi.org/10.1029/2001JB000564.Shah, A. and W. R. Buck, 2003, Plate bending stresses at axial highs and implications for faulting behavior, Earth and Planetary Science Letters, 211 (3-4), 343-356, https://doi.org/10.1016/S0012-821X(03)00187-0.Cormier, M.-H., W. B. Ryan, A. Shah, W. Jin, A. M. Bradley, D. Yoerger, 2003, Waxing and waning volcanism along the East Pacific Rise on the millennium timescale: Geology, 31 (7), 633-636, https://doi.org/10.1130/0091-7613(2003)031<0633:WAWVAT>2.0.CO;2.Shah, A. and W. R. Buck, 2001, Causes for axial high topography at mid-ocean ridges and the role of crustal thermal structure, Journal of Geophysical Research, 106 (B12), 30865-30879, https://doi.org/10.1029/2000JB000079.Shah, A. and J.-C. Sempéré, 1998, Morphology of the transition from an axial high to a rift valley at the Southeast Indian Ridge, and the relation to variations in mantle temperature: Journal of Geophysical Research,103 (B3), 5203-5223, https://doi.org/10.1029/97JB03110.Géli, L., H. Bougalt, D. Aslanian, A. Briais, L. Dosso, J. Etoubleau, J.-P. LeFormal, M. Maia, H. Ondréas, J.-L. Olivet, C. Richardson, K. Sayanagi, N. Seama, A. Shah, I. Vlastelic, and M. Yamamoto, 1997, Evolution of the Pacific-Antarctic Ridge South of the Udintsev Fracture Zone: Science, 278 (5341), 1281-1284, https://doi.org/10.1126/science.278.5341.1281.Goff, J. A., Y. Ma, A. Shah, J. R. Cochran, and J.-C. Sempéré, 1996, Stochastic analysis of seafloor morphology on the flanks of the Southeast Indian Ridge: The influence of ridge morphology on the formation of abyssal hills: Journal of Geophysical Research, 102 (B7), 15521-15534, https://doi.org/10.1029/97JB00781.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- News
Filter Total Items: 15