Publications
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Rapid estimation of minimum depth-to-bedrock from lidar leveraging deep-learning-derived surficial material maps
Previously glaciated landscapes often share similar surficial characteristics, including large areas of exposed bedrock, blankets of till deposits, and alluvium-floored valleys. These materials play significant roles in geologic and hydrologic resources, geohazards, and landscape evolution; however, the vast extents of many previously glaciated landscapes have rendered comprehensive...
Authors
William Elijah Odom, Daniel H. Doctor
Multi-proxy record of ocean-climate variability during the last 2 millennia on the Mackenzie Shelf, Beaufort Sea
A 2,000 year-long oceanographic history, in sub-centennial resolution, from a Canadian Beaufort Sea continental shelf site (60meters water depth) near the Mackenzie River outlet is reconstructed from ostracode and foraminifera faunal assemblages, shell stable isotopes (delta 18O, delta 13C) and sediment biogenic silica. The chronology of three sediment cores making up the composite...
Authors
Laura Gemery, Thomas M. Cronin, Lee W. Cooper, Lucy Roberts, Lloyd D. Keigwin, Jason A. Addison, Melanie Leng, Peigen Lin, Cedric Magen, Marci E. Marot, Valerie Evelyn Schwartz
Unzipping supercontinent Pangea: Geologic, potential field data, and buried structures, and a case for sequential Atlantic opening
Amalgamation of Pangea culminated with zippered N-to-S closing of the Theic ocean during the Alleghanian orogeny. Transpressional-rotational collision produced widespread dextral faulting throughout the eastern Appalachian hinterland, and thrust faulting in the western hinterland and foreland. The partially buried southern Appalachian Eastern Piedmont fault system is a product of late...
Authors
Aaron G. Stubblefield, Robert D. Hatcher, J. Wright Horton, David L. Daniels
Investigating geomorphic change using a structure from motion elevation model created from historical aerial imagery: A case study in northern Lake Michigan, USA
South Manitou Island, part of Sleeping Bear Dunes National Lakeshore in northern Lake Michigan, is a post-glacial lacustrine landscape with substantial geomorphic changes including landslides, shoreline and bluff retreat, and sand dune movement. These changes involve interrelated processes, and are influenced to different extents by lake level, climate change, and land use patterns...
Authors
Jessica D. DeWitt, Francis Ashland
Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA
Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic...
Authors
Mark W. Carter, Ryan J. McAleer, Christopher S. Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
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...
Authors
Daniel E. Kroes, Gregory 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...
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...
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...
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...
Authors
Jesse R. 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...
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 Väliranta, 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 Galka, 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...
Authors
Harry J. Dowsett, Marci M. Robinson, Kevin M. Foley, Timothy D. Herbert, Steve Hunter, Carin Andersson, Whittney Spivey