Publications
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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 The original maps and cross sections are contained in unpublished Soviet report no. 0290 (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
Characterizing meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey
Meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey remain undocumented despite a history of damaging slope movement extending back to at least 1903. This study applies an empirical approach to quantify the rainfall conditions leading to shallow landsliding based on analysis of overlapping historical prec
Authors
Francis Ashland, Alex R. Fiore, Pamela A. Reilly
Shallow marine response to global climate change during the Paleocene-Eocene Thermal Maximum, Salisbury Embayment, USA
The Paleocene-Eocene Thermal Maximum (PETM) was an interval of extreme warmth that caused disruption of marine and terrestrial ecosystems on a global scale. Here we examine the sediments, flora, and fauna from an expanded section at Mattawoman Creek-Billingsley Road (MCBR) in Maryland and explore the impact of warming at a nearshore shallow marine (30–100 m water depth) site in the Salisbury Embay
Authors
Jean Self-Trail, Marci M. Robinson, Timothy J. Bralower, Jocelyn A. Sessa, Elizabeth A. Hajek, Lee R. Kump, Sheila M. Trampush, Debra A. Willard, Lucy E. Edwards, David S. Powars, Gregory A. Wandless