Publications
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Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins
Deglacial (12.8–10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberi
Authors
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov
Biostratigraphic and morphometric analyses of specimens from the calcareous nannofossil genus Tribrachiatus
Biostratigraphic and morphometric analyses of calcareous nannofossil assemblages from one outcrop and two cored sections of lower Eocene sediments reveal the presence of two new species: Tribrachiatus lunatus sp. nov., and Tribrachiatus absidatus sp. nov. Differences between the new species and Tribrachiatus orthostylus are discussed. The first occurrence of the two new species is just below the
Authors
Jean Self-Trail, Ellen Seefelt, Claire L. Shepherd, Victoria A. Martin
Geologic map of the Dusar area, Herat Province, Afghanistan; Modified from the 1973 original map compilations of V.I. Tarasenko and others
The geologic maps and cross sections presented in this report are redrafted and modified versions of the Geologic map and map of useful minerals of the Dusar area (scale 1:50,000) and Geologic sketch map of the Dusar and Namak-sory ore occurrences (scale 1:10,000), located in the Herat Province, Afghanistan. The original maps and cross sections are contained in unpublished Soviet report no. 0290 (
Application of paleoecology to ecosystem restoration: A case study from south Florida’s estuaries
Paleoecological analyses of biotic assemblages from cores collected throughout south Florida’s estuaries indicate gradually increasing salinities over approximately the last 2000 years, consistent with rising sea level. Around the beginning of the twentieth century these gradual patterns of change began to shift, corresponding to the beginning of human alteration of the environment via canal const
Authors
G. Lynn Wingard
A transect through Vermont’s most famous volcano – Mount Ascutney: GSNH Summer 2017 Field Trip
No abstract available.
Authors
Gregory J. Walsh
New insight into the origin of manganese oxide ore deposits in the Appalachian Valley and Ridge of northeastern Tennessee and northern Virginia, USA
Manganese oxide deposits have long been observed in association with carbonates within the Appalachian Mountains, but their origin has remained enigmatic for well over a century. Ore deposits of Mn oxides from several productive sites located in eastern Tennessee and northern Virginia display morphologies that include botryoidal and branching forms, massive nodules, breccia matrix cements, and fra
Authors
Sarah K. Carmichael, Daniel H. Doctor, Crystal G. Wilson, Joshua Feierstein, Ryan J. McAleer
Hypogene caves of the central Appalachian Shenandoah Valley in Virginia
Several caves in the Shenandoah Valley in Virginia show evidence for early hypogenic conduit development with later-enhanced solution under partly confined phreatic conditions guided by geologic structures. Many (but not all) of these caves have been subsequently invaded by surface waters as a result of erosion and exhumation. Those not so affected are relict phreatic caves, bearing no relation to
Authors
Daniel H. Doctor, Wil Orndorff
Linkages and feedbacks in orogenic systems: An introduction
Orogenic processes operate at scales ranging from the lithosphere to grain-scale, and are inexorably linked. For example, in many orogens, fault and shear zone architecture controls distribution of heat advection along faults and also acts as the primary mechanism for redistribution of heat-producing material. This sets up the thermal structure of the orogen, which in turn controls lithospheric rh
Authors
J. Ryan Thigpen, Richard D. Law, Arthur J. Merschat, Harold Stowell
Temporal and spatial distribution of Paleozoic metamorphism in the southern Appalachian Blue Ridge and Inner Piedmont delimited by ion microprobe U-Pb ages of metamorphic zircon
Ion microprobe U-Pb zircon rim ages from 39 samples from across the accreted terranes of the central Blue Ridge, eastward across the Inner Piedmont, delimit the timing and spatial extent of superposed metamorphism in the southern Appalachian orogen. Metamorphic zircon rims are 10–40 µm wide, mostly unzoned, and dark gray to black or bright white in cathodoluminescence, and truncate and/or embay in
Authors
Arthur J. Merschat, Brendan R. Bream, Matthew T. Huebner, Robert D. Hatcher, Calvin F. Miller
Source of salinity in the Broken Hill (Australia) Pb-Zn-Ag deposit: Insights from halogen ratios in fluid inclusions
Ratios of Na/Br, Br/Cl, and I/Cl were determined on leachates of fluid inclusions from the Broken Hill Pb-ZnAg deposit in Australia. Paragenetic relations suggest that whereas all analyzed inclusions formed during or after regional metamorphism, ion ratios are not greatly changed from those of the pre-metamorphic ore-forming fluids. Based on relatively high Br/Cl and I/Cl ratios, and low Na/Br rat
Authors
John F. Slack, D.A. Banks, R.T. Wilkin
Reconstructing Common Era relative sea-level change on the Gulf Coast of Florida
To address a paucity of Common Era data in the Gulf of Mexico, we reconstructed ~ 1.1 m of relative sea-level (RSL) rise over the past ~ 2000 years at Little Manatee River (Gulf Coast of Florida, USA). We applied a regional-scale foraminiferal transfer function to fossil assemblages preserved in a core of salt-marsh peat and organic silt that was dated using radiocarbon and recognition of pollutio
Authors
Matthew J. Gerlach, Simon E. Engelhart, Andrew C. Kemp, Ryan P. Moyer, Joseph M. Smoak, Christopher E. Bernhardt, Niamh Cahill
Post-glacial flooding of the Bering Land Bridge dated to 11 cal ka BP based on new geophysical and sediment records
The Bering Strait connects the Arctic and Pacific oceans and separates the North American and Asian landmasses. The presently shallow ( ∼ 53 m) strait was exposed during the sea level lowstand of the last glacial period, which permitted human migration across a land bridge today referred to as the Bering Land Bridge. Proxy studies (stable isotope composition of foraminifera, whale migration into
Authors
Martin Jakobsson, Christof Pearce, Thomas M. Cronin, Jan Backman, Leif G. Anderson, Natalia Barrientos, Goran Bjork, Helen Coxhall, Agatha de Boer, Larry Mayer, Carl-Magnus Morth, Johan Nilsson, Jayne Rattray, Christian Sranne, Igor Semiletov, Matt O'Regan