Publications
Filter Total Items: 919
Root biomass and productivity in coastal swamp forests of Louisiana (USA) Root biomass and productivity in coastal swamp forests of Louisiana (USA)
Coastal swamp forests (CSF) occupy approximately 225,000 ha in Southeastern Louisiana (USA), and across a large percentage of this area, CSF are subjected to sediment starvation, salinity intrusion, and chronic submergence. We assessed root biomass and productivity in nine CSF in Louisiana, and found that root biomass ranged from 420.8 g m−2 to 1712.2 g m−2 to a soil depth of 30 cm. Root...
Authors
Ken W. Krauss, Jorge A. Villa, Blair A. Miller, Eric J. Ward, Andrew S. From, Gregory B. Noe
Creating 3D point clouds, digital elevation models, and orthomosaics from historical aerial imagery through structure from motion aided photogrammetry Creating 3D point clouds, digital elevation models, and orthomosaics from historical aerial imagery through structure from motion aided photogrammetry
Detailed and accurate historical data are crucial to characterizing landscape change, whether it is caused by natural phenomena or of anthropogenic origin. Aerial imagery has been periodically collected by government and nongovernment agencies, for a broad range of purposes, since the early 20th century. The acquisition of aerial images involves using standardized equipment with large...
Authors
Jessica D. DeWitt, Kathleen M. Boston, Sindhuja Sunder, Sandra Bond, Pete G. Chirico, Jennifer A. Curtis, Tom Nobles, Neffra Matthews
Cambrian and Ordovician stratigraphy, conodont biostratigraphy, and microfacies analysis to support 1:24,000-scale geologic mapping of the southern Lake Champlain valley, New York and Vermont Cambrian and Ordovician stratigraphy, conodont biostratigraphy, and microfacies analysis to support 1:24,000-scale geologic mapping of the southern Lake Champlain valley, New York and Vermont
Authors
Randall C. Orndorff, Mercer Parker, Stephen A. Leslie, John E. Repetski, John T. Haynes
Stratigraphic notes—Volume 3, 2026 Stratigraphic notes—Volume 3, 2026
This is the third volume in the U.S. Geological Survey (USGS) series of reports on stratigraphy entitled “Stratigraphic Notes,” which consists of short papers that highlight stratigraphic studies, changes in stratigraphic nomenclature, and explanations of stratigraphic names and concepts used on published geologic maps. “Stratigraphic Notes” is a long-term (multiyear), multivolume...
Correcting a systematic bias in an ocean drilling project site 882 alkenone sea surface temperature record Correcting a systematic bias in an ocean drilling project site 882 alkenone sea surface temperature record
Reconstructions of sea surface temperature (SST) in the geologic record are fundamental to our understanding of Earth's climate history and the evaluation of Earth's climate sensitivity to greenhouse gas forcing. SSTs are reconstructed with a variety of methods, including alkenone biomarker lipids produced by certain coccolithophore algae. One such alkenone SST reconstruction from the...
Authors
Joseph B. Novak, Rocio P. Caballero-Gill, Timothy D. Herbert, Harry J. Dowsett, Alfredo Martinez-Garcia
Pliocene (Piacenzian) planktic foraminiferal biogeography: Insights into how planktic biogeography is linked to climate and socioeconomic impacts on marine ecosystems Pliocene (Piacenzian) planktic foraminiferal biogeography: Insights into how planktic biogeography is linked to climate and socioeconomic impacts on marine ecosystems
The Piacenzian Age (3.60–2.58 Ma) of the Pliocene Epoch was characterized by globally warmer climates, higher sea levels, and atmospheric CO2 similar to present. Utilizing a robust dataset of 2,101 samples and over 637,000 foraminifer specimens from 77 deep-sea core sites worldwide, we document planktic foraminifer biogeography and biodiversity during the mid-Piacenzian Warm Period (mPWP...
Authors
Harry J. Dowsett, Whittney Spivey, Kevin M. Foley, Marci M. Robinson
Evidence for a biological origin of uranium-rich carbon masses within the Ediacaran Salt Range Formation of Pakistan Evidence for a biological origin of uranium-rich carbon masses within the Ediacaran Salt Range Formation of Pakistan
Thucholites are unique organic structures found in igneous and sedimentary rocks composed of a U-C-rich interior enclosed by an organic outer shell. Their formation and occurrence have perplexed scientists for over 100 years. Typically, thucholites are sparse in sedimentary rocks but where found in abundance, they may be the result of rapid paleoecological disruptions, e.g., volcanic...
