A5047634201- Evolution and Paleontology Studies
- Geology and Paleoclimatology Research
- Pleistocene-Era Hominins and Archaeology
- Animal Ecology and Behavior Studies
- Geomagnetism and Paleomagnetism Studies
- Bat Biology and Ecology Studies
- Paleontology and Evolutionary Biology
- Geological and Geochemical Analysis
- Paleontology and Stratigraphy of Fossils
- Geological formations and processes
- Species Distribution and Climate Change
- Geochemistry and Geologic Mapping
- Wildlife Ecology and Conservation
- Morphological variations and asymmetry
- Archaeology and Natural History
- Botany, Ecology, and Taxonomy Studies
- earthquake and tectonic studies
- Marine and environmental studies
- Isotope Analysis in Ecology
- Plant Diversity and Evolution
- Archaeology and ancient environmental studies
- Plant and Fungal Species Descriptions
- Yersinia bacterium, plague, ectoparasites research
- Insects and Parasite Interactions
- Coastal wetland ecosystem dynamics
University of Arizona
1997-2019
Field Museum of Natural History
2005
University of Portland
1985
Harvard University
1982
National Museums of Kenya
1982
Research Article| January 01, 1975 Magnetic Polarity Stratigraphy of Pliocene-Pleistocene Terrestrial Deposits and Vertebrate Faunas, San Pedro Valley, Arizona NOYE M. JOHNSON; JOHNSON 1Department Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755 Search for other works by this author on: GSW Google Scholar NEIL D. OPDYKE; OPDYKE 2Lamont-Doherty Geological Observatory Department Geology, Columbia University, Palisades, York 10964 EVERETT H. LINDSAY 3Geoscience Department,...
We sampled 150 sites in fine-grained Plio-Pleistocene sediments of the Palm Springs and Imperial Formations. Sampling was confined to 3000 m stratigraphically continuous section containing abundant vertebrate fossil remains Vallecito Creek, Arroyo Seco, Layer Cake local faunas Irvingtonian Blancan Land Mammal Ages. The magnetic stability these sufficient delineate stratigraphy, which ranges from below Cochiti event at base, Matuyama reversed epoch top section. Eight faunal events are placed...
Research Article| November 01, 1983 Rates of late Cenozoic tectonism in the Vallecito–Fish Creek basin, western Imperial Valley, California Noye M. Johnson; Johnson 1Department Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755 Search for other works by this author on: GSW Google Scholar Charles B. Officer; Officer Neil D. Opdyke; Opdyke 2Geology Department, University Florida, Gainesville, Florida 32611 Geoffrey Woodard; Woodard 3Department Geology, State University, Rohnert...
Paleomagnetic samples were collected at 273 sites within a 2012 m continental sedimentary sequence in the Clark's Fork Basin near Powell, Wyoming. The lower 1158 is Polecat Bench Fm while upper 854 Willwood Fm. Although significant secondary components of magnetization present, alternating-field demagnetization to 300 oe peak field revealed polarity primary component natural remanent magnetism. A well-defined zonation observed. dominantly reversed but does contain two normal zones. this...
Carbonatites are igneous rocks formed in the crust by fractional crystallization of carbonate-rich parental melts that mostly mantle derived. They dominantly consist carbonate minerals such as calcite, dolomite, and ankerite, well minor ...Read More
Research Article| March 01, 1982 Upper Cretaceous–Paleocene biostratigraphy and magnetostratigraphy, Hell Creek Tullock Formations, northeastern Montana J. David Archibald; Archibald 1Department of Biology Peabody Museum Natural History, Yale University, New Haven, Connecticut 06520 Search for other works by this author on: GSW Google Scholar Robert F. Butler; Butler 2Department Geosciences, University Arizona, Tucson, Arizona 85721 Everett H. Lindsay; Lindsay William A. Clemens; Clemens...
Cenozoic deposits in many areas of Arizona. Few those fossil vertebrates have been adequately studied and described. Our purpose is to record the occurrence We hope this study will stimulate further research on complex history Lance (1960) summarized vertebrate localities He noted absence from late Cretaceous early Miocene. The now extended back
We present new geochronologic (magnetostratigraphy, fission‐track and 40Ar/39Ar radioisotopic dates, biostratigraphy) data constraining the age of three separate sequences a composite section from Guanajuato, Mexico. Those make this one most complete precisely age‐calibrated in North America spanning Hemphillian/Blancan American Land Mammal "Age" (NALMA) boundary interval, further constrain timing pattern Great Biotic Interchange (GABI). In total, 196 samples (77 sites) were used to...
Detailed paleomagnetic and rock-magnetic analyses have been performed on samples from multiple sections through the Cretaceous/Tertiary (K/T) boundary throughout a 750 m thick sequence of late Cretaceous middle Paleocene continental deposits in San Juan Basin, New Mexico. Curie temperatures determined for magnetic separates 52 levels and, with only two exceptions, they range 180 to 300°C. Along microprobe X-ray these data indicate that detrital ferrimagnetic mineral is titanohematite...