Florence Bascom Geoscience Center

Publications

Filter Total Items: 533
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Year Published: 2013

Diatom evidence for the onset of Pliocene cooling from AND-1B, McMurdo Sound, Antarctica

The late Pliocene, ~ 3.3–3.0 Ma, is the most recent interval of sustained global warmth in the geologic past. This window is the focus of climate reconstruction efforts by the U.S. Geological Survey's Pliocene Research, Interpretation, and Synoptic Mapping (PRISM) Data/Model Cooperative, and may provide a useful climate analog for the...

Riesselman, Christina; Dunbar, R. B.
Christina R. Riesselman, Robert B. Dunbar, Diatom evidence for the onset of Pliocene cooling from AND-1B, McMurdo Sound, Antarctica, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 369, 2013, Pages 136-153, ISSN 0031-0182

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Year Published: 2013

Bedrock geologic map of the Nashua South quadrangle, Hillsborough County, New Hampshire, and Middlesex County, Massachusetts

The bedrock geology of the 7.5-minute Nashua South quadrangle consists primarily of deformed Silurian metasedimentary rocks of the Berwick Formation. The metasedimentary rocks are intruded by a Late Silurian to Early Devonian diorite-gabbro suite, Devonian rocks of the Ayer Granodiorite, Devonian granitic rocks of the New Hampshire Plutonic Suite...

Walsh, Gregory J.; Jahns, Richard H.; Aleinikoff, John N.
Bedrock geologic map of the Nashua South quadrangle, Hillsborough County, New Hampshire, and Middlesex County, Massachusetts; 2013; SIM; 3200; Walsh, Gregory J.; Jahns, Richard H.; Aleinikoff, John N.

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Year Published: 2013

100,000-year-long terrestrial record of millennial-scale linkage between eastern North American mid-latitude paleovegetation shifts and Greenland ice-core oxygen isotope trends

We document frequent, rapid, strong, millennial-scale paleovegetation shifts throughout the late Pleistocene, within a 100,000+ yr interval (~ 115–15 ka) of terrestrial sediments from the mid-Atlantic Region (MAR) of North America. High-resolution analyses of fossil pollen from one core locality revealed a continuously shifting sequence of...

Litwin, Ronald J.; Smoot, Joseph P.; Pavich, Milan J.; Markewich, Helaine Walsh; Brook, George; Durika, Nancy J.
Quaternary Research 80, 2013, 291-315.

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Year Published: 2013

40Ar/39Ar evidence for Late Devonian deformation in the Chester shear zone, east central Maine

No abstract available.

Ghanem, Hind; Kunk, Michael J.; Ludman, Allan; Bish, David; Wintsch, Robert; Biasi, Joseph

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Year Published: 2013

An evaluation of automated GIS tools for delineating karst sinkholes and closed depressions from 1-meter LIDAR-derived digital elevation data

LiDAR (Light Detection and Ranging) surveys of karst terrains provide high-resolution digital elevation models (DEMs) that are particularly useful for mapping sinkholes. In this study, we used automated processing tools within ArcGIS (v. 10.0) operating on a 1.0 m resolution LiDAR DEM in order to delineate sinkholes and closed depressions in the...

Doctor, Daniel H.; Young, John A.
Doctor, D.H. and Young, J.A. (2013) An evaluation of automated GIS tools for delineating karst sinkholes and closed depressions from 1-meter LIDAR-derived digital elevation data. In: Land L, Doctor DH, Stephenson JB, editors, Sinkholes and the Engineering and Environmental Impacts of Karst: Proceedings of the Thirteenth Multidisciplinary Conference, May 6-10, Carlsbad, New Mexico: NCKRI Symposium 2. Carlsbad (NM): National Cave and Karst Research Institute, p. 449-458.

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Year Published: 2013

On the identification of a Pliocene time slice for data–model comparison

The characteristics of the mid-Pliocene warm period (mPWP: 3.264–3.025 Ma BP) have been examined using geological proxies and climate models. While there is agreement between models and data, details of regional climate differ. Uncertainties in prescribed forcings and in proxy data limit the utility of the interval to understand the dynamics of a...

Haywood, Alan M.; Dolan, Aisling M.; Pickering, Steven J.; Dowsett, Harry J.; McClymont, Erin L.; Prescott, Caroline L.; Salzmann, Ulrich; Hill, Daniel J.; Hunter, Stephen J.; Lunt, Daniel J.; Pope, James O.; Valdes, Paul J.

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Year Published: 2013

The Cambrian-Ordovician rocks of Sonora, Mexico, and southern Arizona, southwestern margin of North America (Laurentia): chapter 35

Cambrian and Ordovician shelf, platform, and basin rocks are present in Sonora, Mexico, and southern Arizona and were deposited on the southwestern continental margin of North America (Laurentia). Cambrian and Ordovician rocks in Sonora, Mexico, are mostly exposed in scattered outcrops in the northern half of the state. Their...

