Publications
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Sediment and nutrient deposition over a reconnected floodplain during large-scale river diversions, the Bonnet Carré spillway in 2011, 2016, and 2019
In hopes of reversing or slowing the decline of the river delta, water diversions have been built and planned, and natural diversions have formed and been allowed to develop along the lower Mississippi River. In addition to the possibility of building land, these diversions allow for the storage of nutrients within the deposited sediments and provide a buffer from coastal storm surge flooding. Dep
Authors
Daniel Kroes, Gregory B. Noe, David Ramirez, Brian Vosburg
The stratigraphy and stratigraphic nomenclature of the Goochland Terrane in the Piedmont Province of east-central Virginia
The Goochland terrane is a structurally isolated crustal block in the eastern Piedmont of Virginia. It is composed of the previously named State Farm Gneiss, Montpelier Anorthosite, Sabot Amphibolite, and Maidens Gneiss, but also includes the Scotchtown Gneiss, Teman Gneiss, and Old Bandana Gneiss which are formally named and defined herein. The eastern part of the Goochland terrane is antiformal
Authors
Robert E. Weems, Eleanora I. Robbins
Planktic foraminifera
Planktic foraminifera are single-celled marine organisms that secrete calcium carbonate tests. They live in the ocean's photic zone, and when they die, their tests, each about the size of a grain of sand, collect on the ocean floor. The geographic distribution of planktic foraminifera is mostly governed by the temperature and salinity of the ocean surface, and species assemblages are generally arr
Authors
Harry J. Dowsett, Marci M. Robinson
Holocene vegetation dynamics of circum-Arctic permafrost peatlands
Vegetation shifts in circum-Arctic permafrost peatlands drive feedbacks with important consequences for peatland carbon budgets and the extent of permafrost thaw under changing climate. Recent shrub expansion across Arctic tundra environments has led to an increase in above-ground biomass, but the long-term spatiotemporal dynamics of shrub and tree growth in circum-Arctic peatlands remain unquanti
Authors
Richard Fewster, Paul J. Morris, Graeme T. Swindles, Ruza F. Ivanovic, Claire C. Treat, Miriam C. Jones
A 600-kyr reconstruction of deep Arctic seawater δ18O from benthic foraminiferal oxygen isotopes and ostracode Mg/Ca paleothermometry
The oxygen isotopic composition of benthic foraminiferal tests (δ18Ob) is one of the pre-eminent tools for correlating marine sediments and interpreting past terrestrial ice volume and deep-ocean temperatures. Despite the prevalence of δ18Ob applications to marine sediment cores over the Quaternary, its use is limited in the Arctic Ocean because of low benthic foraminiferal abundances, challenges
Authors
Jesse Farmer, Katherine Keller, Robert Poirier, Gary S. Dwyer, Morgan Schaller, Helen K Coxall, Matt O'Regan, Thomas M. Cronin
Regional variability in peatland burning at mid-to high-latitudes during the Holocene
Northern peatlands store globally-important amounts of carbon in the form of partly decomposed plant detritus. Drying associated with climate and land-use change may lead to increased fire frequency and severity in peatlands and the rapid loss of carbon to the atmosphere. However, our understanding of the patterns and drivers of peatland burning on an appropriate decadal to millennial timescale re
Authors
