Publications
These publications showcase the significant science conducted in our Science Centers.
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A brief review of the construction aggregates market
The U.S. Geological Survey defines the construction aggregates industry as those companies that mine and process crushed stone and/or construction sand and gravel. Aggregates have been used from the earliest times of our civilization for a variety of purposes - construction being the major use. As construction aggregates, crushed stone and construction sand and gravel are the basic raw materials u
Authors
Jason Christopher Willett
Borates
Four minerals represent 90 percent of the borates used by industry worldwide — the sodium borates, tincal and kernite; the calcium borate, colemanite; and the sodium-calcium borate, ulexite.
Authors
R.D. Crangle
Rare earths, the lanthanides, yttrium and scandium
In 2011, rare earths were recovered from bastnasite concentrates at the Mountain Pass Mine in California. Consumption of refined rare-earth products decreased in 2011 from 2010. U.S. rare-earth imports originated primarily from China, with lesser amounts from Austria, Estonia, France and Japan. The United States imported all of its demand for yttrium metal and yttrium compounds, with most of it or
Authors
G. Bedinger, D. Bleiwas
Gypsum
The United States is the world's fourth leading producer and consumer of gypsum. Production of gypsum in the U.S. during 2011 was estimated to be 9.4 Mt (103 million st), an increase of 6 percent compared with 2010 production. The average price of mined crude gypsum was $7/t ($6.35/st). Synthetic gypsum, most of which is generated as a fluegas desulfurization process from coal-fired electric power
Authors
R.D. Crangle
Strontium
In 2011, U.S. apparent consumption of strontium (contained in celestite and manufactured strontium compounds) increased markedly to 18.4 kt (20,300 st) from 10.4 kt (11,500 st) in 2010. Gross weight of imports was 34.4 kt (38,000 st), of which 76 percent originated from Mexico.
Authors
Fold-to-fault progression of a major thrust zone revealed in horses of the North Mountain fault zone, Virginia and West Virginia, USA
The method of emplacement and sequential deformation of major thrust zones may be deciphered by detailed geologic mapping of these important structures. Thrust fault zones may have added complexity when horse blocks are contained within them. However, these horses can be an important indicator of the fault development holding information on fault-propagation folding or fold-to-fault progression. T
Authors
Randall C. Orndorff
Deep Arctic Ocean warming during the last glacial cycle
In the Arctic Ocean, the cold and relatively fresh water beneath the sea ice is separated from the underlying warmer and saltier Atlantic Layer by a halocline. Ongoing sea ice loss and warming in the Arctic Ocean have demonstrated the instability of the halocline, with implications for further sea ice loss. The stability of the halocline through past climate variations is unclear. Here we estimate
Authors
T. M. Cronin, G. S. Dwyer, J. Farmer, H.A. Bauch, R.F. Spielhagen, M. Jakobsson, J. Nilsson, W. M. Briggs, A. Stepanova
Assessing confidence in Pliocene sea surface temperatures to evaluate predictive models
In light of mounting empirical evidence that planetary warming is well underway, the climate research community looks to palaeoclimate research for a ground-truthing measure with which to test the accuracy of future climate simulations. Model experiments that attempt to simulate climates of the past serve to identify both similarities and differences between two climate states and, when compared w
Authors
Harry J. Dowsett, Marci M. Robinson, Alan M. Haywood, Daniel J. Hill, Aisling M. Dolan, Danielle K. Stoll, Wing-Le Chan, Ayako Abe-Ouchi, Mark A. Chandler, Nan A. Rosenbloom, Bette L. Otto-Bliesner, Fran J. Bragg, Daniel J. Lunt, Kevin M. Foley, Christina R. Riesselman
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-strontianite alvikite, and type 2 igneous dikes of
Authors
Robert D. Tucker, Harvey E. Belkin, Klaus J. Schulz, Stephen G. Peters, Forrest Horton, Kim Buttleman, Emily R. Scott
Dinocyst taphonomy, impact craters, cyst ghosts, and the Paleocene-Eocene thermal maximum (PETM)
Dinocysts recovered from sediments related to the Chesapeake Bay impact structure in Virginia and the earliest Eocene suboxic environment in Maryland show strange and intriguing details of preservation. Features such as curled processes, opaque debris, breakage, microborings and cyst ghosts, among others, invite speculation about catastrophic depositional processes, rapid burial and biological and
Authors
Lucy E. Edwards
Antarctic and Southern Ocean influences on Late Pliocene global cooling
The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion
Authors
Robert McKay, Tim Naish, Lionel Carter, Christina Riesselman, Robert Dunbar, Charlotte Sjunneskog, Diane Winter, Francesca Sangiorgi, Courtney Warren, Mark Pagani, Stefan Schouten, Veronica Willmott, Richard Levy, Robert DeConto, Ross D. Powell
Calcareous nannofossil assemblage changes across the Paleocene-Eocene thermal maximum: Evidence from a shelf setting
Biotic response of calcareous nannoplankton to abrupt warming across the Paleocene/Eocene boundary reflects a primary response to climatically induced parameters including increased continental runoff of freshwater, global acidification of seawater, high sedimentation rates, and calcareous nannoplankton assemblage turnover. We identify ecophenotypic nannofossil species adapted to low pH conditions
Authors
Jean M. Self-Trail, David S. Powars, David K. Watkins, Gregory A. Wandless