Publications
Filter Total Items: 880
Evaluating CO2 and CH4 dynamics of Alaskan ecosystems during the Holocene Thermal Maximum Evaluating CO2 and CH4 dynamics of Alaskan ecosystems during the Holocene Thermal Maximum
The Arctic has experienced much greater warming than the global average in recent decades due to polar amplification. Warming has induced ecological changes that have impacted climate carbon-cycle feedbacks, making it important to understand the climate and vegetation controls on carbon (C) dynamics. Here we used the Holocene Thermal Maximum (HTM, 11–9 ka BP, 1 ka BP = 1000 cal yr before...
Authors
Yujie He, Miriam Jones, Qianlai Zhuang, Christopher Bochicchio, B. Felzer, Erik Mason, Zicheng Yu
The conodont Iapetognathus and its value for defining the base of the Ordovician System The conodont Iapetognathus and its value for defining the base of the Ordovician System
Nicoll et al. (1999, Brigham Young University Geology Studies 44, 27–101) published the taxonomy of species of the ramiform conodont Iapetognathus Landing in Fortey et al. (1982, The Cambrian–Ordovician boundary: sections, fossil distributions, and correlations, National Museum of Wales, Geological Series No. 3, Cardiff, 95–129) and its ancestorIapetonudus Nicoll et al., 1999. Cooper et...
Authors
J. Miller, John Repetski, R. S. Nicoll, G. Nowlan, R. Ethington
Conflict diamonds as an example of natural resource conflict Conflict diamonds as an example of natural resource conflict
No abstract available.
Authors
Peter G. Chirico, Katherine C. Malpeli
Stratigraphy, structure and regional correlation of eastern Blue Ridge sequences in southern Virginia and northwestern North Carolina: an interim report from new USGS mapping Stratigraphy, structure and regional correlation of eastern Blue Ridge sequences in southern Virginia and northwestern North Carolina: an interim report from new USGS mapping
Examination of key outcrops in the eastern Blue Ridge in southern Virginia and northwestern North Carolina is used to evaluate existing stratigraphic and structural models. Recent detailed mapping along the Blue Ridge Parkway and the eastern flank of the Mount Rogers massif provides the opportunity to (1) evaluate legacy data and interpretations and (2) formulate new ideas for regional...
Authors
Mark Carter, Arthur Merschat
North American Commission on Stratigraphic Nomenclature Note 66: records of Stratigraphic Commission, 2003-2013 North American Commission on Stratigraphic Nomenclature Note 66: records of Stratigraphic Commission, 2003-2013
Note 66 summarizes activities of the North American Commission on Stratigraphic Nomenclature (NACSN) from November 2003 to October 2013 and is condensed from the minutes of the NACSN’s 58th to 68th annual meetings1. The purposes of the Commission are to develop statements of stratigraphic principles,recommend procedures applicable to the classification and nomenclature of stratigraphic...
Authors
Robert Easton, Octavian Catuneanu, Art Donovan, Richard Fluegeman, A.P. Hamblin, Howard Harper, Norman Lasca, Jared Morrow, Randall Orndorff, Peter Sadler, Robert Scott, Berry Tew
USGS geologic Mapping and karst research in the Ozark National Scenic Riverways, Missouri, USA USGS geologic Mapping and karst research in the Ozark National Scenic Riverways, Missouri, USA
The Ozark National Scenic Riverways (ONSR) was created in 1964 to protect 134 miles of the Current River and its major tributary, the Jacks Fork, that are located in south-central Missouri (fig. 1). The park includes numerous large karst springs including Big Spring, by flow volume this is the largest spring in the National Park system. The National Park Service (NPS) administers a...
Authors
David Weary, Victoria Grant
Sources and sinks of carbon in boreal ecosystems of interior Alaska: a review Sources and sinks of carbon in boreal ecosystems of interior Alaska: a review
Boreal regions store large quantities of carbon but are increasingly vulnerable to carbon loss due to disturbance and climate warming. The boreal region, underlain by discontinuous permafrost, presents a challenging landscape for itemizing current and potential carbon sources and sinks in the boreal soil and vegetation. The roles of fire, forest succession, and the presence (or absence)...
Authors
Thomas Douglas, Miriam Jones, Christopher Hiemstra
Telescoping metamorphic isograds: Evidence from 40Ar/39A dating in the Orange-Milford belt, southern Connecticut Telescoping metamorphic isograds: Evidence from 40Ar/39A dating in the Orange-Milford belt, southern Connecticut
New 40Ar/39Ar ages for hornblende and muscovite from the Orange-Milford belt in southern Connecticut reflect cooling from Acadian amphibolite facies metamorphism between ∼380 to 360 Ma followed by retrograde recrystallization of fabric-forming muscovite and chlorite during lower greenschist facies Alleghanian transpression at ∼280 Ma. Reported field temperature and pressure gradients are
Authors
Michael Kunk, Gregory Walsh, Martha Growdon, Robert Wintsch
Sea-level change during the last 2500 years in New Jersey, USA Sea-level change during the last 2500 years in New Jersey, USA
Relative sea-level changes during the last ∼2500 years in New Jersey, USA were reconstructed to test if late Holocene sea level was stable or included persistent and distinctive phases of variability. Foraminifera and bulk-sediment δ13C values were combined to reconstruct paleomarsh elevation with decimeter precision from sequences of salt-marsh sediment at two sites using a multi-proxy...
Authors
Andrew Kemp, Benjamin Horton, Christopher Vane, Christopher Bernhardt, D. Corbett, Simon Engelhart, Shimon Anisfeld, Andrew Parnell, Niamh Cahill
Reconnaissance investigation of the rough diamond resource potential and production capacity of Côte d’Ivoire Reconnaissance investigation of the rough diamond resource potential and production capacity of Côte d’Ivoire
Ethnic and political conflict developed into open civil war in Côte d’Ivoire in 2002, leading to a de facto partitioning of the country into the government-controlled south and the rebel-controlled north. Côte d’Ivoire’s two main diamond mining areas, Séguéla and Tortiya, are located in the north, under what was, until recently, rebel-controlled territory. In an effort to prevent...
Authors
Peter G. Chirico, Katherine C. Malpeli
Bedrock geologic and joint trend map of the Pinardville quadrangle, Hillsborough County, New Hampshire Bedrock geologic and joint trend map of the Pinardville quadrangle, Hillsborough County, New Hampshire
The bedrock geology of the Pinardville quadrangle includes the Massabesic Gneiss Complex, exposed in the core of a regional northeast-trending anticlinorium, and highly deformed metasedimentary rocks of the Rangeley Formation, exposed along the northwest limb of the anticlinorium. Both formations were subjected to high-grade metamorphism and partial melting: the Rangeley during the...
Authors
William Burton, Thomas Armstrong
A 600-ka Arctic sea-ice record from Mendeleev Ridge based on ostracodes A 600-ka Arctic sea-ice record from Mendeleev Ridge based on ostracodes
Arctic paleoceanography and sea-ice history were reconstructed from epipelagic and benthic ostracodes from a sediment core (HLY0503-06JPC, 800 m water depth) located on the Mendeleev Ridge, Western Arctic Ocean. The calcareous microfaunal record (ostracodes and foraminifers) covers several glacial/interglacial cycles back to estimated Marine Isotope Stage 13 (MIS 13, ∼500 ka) with an...
Authors
Thomas Cronin, L.V. Polyak, D. Reed, E. Kandiano, R. Marzen, E. Council