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Publications

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Impact of Late Holocene climate variability and anthropogenic activities on Biscayne Bay (Florida, U.S.A.): Evidence from diatoms

Shallow marine ecosystems are experiencing significant environmental alterations as a result of changing climate and increasing human activities along coasts. Intensive urbanization of the southeast Florida coast and intensification of climate change over the last few centuries changed the character of coastal ecosystems in the semi-enclosed Biscayne Bay, Florida. In order to develop management po
Authors
Anna Wachnicka, Evelyn Gaiser, G. Lynn Wingard, Henry Briceño, Peter Harlem

Preventing the trade of conflict diamonds and supporting artisanal mining

Because of this association between the richness of a deposit and its geomorphology, high-resolution DEMs are a critical dataset in developing alluvial geomorphic models of the deposit zones.
Authors
Peter G. Chirico, Katherine C. Malpeli

A volcanic activity alert-level system for aviation: Review of its development and application in Alaska

An alert-level system for communicating volcano hazard information to the aviation industry was devised by the Alaska Volcano Observatory (AVO) during the 1989–1990 eruption of Redoubt Volcano. The system uses a simple, color-coded ranking that focuses on volcanic ash emissions: Green—normal background; Yellow—signs of unrest; Orange—precursory unrest or minor ash eruption; Red—major ash eruption
Authors
Marianne C. Guffanti, Thomas Miller

Late Pleistocene and Holocene uplift history of Cyprus: implications for active tectonics along the southern margin of the Anatolian microplate

The nature of the southern margin of the Anatolian microplate during the Neogene is complex, controversial and fundamental in understanding active plate-margin tectonics and natural hazards in the Eastern Mediterranean region. Our investigation provides new insights into the Late Pleistocene uplift history of Cyprus and the Troodos Ophiolite. We provide isotopic (14C) and radiogenic (luminescence)
Authors
R. W. Harrison, E. Tsiolakis, B. D. Stone, A. Lord, J. P. McGeehin, S. A. Mahan, P. Chirico

Laurentian origin for the North Slope of Alaska: Implications for the tectonic evolution of the Arctic

The composite Arctic Alaska–Chukotka terrane plays a central role in tectonic reconstructions of the Arctic. An exotic, non-Laurentian origin of Arctic Alaska–Chukotka has been proposed based on paleobiogeographic faunal affinities and various geochronological constraints from the southwestern portions of the terrane. Here, we report early Paleozoic trilobite and conodont taxa that support a Laure
Authors
J. V. Strauss, F. A. Macdonald, J. F. Taylor, John E. Repetski, W. C. McClelland

Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

Predominantly clastic, off-lapping, transgressive, near-shore marine sediment packages that are morphologically expressed as subparallel NE-trending barriers, beach ridges, and associated back-barrier areas, characterize the near-surface stratigraphic section between the Savannah and the Ogeechee Rivers in Effingham County, southeastern Georgia. Each barrier/back-barrier (shoreline) complex is low
Authors
H. W. Markewich, M.J. Pavich, A. P. Schultz, S. A. Mahan, W. B. Aleman-Gonzalez, P.R. Bierman

Chronology from sediment cores collected in southwestern Everglades National Park, Florida

Age model data are presented for 10 cores from the southwestern coastal mangrove zone of Everglades National Park, Florida, collected in Common Era (CE) 2004 and 2005 and used for paleoecological analysis. Carbon-14 (14C), lead-210 (210Pb), cesium-137 (137Cs), radium-226 (226Ra), and pollen biostratigraphic information is included, and age models were generated for 6 of the 10 cores. Age reversals
Authors
C.E. Bernhardt, G.L. Wingard, D. A. Willard, M. E. Marot, B. Landacre, C. W. Holmes

Surficial geologic map of the Mount Grace-Ashburnham-Monson-Webster 24-quadrangle area in central Massachusetts

The surficial geologic map shows the distribution of nonlithified earth materials at land surface in an area of 24 7.5-minute quadrangles (1,238 mi2 total) in central Massachusetts. Across Massachusetts, these materials range from a few feet to more than 500 ft in thickness. They overlie bedrock, which crops out in upland hills and as resistant ledges in valley areas. The geologic map differentiat
Authors
Janet Radway Stone

Reevaluation of the Piermont-Frontenac allochthon in the Upper Connecticut Valley: Restoration of a coherent Boundary Mountains–Bronson Hill stratigraphic sequence

The regional extent and mode and time of emplacement of the Piermont-Frontenac allochthon in the Boundary Mountains–Bronson Hill anticlinorium of the Upper Connecticut Valley, New Hampshire–Vermont, are controversial. Moench and coworkers beginning in the 1980s proposed that much of the autochthonous pre–Middle Ordovician section of the anticlinorium was a large allochthon of Silurian to Early Dev
Authors
Douglas W. Rankin, Robert D. Tucker, Yuri Amelin

Lateglacial and Holocene climate, disturbance and permafrost peatland dynamics on the Seward Peninsula, western Alaska

Northern peatlands have accumulated large carbon (C) stocks, acting as a long-term atmospheric C sink since the last deglaciation. How these C-rich ecosystems will respond to future climate change, however, is still poorly understood. Furthermore, many northern peatlands exist in regions underlain by permafrost, adding to the challenge of projecting C balance under changing climate and permafrost
Authors
Stephanie D. Hunt, Zicheng Yu, Miriam C. Jones

Upper crustal structure of Alabama from regional magnetic and gravity data: Using geology to interpret geophysics, and vice versa

Aeromagnetic and gravity data sets obtained for Alabama (United States) have been digitally merged and filtered to enhance upper-crustal anomalies. Beneath the Appalachian Basin in northwestern Alabama, broad deep-crustal anomalies of the continental interior include the Grenville front and New York–Alabama lineament (dextral fault). Toward the east and south, high-angle discordance between the no
Authors
Mark G. Steltenpohl, J. Wright Horton, Robert D. Hatcher, Isidore Zietz, David L. Daniels, Michael W. Higgins

Where fast weathering creates thin regolith and slow weathering creates thick regolith

Weathering disaggregates rock into regolith – the fractured or granular earth material that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA). A priori, we predicted that the regolith on diabase would be thicker than on granite because the dominant miner
Authors
Ekaterina Bazilevskaya, Marina Lebedeva, Milan J. Pavich, Susan L. Brantley, Gernot Rother, Dilworth Y. Parkinson, David Cole