Derby, James R.; Fritz, R.D.; Longacre, S.A.; Morgan, W.A.; Sternbach, C.A.; Page, William R.; Harris, Alta C.; Repetski, John E.
The Cambrian-Ordovician rocks of Sonora, Mexico, and southern Arizona, southwestern margin of North America (Laurentia); 2013; Article; Book; The great American carbonate bank: the geology and economic resources of the Cambrian – Ordovician Sauk megasequence of Laurentia (AAPG Memoir 98); Page, W. R.; Harris, A. G.; Repetski, J. E.

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Year Published: 2013

The PRISM (Pliocene Palaeoclimate) reconstruction: Time for a paradigm shift

Global palaeoclimate reconstructions have been invaluable to our understanding of the causes and effects of climate change, but single-temperature representations of the oceanic mixed layer for data–model comparisons are outdated, and the time for a paradigm shift in marine palaeoclimate reconstruction is overdue. The new paradigm in marine...

Dowsett, Harry J.; Robinson, Marci M.; Stoll, Danielle K.; Foley, Kevin M.; Johnson, Andrew L. A.; Williams, Mark; Riesselman, Christina
Dowsett, H.J., Robinson, M.M., Stoll, D.K., Foley, K.M., Johnson, A.L.A., Williams, M., and Riesselman, C.R., 2013, The PRISM (Pliocene Palaeoclimate) reconstruction: Time for a paradigm shift: Philosophical Transactions of the Royal Society, v. 371, p. 1-24.

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Year Published: 2012

Igneous activity, metamorphism, and deformation in the Mount Rogers area of SW Virginia and NW North Carolina: A geologic record of Precambrian tectonic evolution of the southern Blue Ridge Province

Mesoproterozoic basement in the vicinity of Mount Rogers is characterized by considerable lithologic variability, including major map units composed of gneiss, amphibolite, migmatite, meta-quartz monzodiorite and various types of granitoid. SHRIMP U-Pb geochronology and field mapping indicate that basement units define four types of occurrences,...

Tollo, Richard P.; Aleinikoff, John N.; Mundil, Roland; Southworth, C. Scott; Cosca, Michael A.; Rankin, Douglas W.; Rubin, Allison E.; Kentner, Adrienne; Parendo, Christopher A.; Ray, Molly S.
Igneous activity, metamorphism, and deformation in the Mount Rogers area of SW Virginia and NW North Carolina: A geologic record of Precambrian tectonic evolution of the southern Blue Ridge Province; 2012; Book chapter; Book; From the Blue Ridge to the Coastal Plain: Field Excursions in the Southeastern United States; Tollo, Richard P.; Aleinikoff, John N.; Mundil, Roland; Southworth, C. Scott; Cosca, Michael A.; Rankin, Douglas W.; Rubin, Allison E.; Kentner, Adrienne; Parendo, Christopher A.; Ray, Molly S.

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Year Published: 2012

A major light rare-earth element (LREE) resource in the Khanneshin carbonatite complex, southern Afghanistan

The rapid rise in world demand for the rare-earth elements (REEs) has expanded the search for new REE resources. We document two types of light rare-earth element (LREE)-enriched rocks in the Khanneshin carbonatite complex of southern Afghanistan: type 1 concordant seams of khanneshite-(Ce), synchysite-(Ce), and parisite-(Ce) within banded barite-...

Tucker, Robert D.; Belkin, Harvey E.; Schulz, Klaus J.; Peters, Stephen G.; Horton, Forrest; Buttleman, Kim; Scott, Emily R.
A major light rare-earth element (LREE) resource in the Khanneshin carbonatite complex, southern Afghanistan; 2012; Article; Journal; Economic Geology; Tucker, Robert D.; Belkin, Harvey E.; Schulz, Klaus J.; Peters, Stephen G.; Horton, Forrest ; Buttleman, Kim ; Scott, Emily R.

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Year Published: 2012

Ages of pre-rift basement and synrift rocks along the conjugate rift and transform margins of the Argintine Precordillera and Laurentia

New geochronologic data from basement rocks support the interpretation that the Argentine Precordillera (Cuyania) terrane was rifted from the Ouachita embayment of the Iapetan margin of Laurentia. New data from the Ozark dome show a range of ages in two groups at 1466 ± 3 to 1462 ± 1 Ma and 1323 ± 2 to 1317 ± 2 Ma, consistent with existing data...

Thomas, William A.; Tucker, Robert D.; Astini, Ricardo A.; Denison, Rodger E.
Ages of pre-rift basement and synrift rocks along the conjugate rift and transform margins of the Argintine Precordillera and Laurentia; 2012; Article; Journal; Geosphere; Thomas, William A.; Tucker, Robert D.; Astini, Ricardo A.; Denison, Rodger E.