A5043708253- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- High-pressure geophysics and materials
- Hydrocarbon exploration and reservoir analysis
- Geological formations and processes
- Geological and Tectonic Studies in Latin America
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Evolution and Paleontology Studies
- Botany and Geology in Latin America and Caribbean
- Pleistocene-Era Hominins and Archaeology
- Archaeology and Natural History
- Paleontology and Stratigraphy of Fossils
- Hydrology and Sediment Transport Processes
- Groundwater and Isotope Geochemistry
- Landslides and related hazards
- Marine and environmental studies
- Planetary Science and Exploration
- Archaeology and ancient environmental studies
- Astro and Planetary Science
- Methane Hydrates and Related Phenomena
- Soil erosion and sediment transport
- Paleontology and Evolutionary Biology
New Mexico Institute of Mining and Technology
2016-2025
New Mexico Department of Health
2023
New Mexico Bureau of Geology and Mineral Resources
2011-2022
Virginia Tech
2006
University of Helsinki
2002
University of Iowa
2001
University of Buenos Aires
1999
Queen's University
1999
Universidad Nacional de La Plata
1999
University of California, Los Angeles
1990-1996
Research Article| July 01, 2007 Geological records of the Lhasa-Qiangtang and Indo-Asian collisions in Nima area central Tibet Paul Kapp; Kapp 1Department Geosciences, University Arizona, Tucson, Arizona 85721–0077, USA Search for other works by this author on: GSW Google Scholar Peter G. DeCelles; DeCelles George E. Gehrels; Gehrels Matthew Heizler; Heizler 2New Mexico Geochronological Laboratory, New Institute Mining Technology, Socorro, 87801, Lin Ding 3Institutes Tibetan Plateau Geology...
Research Article| June 01, 2006 Tibetan basement rocks near Amdo reveal “missing” Mesozoic tectonism along the Bangong suture, central Tibet Jerome H. Guynn; Guynn 1 Department of Geosciences, University Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Paul Kapp; Kapp Alex Pullen; Pullen Matthew Heizler; Heizler 2New Mexico Bureau Geology and Mineral Resources, New Institute Mining Technology, Socorro, 87801, George Gehrels; Gehrels 3Department...
Research Article| February 01, 2012 Thermochronologic evidence for plateau formation in central Tibet by 45 Ma Alexander Rohrmann; Rohrmann * 1Department of Geosciences, University Arizona, 1040 E 4th Street, Tucson, Arizona 85721, USA *Current address: Institute für Erd- und Umweltwissenschaften, Universität Potsdam, 14476 Germany. Search other works this author on: GSW Google Scholar Paul Kapp; Kapp Barbara Carrapa; Carrapa Peter W. Reiners; Reiners Jerome Guynn; Guynn 2Exxon Mobil...
The Sangiran dome is the primary stratigraphic window for Plio-Pleistocene deposits of Solo basin Central Jawa. has yielded nearly 80 Homo erectus fossils, around 50 which have known findspots. With a hornblende 40 Ar/ 39 Ar plateau age 1.66 ± 0.04 mega-annum (Ma) reportedly associated with two fossils [Swisher, C.C., III, Curtis, G. H., Jacob, T., Getty, A. G., Suprijo, & Widiasmoro (1994) Science 263, 1118–1121), offers evidence that early dispersed to East Asia during earliest...
The correspondence between seismic velocity anomalies in the crust and mantle differential incision of continental-scale Colorado River system suggests that significant mantle-to-surface interactions can take place deep within continental interiors. Rocky Mountain region exhibits low-seismic-velocity associated with atypically high (and rough) topography, steep normalized river segments, areas greatest incision. Thermochronologic geologic data show regional exhumation accelerated starting...
Research Article| February 01, 2003 Controls on architecture of the Late Cretaceous to Cenozoic southern Middle Magdalena Valley Basin, Colombia Elías Gómez; Gómez 1Department Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853, USA Search for other works by this author on: GSW Google Scholar Teresa E. Jordan; Jordan Richard W. Allmendinger; Allmendinger Kerry Hegarty; Hegarty 2Geotrack International, 37 Melville Road, Brunswick West, Victoria 3055, Australia Shari...
Isotopic age determinations ( 40 Ar/ 39 Ar) and associated magnetic polarity stratigraphy for Casamayoran fauna at Gran Barranca (Chubut, Argentina) indicate that the Barrancan “subage” of South American Land Mammal “Age” is late Eocene, 18 to 20 million years younger than hitherto supposed. Correlations radioisotopically dated with Cenozoic geomagnetic time scale faunal levels date within magnetochronologic interval from 35.34 36.62 megannums (Ma) or 35.69 37.60 Ma. This revision constrains...
The Grand Canyon Supergroup records at least two distinct periods of intracratonic extension and sedimentation in the late Mesoproterozoic Neoproterozoic. New 40 Ar/ 39 Ar age determinations indicate that Unkar Group was deposited between ca. 1.2 1.1 Ga. Basins which related northwest-striking faults were created by northeast-southwest extension, contemporaneous with regional northwest-southeast “Grenville” contraction. U-Pb data Neoproterozoic Chuar 800 742 Ma. Sedimentary tectonic studies...
Cordilleran ophiolites typically occur as basement for accreted terranes. In the Klamath Mountains, ophiolitic terranes were progressively by underthrusting beneath North America. The Josephine ophiolite is youngest of and forms a thick Late Jurassic flysch sequence (Galice Formation). This ophiolite‐flysch terrane an east dipping thrust sheet sandwiched between older rocks Mountains above coeval plutonic‐volcanic arc complex below. outcrop pattern roof (Orleans) indicates minimum...
An 40Ar/39Ar age of 45·1 Ma determined for lavas from northern Saipan confirms that these high-silica rhyolites erupted during the 'proto-arc' stage volcanism in Izu–Bonin–Mariana system, which is characterized elsewhere by eruption boninitic lavas. Incompatible trace element concentrations and Sr, Hf, Nd, Pb isotope ratios are transitional between those c. 48 post-38 'first-arc' andesites dacites Rota have typical subduction-related compositions. These compositions modeled crystal...
Abstract Accurately dating Holocene volcanic rocks poses many challenges but is critical to assessing magmatic evolution and hazard risks at highly active volcanoes. Here we use Ra/Th 40Ar/39Ar geochronology date very young eruptions Changbaishan volcano, northeastern China, a recently stratovolcano responsible for one of the most voluminous in past ∼2000 yr. For eruptions, ages are consistently older than those both independently determined maximum ages. Overall, consistent with historical...
This paper documents a multi-stage incision and denudation history for the Little Colorado River (LCR) region of southwestern Plateau over past 70 Ma. The first two pulses are documented by thermochronologic data. Differential Laramide cooling samples on Mogollon Rim suggests carving 70–30 Ma paleotopography N- E-flowing rivers whose pathways were partly controlled strike valleys at base retreating Cretaceous cliffs. A second pulse is apatite (U-Th)/He dates thermal models that indicate...
The 40 Ar/ 39 Ar age spectrum analyses of basalt whole rock and partially degassed sanidine xenocrysts for the Lathrop Wells volcanic center, Nevada, yield eruption ages 77.3 ± 6.0 76.6 4.9 ka (2σ) Ql 1 2 flows, respectively. Basaltic samples were analyzed in four to six replicate runs normally distributed plateau ages. Miocene ash flow tuff xenoliths collected from basaltic units with majority coming . sanidines yielded apparent ( n = 10) ranging 69 17 309 11 a strong cluster 6) at ∼77 ka....