Thomas G. Sim, Graeme T. Swindles, Paul J. Morris, Andy J. Baird, Angela V. Gallego-Sala, Yuwan Wang, Maarten Blaauw, Philip Camill, Michelle Garneau, Mark Hardiman, Julie Loisel, Minna Valiranta, Lysanna Anderson, Karina Apolinarska, Femke Augustijns, Liene Aunina, Joannie Beaulne, Přemysl Bobek, Werner Borken, Nils Broothaerts, Qiao-Yu Cui, Marissa A. Davies, Ana Ejarque, Michelle Farrell, Ingo Feeser, Angelica Feurdean, Richard Fewster, Sarah A. Finkelstein, Marie-José Gaillard, Mariusz Gałka, Annica Greisman, Liam Heffernan, Renske Hoevers, Miriam C. Jones, Teemu Juselius, Edgar Karofeld, Klaus Holger Knorr, Atte Korhola, Dmitri Kupriyanov, Malin Kylander, Terri Lacourse, Mariusz Lamentowicz, Martin Lavoie, Geoffrey Lemdahl, Dominika Łuców, Gabriel Magnan, Alekss Maksims, Claudia A. Mansilla, Katarzyna Marcisz, Elena Marinova, Paul J.H. Mathijssen, Dmitri Mauquoy, Yuri Mazei, Natalia Mazei, Julia McCarroll, Robert McCulloch, Alice Milner, Yannick Miras, Fraser J.G. Mitchell, Elena Novenko, Nicolas Pelletier, Matthew Peros, Sanna Pillo, Louis-Martin Pilote, Guillaume Primeau, Damien Rius, Vincent Robin, Mylène Robitaille, Thomas P. Roland, Eleonor Ryberg, A. Britta K. Sannel, Karsten Schittek, Gabriel Servera-Vives, William Shotyk, Michał Słowiński, Normunds Stivrins, Ward Swinnen, Gareth Thompson, Alexei Tiunov, Andrey N. Tsyganov, Eeva-Stiina Tuittila, Gert Verstraeten, Tuomo Wallenius, Julia Webb, Debra A. Willard, Zicheng Yu, Claudio Zaccone, Hui Zhang
The relative stability of planktic foraminifer thermal preferences over the past 3 million years
Stationarity of species’ ecological tolerances is a first-order assumption of paleoenvironmental reconstruction based upon analog methods. To test this and other assumptions used in quantitative analysis of foraminiferal faunas for paleoceanographic reconstruction, we analyzed paired alkenone unsaturation ratio (UK′37) 37′) sea surface temperature (SST) estimates and relative abundances of plankt
Authors
Harry J. Dowsett, Marci M. Robinson, Kevin M. Foley, Timothy D. Herbert, Steve Hunter, Carin Andersson, Whittney Spivey
Pollen records, postglacial: Southeastern North America
Pollen records from the unglaciated southeastern region of North America provide an overview of biogeographic changes associated with vegetational migration northward following the retreat of the Laurentide Ice Sheet. Changing insolation during the Holocene affected forest composition on the Coastal Plain, and rising sea level controlled the distribution of marsh and forested wetlands throughout t
Authors
Debra A. Willard
Poleward amplification, seasonal rainfall and forest heterogeneity in the Miocene of the eastern USA
Paleoclimate reconstructions can provide a window into the environmental conditions in Earth history when atmospheric carbon dioxide concentrations were higher than today. In the eastern USA, paleoclimate reconstructions are sparse, because terrestrial sedimentary deposits are rare. Despite this, the eastern USA has the largest population and population density in North America, and understanding
Authors
Tammo Reichgelt, Aly Baumgartner, Ran Feng, Debra A. Willard
Detection and monitoring of small-scale diamond and gold mining dredges using synthetic aperture radar on the Kadéï (Sangha) River, Central African Republic
Diamond and gold mining has been practiced by artisanal miners in the Central African Republic (CAR) for decades. The recent introduction of riverine dredges indicates a transition from artisanal/manual digging and sorting techniques to small-scale mining methods. This study implements a remote sensing analysis of Synthetic Aperture Radar (SAR) data to map gold and diamond dredges operating on the
Authors
Marissa Ann Alessi, Peter G. Chirico, Sindhuja Sunder, Kelsey L. O'Pry
A recently discovered trachyte-hosted rare earth element-niobium-zirconium occurrence in northern Maine, USA
Reported here are geological, geophysical, mineralogical, and geochemical data on a previously unknown trachyte-hosted rare earth element (REE)-Nb-Zr occurrence at Pennington Mountain in northern Maine, USA. This occurrence was newly discovered by a regional multiparameter, airborne radiometric survey that revealed anomalously high equivalent Th (eTh) and U (eU), confirmed by a detailed ground rad
Authors
Chunzeng Wang, John F. Slack, Anjana K. Shah, Martin G. Yates, David R. Lentz, Amber T.H. Whittaker, Robert G. Marvinney
A novel non-destructive workflow for examining germanium and co-substituents in ZnS
A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of s
Authors
Sarah M. Hayes, Ryan J. McAleer, Nadine M. Piatak, Sarah Jane White, Robert R. Seal