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Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center

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Reconnaissance stratigraphic studies in the Susitna basin, Alaska, during the 2014 field season Reconnaissance stratigraphic studies in the Susitna basin, Alaska, during the 2014 field season

The Susitna basin is a poorly-understood Cenozoic successor basin immediately north of Cook Inlet in south-central Alaska (Kirschner, 1994). The basin is bounded by the Castle Mountain fault and Cook Inlet basin on the south, the Talkeetna Mountains on the east, the Alaska Range on the north, and the Alaska–Aleutian Range on the west (fig. 2-1). The Cenozoic fill of the basin includes...
Authors
David L. LePain, Richard G. Stanley, Nina T. Harun, Kenneth P. Helmold, Rebekah Tsigonis

Composite Sunrise Butte pluton: Insights into Jurassic–Cretaceous collisional tectonics and magmatism in the Blue Mountains Province, northeastern Oregon Composite Sunrise Butte pluton: Insights into Jurassic–Cretaceous collisional tectonics and magmatism in the Blue Mountains Province, northeastern Oregon

The composite Sunrise Butte pluton, in the central part of the Blue Mountains Province, northeastern Oregon, preserves a record of subduction-related magmatism, arc-arc collision, crustal thickening, and deep-crustal anatexis. The earliest phase of the pluton (Desolation Creek unit) was generated in a subduction zone environment, as the oceanic lithosphere between the Wallowa and Olds...
Authors
Kenneth H. Johnson, J.J. Schwartz, Jiri Zak, Krystof Verner, Calvin G. Barnes, Clay Walton, Joseph L. Wooden, James E. Wright, Ronald W. Kistler

Corrigendum to “Comparing activated alumina with indigenous laterite and bauxite as potential sorbents for removing fluoride from drinking water in Ghana” [Appl. Geochem. 56 (2015) 50–66] Corrigendum to “Comparing activated alumina with indigenous laterite and bauxite as potential sorbents for removing fluoride from drinking water in Ghana” [Appl. Geochem. 56 (2015) 50–66]

The authors regret that the application of the t-plot to determine the presence of micropores in the three sorbents needs the following corrections: (1) Fig. 1a, c, e are N2(g) adsorption and desorption isotherms” (remove “BET”). This correction applies to descriptions in the text as well. (2) Table 2, the column titled “Micropores” is mislabelled, and should be labelled “Film thickness”...
Authors
Laura Craig, Lisa L. Stillings, David L. Decker, James M. Thomas

Provenance and detrital zircon geochronologic evolution of lower Brookian foreland basin deposits of the western Brooks Range, Alaska, and implications for early Brookian tectonism Provenance and detrital zircon geochronologic evolution of lower Brookian foreland basin deposits of the western Brooks Range, Alaska, and implications for early Brookian tectonism

The Upper Jurassic and Lower Cretaceous part of the Brookian sequence of northern Alaska consists of syntectonic deposits shed from the north-directed, early Brookian orogenic belt. We employ sandstone petrography, detrital zircon U-Pb age analysis, and zircon fission-track double-dating methods to investigate these deposits in a succession of thin regional thrust sheets in the western...
Authors
Thomas E. Moore, Paul B. O’Sullivan, Christopher J. Potter, Raymond A. Donelick

Structural superposition in fault systems bounding Santa Clara Valley, California Structural superposition in fault systems bounding Santa Clara Valley, California

Santa Clara Valley is bounded on the southwest and northeast by active strike-slip and reverse-oblique faults of the San Andreas fault system. On both sides of the valley, these faults are superposed on older normal and/or right-lateral normal oblique faults. The older faults comprised early components of the San Andreas fault system as it formed in the wake of the northward passage of...
Authors
Russell W. Graymer, Richard G. Stanley, David A. Ponce, Robert C. Jachens, Robert W. Simpson, Carl M. Wentworth

Reconnaissance coal study in the Susitna basin, 2014 Reconnaissance coal study in the Susitna basin, 2014

The Alaska Division of Geological & Geophysical Surveys (DGGS) conducted fieldwork during the summer of 2014 in the Susitna basin as part of an ongoing evaluation of the hydrocarbon potential of frontier basins, particularly those near the Railbelt region (for example, Decker and others, 2013; Gillis and others, 2013). Topical studies associated with this recent work include sedimentary...
Authors
Nina T. Harun, David L. LePain, Rebekah Tsigonis, Kenneth P. Helmold, Richard G. Stanley

Relationships between protein-encoding gene abundance and corresponding process are commonly assumed yet rarely observed Relationships between protein-encoding gene abundance and corresponding process are commonly assumed yet rarely observed

For any enzyme-catalyzed reaction to occur, the corresponding protein-encoding genes and transcripts are necessary prerequisites. Thus, a positive relationship between the abundance of gene or transcripts and corresponding process rates is often assumed. To test this assumption, we conducted a meta-analysis of the relationships between gene and/or transcript abundances and corresponding...
Authors
Jennifer D. Rocca, Edward K. Hall, Jay T. Lennon, Sarah E. Evans, Mark P. Waldrop, James B. Cotner, Diana R. Nemergut, Emily B. Graham, Matthew D. Wallenstein

Can treatment and disposal costs be reduced through metal recovery? Can treatment and disposal costs be reduced through metal recovery?

This paper describes a framework to conduct a “metal-recovery feasibility assessment” for mining influenced water (MIW) and associated treatment sludge. There are multiple considerations in such a determination, including the geologic/geochemical feasibility, market feasibility, technical feasibility, economic feasibility, and administrative feasibility. Each of these considerations...
Authors
Kathleen S. Smith, Linda Figueroa, Geoffrey S. Plumlee

A 3400 year paleolimnological record of prehispanic human–environment interactions in the Holmul region of the southern Maya lowlands A 3400 year paleolimnological record of prehispanic human–environment interactions in the Holmul region of the southern Maya lowlands

The timing, magnitude and drivers of late Holocene environmental change in the Holmul region of the southern Maya lowlands are examined by combining paleoenvironmental and archeological data. Environmental proxy analyses on a ~ 3350 cal yr lacustrine sediment record include pollen, charcoal, loss on ignition, magnetic suscep- tibility, and elemental geochemistry. Archeological evidence...
Authors
David B. Wahl, Francisco Estrada-Belli, Lysanna Anderson

Truncorotalia crassaformis from its type locality: Comparison with Caribbean plankton and Pliocene relatives Truncorotalia crassaformis from its type locality: Comparison with Caribbean plankton and Pliocene relatives

Truncorotalia crassaformis has been identified in Pliocene-Holocene assemblages globally but there has been little analysis of specimens from its type locality at Lomita Quarry, California. This has led to confusion about some diagnostic criteria, particularly the presence of a peripheral keel. To better understand variation specimens are studied from the type locality (Pleistocene, c...
Authors
George H. Scott, James C. Ingle, Brendan McCane, Charles L. Powell, Robert C. Thunell

Brittle Faults Brittle Faults

Brittle shear zones/fault zones are usually defined by curved brittle P-planes bound by usually straight Y-planes. These shears may affect as a narrow zone within the rock bodies. Brittle sheared lenses of rocks vary in geometry, and the P-planes may curve only near the Y-planes. Fault gouge zones sometimes contain P-planes that help to deduce the shear sense. Fault planes/Y-planes may...
Authors
Soumyajit Mukherjee
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