Publications
Filter Total Items: 830
A comparison of orbital-resolution, Late Pleistocene Alkenone and foraminiferal assemblage-based sea surface temperature reconstructions from the Southwest Pacific
Global and regional reconstructions of past climate conditions often incorporate sea surface temperature (SST) estimates from multiple proxies because not every paleotemperature proxy is applicable in all geographic locations. This practice of assimilating estimates from different proxies in global or regional temperature syntheses makes the implicit assumption that estimates derived from differen
Authors
Emilie A. Henry, Kira T. Lawrence, Laura C. Peterson, Marci M. Robinson
Implementation plan of the National Cooperative Geologic Mapping Program strategy—Great Lakes (Central Lowland and Superior Upland Physiographic Provinces)
IntroductionThe U.S. Geological Survey (USGS) National Cooperative Geologic Mapping Program (NCGMP) has published a strategic plan entitled “Renewing the National Cooperative Geologic Mapping Program as the Nation’s Authoritative Source for Modern Geologic Knowledge”. This plan provides the following vision, mission, and goals for the program for the years 2020–30:Vision: create an integrated, thr
Authors
Christopher S. Swezey, Charles D. Blome, Kevin A. Kincare, Scott C. Lundstrom, Byron D. Stone, Donald S. Sweetkind, Richard C. Berg, Steven E. Brown, John A. Yellich
Regression of the Tethys Sea (central Asia) during middle to late Eocene: Evidence from calcareous nannofossils of western Tarim Basin, NW China
Calcareous nannofossil assemblages from middle to upper Eocene sediments of the western Tarim Basin indicate two important episodes of marine incursion into the basin. The first episode represents a period of shallowing upward in the Wulagen Formation, which is dated as Zone CNE13 (Lutetian) by the co-occurrence of Discoaster bifax, Chiasmolithus solitus, and common Reticulofenestra umbilicus. The
Authors
Xuejiao Wang, Dangpeng Xi, David K. Watkins, Jean Self-Trail, Zihua Tang, Wenxin Cao, Tiantian Jiang, Muhammad Kamran, Xiaoqiao Wan
Evolution and taxonomy of the Paleogene calcareous nannofossil genus Hornibrookina
The genus Hornibrookina consists of enigmatic calcareous nannofossils that first appeared shortly after the K-Pg mass extinction. Due to their relative paucity in most published sections, specimens of this genus have not been previously studied in detail and their paleobiogeographic preferences and evolutionary history have been poorly understood. Biostratigraphic and morphometric analyses of Horn
Authors
Jean Self-Trail, David K. Watkins, James J. Pospichal, Ellen Seefelt
Mapping the extent and methods of small-scale emerald mining in the Panjshir Valley, Afghanistan
Emerald mining in the Panjshir Valley, Afghanistan, has occurred for thousands of years, yet few records exist documenting the detailed spatial extent, techniques, or productivity of small-scale miners. This study proposes new methods to map and monitor the extent and changes in small-scale mining in remote and inaccessible terrain by integrating multispectral remote sensing analysis with archival
Authors
Jessica D. DeWitt, Peter G. Chirico, Kelsey L. O'Pry, Sarah E. Bergstresser
Stop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia
Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained gra
Authors
Mark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. Owens
Stratigraphy and age of a prominent paleosol in a late Pleistocene sedimentary sequence, Mason Neck, Virginia
The High Point paleosol is 2.28-meters-thick aggradational soil developed in fining upward estuarine-alluvial sand and loess. The paleosol is exposed in a few shoreline cliff faces of Mason Neck, Virginia. Although a former A horizon is missing, the E, Bw, Bt, and C horizon sequence seen in the sediments indicates subaerial pedogenesis. Pedogenesis began with initial estuarine-alluvial floodplain
Authors
Helaine W. Markewich, Douglas A. Wysocki, Milan J. Pavich, Joseph P. Smoot, Ronald J. Litwin
The statistical power to detect regional temporal trends in riverine contaminants in the Chesapeake Bay Watershed, USA
Chemical contamination of riverine ecosystems is largely a result of urbanization, industrialization, and agricultural activities occurring on adjacent terrestrial landscapes. Land management activities (e.g., Best Management Practices) are an important tool used to reduce point and non-point sources of pollution. However, the ability to confidently make inferences about the efficacy of land manag
Authors
Tyler Wagner, Paul McLaughlin, Kelly L. Smalling, Sara E. Breitmeyer, Stephanie Gordon, Gregory Noe
The presence of denitrifiers in bacterial communities of urban stormwater best management practices (BMPs)
Stormwater best management practices (BMPs) are engineered structures that attempt to mitigate the impacts of stormwater, which can include nitrogen inputs from the surrounding drainage area. The goal of this study was to assess bacterial community composition in different types of stormwater BMP soils to establish whether a particular BMP type harbors more denitrification potential. Soil sampling
Authors
Natalie Hall, Masoumeh Sikaroodi, Dianna M. Hogan, R. Christian Jones, Patrick Gillevet
Review of ESA SYMP 7: A dynamic perspective on ecosystem restoration–establishing temporal connectivity at the intersection between paleoecology and restoration ecology
Landscape connectivity is vital not only spatially, but also temporally; as ecosystems change, it is important to be aware of past, present, and future variables that may impact ecosystem function and biodiversity. As climate and environments continue to change, choosing appropriate restoration targets is becoming more challenging. By considering the paleoecological and paleoenvironmental record f
Authors
Rachel Reid, Jenny McGuire, Jens-Christiane Svenning, G. Lynn Wingard, David Moreno-Mateos
Calcareous plankton biostratigraphic fidelity and species richness during the last 10 m.y. of the Cretaceous at Blake Plateau, subtropical North Atlantic
Species distributions of well-preserved and diverse assemblages of planktonic foraminifera and calcareous nannofossils spanning the last 10 m.y. of the Cretaceous (middle Campanian through Maastrichtian) are analyzed from samples taken across a 1400 m depth transect at Blake Nose in the western subtropical North Atlantic (Ocean Drilling Program Sites 1049, 1050 and 1052). Age models constructed by
Authors
Brian T. Huber, Nataliya A. Tur, Jean Self-Trail, Kenneth G. MacLeod
The Yorktown Formation: Improved stratigraphy, chronology and paleoclimate interpretations from the U.S. mid-Atlantic Coastal Plain
The Yorktown Formation records paleoclimate conditions along the mid-Atlantic Coastal Plain during the mid-Piacenzian Warm Period (3.264 to 3.025 Ma), a climate interval of the Pliocene in some ways analogous to near future climate projections. To gain insight into potential near future changes, we investigated Yorktown Formation outcrops and cores in southeastern Virginia, refining the stratigrap
Authors
Harry J. Dowsett, Marci M. Robinson, Kevin M. Foley, Timothy D. Herbert