Publications
Filter Total Items: 880
Conodont biostratigraphy of the Permian-Triassic boundary sequence at Lung Cam, Vietnam Conodont biostratigraphy of the Permian-Triassic boundary sequence at Lung Cam, Vietnam
The occurrences of a few specimens of Clarkina and many specimens of Hindeodus at the Permian-Triassic boundary section at Lung Cam, Vietnam allow accurate graphic correlation to the P-T boundary stratotype at Meishan, China. One species of Clarkina, ten species and two subspecies of Hindeodus, and the apparatuses of Hindeodus latidentatus and Merrillina ultima are described and...
Authors
Bruce Wardlaw, Merlynd Nestell, Galina Nestell, Brooks Ellwood, Luu Thi Phuong Lan
Conodont faunas from a complete basinal succession of the upper part of the Wordian (Middle Permian, Guadalupian, West Texas) Conodont faunas from a complete basinal succession of the upper part of the Wordian (Middle Permian, Guadalupian, West Texas)
In the southern part of the Patterson Hills just to the west of the Guadalupe Mountains escarpment ofWest Texas, a 29m outcrop of alternating calcareous siltstone and silty limestone with a few thin fine sandstone interbeds displays the overlap occurrence of a narrowmorphotype of Jinogondolella nankingensis (herein named J. nankingensis behnkeni) with J. aserrata near its base. The...
Authors
Bruce Wardlaw, Merlynd Nestell
What is the Anthropocene? What is the Anthropocene?
Since Paul Crutzen and Eugene Stoermer introduced the word “Anthropocene” in 2000, scientists and nonscientists alike have used the word to highlight the concept that we are now living in a time when the global environment, at some level, is shaped by humankind rather than vice versa. Humans have significantly altered Earth’s land surface, oceans, rivers, atmosphere, flora, and fauna. By...
Authors
Lucy Edwards
Topographic and Hydrographic GIS Datasets for the Afghanistan Geological Survey and U.S. Geological Survey 2014 Mineral Areas of Interest Topographic and Hydrographic GIS Datasets for the Afghanistan Geological Survey and U.S. Geological Survey 2014 Mineral Areas of Interest
Mineral extraction and associated industries play an important role in the Afghan economy, particularly in the “transitional era” of declining foreign aid and withdrawal of foreign troops post 2014. In addition to providing a substantial source of government revenue, other potential benefits of natural resource development include boosted exports, employment opportunities, and...
Authors
Jessica DeWitt, Peter G. Chirico, Katherine Malpeli
Karst mapping in the United States: Past, present and future Karst mapping in the United States: Past, present and future
The earliest known comprehensive karst map of the entire USA was published by Stringfield and LeGrand (1969), based on compilations of William E. Davies of the U.S. Geological Survey (USGS). Various versions of essentially the same map have been published since. The USGS recently published new digital maps and databases depicting the extent of known karst, potential karst, and...
Authors
David Weary, Daniel Doctor
Geochemistry and origin of metamorphosed mafic rocks from the Lower Paleozoic Moretown and Cram Hill Formations of North-Central Vermont: Delamination magmatism in the western New England appalachians Geochemistry and origin of metamorphosed mafic rocks from the Lower Paleozoic Moretown and Cram Hill Formations of North-Central Vermont: Delamination magmatism in the western New England appalachians
The Moretown Formation, exposed as a north-trending unit that extends from northern Vermont to Connecticut, is located along a critical Appalachian litho-tectonic zone between the paleomargin of Laurentia and accreted oceanic terranes. Remnants of magmatic activity, in part preserved as metamorphosed mafic rocks in the Moretown Formation and the overlying Cram Hill Formation, are a key...
Authors
Raymond Coish, Jonathan Kim, Evan Twelker, Scott P. Zolkos, Gregory Walsh
The Chesapeake Bay impact structure The Chesapeake Bay impact structure
About 35 million years ago, during late Eocene time, a 2-mile-wide asteroid or comet smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and (or) displaced the target rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far...
Authors
David Powars, Lucy Edwards, Gregory S. Gohn, J. Wright Horton
Chesapeake Bay impact structure: A blast from the past Chesapeake Bay impact structure: A blast from the past
About 35 million years ago, a 2-mile-wide meteorite smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and displaced rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far away as Texas and the Caribbean. Large tsunamis...
Authors
David Powars, Lucy Edwards, Gregory S. Gohn, J. Wright Horton
Geologic map of Kundelan ore deposits and prospects, Zabul Province, Afghanistan; modified from the 1971 original map compilations of K.I. Litvinenko and others Geologic map of Kundelan ore deposits and prospects, Zabul Province, Afghanistan; modified from the 1971 original map compilations of K.I. Litvinenko and others
This map and cross sections are redrafted modified versions of the Geological map of the Kundelan ore deposit area, scale 1:10,000 (graphical supplement no. 18) and the Geological map of the Kundelan deposits, scale 1:2,000 (graphical supplement no. 3) both contained in an unpublished Soviet report by Litvinenko and others (1971) (report no. 0540). The unpublished Soviet report was...
Authors
Robert Tucker, Stephen Peters, Will Stettner, Linda Masonic, Thomas W. Moran
On the reconstruction of palaeo-ice sheets: Recent advances and future challenges On the reconstruction of palaeo-ice sheets: Recent advances and future challenges
Reconstructing the growth and decay of palaeo-ice sheets is critical to understanding mechanisms of global climate change and associated sea-level fluctuations in the past, present and future. The significance of palaeo-ice sheets is further underlined by the broad range of disciplines concerned with reconstructing their behaviour, many of which have undergone a rapid expansion since the...
Authors
Chris Stokes, Lev Tarasov, Robin Blomdin, Thomas Cronin, Timothy Fisher, Richard Gyllencreutz, Clas Hattestrand, Jakob Heyman, Richard Hindmarsh, Anna Hughes, Martin Jakobsson, Nina Kirchner, Stephen Livingstone, Martin Margold, Julian Murton, Riko Noormets, W. Peltier, Dorothy Peteet, David Piper, Frank Preusser, Hans Renssen, David Roberts, Didier Roche, Francky Saint-Ange, Arjen Stroeven, James Teller
Accommodation space, relative sea level, and the archiving of paleo-earthquakes along subduction zones Accommodation space, relative sea level, and the archiving of paleo-earthquakes along subduction zones
The spatial variability of Holocene relative sea-level (RSL) change influences the capacities of coastal environments to accommodate a sedimentary record of paleoenvironmental change. In this study we couch a specific investigation in more general terms in order to demonstrate the applicability of the relative sea-level history approach to paleoseismic investigations. Using subsidence...
Authors
Harvey Kelsey, Simon Engelhart, Jessica Pilarczyk, Benjamin Horton, Charles Rubin, Mudrik Daryono, Nazli Ismail, Andrea D. Hawkes, Christopher Bernhardt, Niamh Cahill
Volcanic ash hazards and aviation risk: Chapter 4 Volcanic ash hazards and aviation risk: Chapter 4
The risks to safe and efficient air travel from volcanic-ash hazards are well documented and widely recognized. Under the aegis of the International Civil Aviation Organization, globally coordinated mitigation procedures are in place to report explosive eruptions, detect airborne ash clouds and forecast their expected movement, and issue specialized messages to warn aircraft away from...
Authors
Marianne Guffanti, Andrew Tupper