Authors
Brett Valentine, Paul C. Hackley, Martha Stokes, Maitrayee Bose, Ryan J. McAleer, Imran Khan
Petrography and mineralogy of selected pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida Petrography and mineralogy of selected pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida
Florida is covered by flat-lying sedimentary strata of the Atlantic and Gulf Coastal Plains. These strata have accumulated since Middle Jurassic time. The pre-Middle Jurassic, or basement, rocks that underlie the Coastal Plain in Florida are known only from drill cores and cuttings recovered from a relatively small number of boreholes. This data report presents petrographic observations...
Authors
Ryan T. Deasy, Mary E. Lupo, Ryan J. McAleer, J. Wright Horton,
Paleocene-Eocene dinoflagellate biostratigraphy in the central Delaware coastal plain Paleocene-Eocene dinoflagellate biostratigraphy in the central Delaware coastal plain
Dinoflagellate cyst palynology and lithostratigraphy from three continuously cored boreholes (Blackbird, Smyrna, and Woodland Beach), supplemented by calcareous nannofossil biostratigraphic data, were used to refine the age and correlation of three Paleocene-Eocene formations in northern Delaware: the Vincentown, Manasquan, and Shark River. Lithologic logs reveal significant facies...
Authors
Kristina Frank Gardner, Peter P. McLaughlin
Monazite and xenotime U-Pb geochronology and thermometry of the Blue Ridge and Inner Piedmont of North Carolina: Implications for the thermal-metamorphic evolution of the southern Appalachian metamorphic “core” Monazite and xenotime U-Pb geochronology and thermometry of the Blue Ridge and Inner Piedmont of North Carolina: Implications for the thermal-metamorphic evolution of the southern Appalachian metamorphic “core”
The southern Appalachian orogen preserves a complex distribution of metamorphism and deformation varying in timing, magnitude, and spatial extent. These complexities give rise to disparate interpretations for southern Appalachian tectonic evolution, which complicates the testing and interpretation of tectonic models in this system. New monazite (Mnz) and xenotime (Xtm) laser ablation...
Authors
Nicholas Edwin Powell, J. Ryan Thigpen, Brandon M. Spencer, Arthur J. Merschat, David P. Moecher, Calvin A. Mako, Robert D. Hatcher, Harold H. Stowell, Andrew R.C. Kylander-Clark
Calcareous nannofossil assemblage changes in the Surprise Hill core and their implications for floral response to the Paleocene-Eocene Thermal Maximum across the Salisbury Embayment of Virginia, USA Calcareous nannofossil assemblage changes in the Surprise Hill core and their implications for floral response to the Paleocene-Eocene Thermal Maximum across the Salisbury Embayment of Virginia, USA
We present Paleocene-Eocene calcareous nannofossil biostratigraphy and paleoecology for the Surprise Hill core, U.S. Atlantic Coastal Plain, Virginia. Calcareous nannofossil datums ranging from Zone NP3 to NP14 were identified. The Danian-aged Brightseat Formation rests unconformably atop the Lower Cretaceous Potomac Group at 211.4 m and disconformably underlies the Aquia Formation at...
Authors
Masayuki Utsunomiya, Jean Self-Trail, D. Clay Kelly, Xiaodong Zhang, Kristina Frank Gardner, James C. Zachos
Preliminary geologic map of the Sparta East, Sparta West, and parts of the Glade Valley and Whitehead 7.5-minute quadrangles, North Carolina and Virginia, and the epicentral area of the August 9, 2020, Mw 5.1 earthquake near Sparta, North Carolina Preliminary geologic map of the Sparta East, Sparta West, and parts of the Glade Valley and Whitehead 7.5-minute quadrangles, North Carolina and Virginia, and the epicentral area of the August 9, 2020, Mw 5.1 earthquake near Sparta, North Carolina
Authors
Arthur J. Merschat, Mark W. Carter, Ashley S. Lynn, Benjamin R. Weinmann, William E. Odom, Ryan J. McAleer, Shannon A. Mahan, Kevin G. Stewart, Christopher S. Holm-Denoma, E. Allen Crider,