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Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired watersheds and estuaries around the world, and this syn
Authors
Gregory B. Noe, Matt J. Cashman, Katherine Skalak, Allen C. Gellis, Kristina G. Hopkins, Doug L. Moyer, James S. Webber, Adam Benthem, Kelly O. Maloney, John Brakebill, Andrew Sekellick, Michael J. Langland, Qian Zhang, Gary W. Shenk, Jennifer L. D. Keisman, Cliff R. Hupp

Progress toward a preliminary karst depression density map for the conterminous United States

Most methods for the assessment of sinkhole hazard susceptibility are predicated upon knowledge of pre-existing closed depressions in karst areas. In the United States (U.S.), inventories of existing karst depressions are piecemeal, and are often obtained through inconsistent methodologies applied at the state or county level and at various scales. Here, we present a first attempt at defining a ka
Authors
Daniel H. Doctor, Jeanne M. Jones, Nathan J. Wood, Jeff T. Falgout, Natalya Igorevna Rapstine

Evaluating elevation change thresholds between structure-from-motion DEMs derived from historical aerial photos and 3DEP LiDAR data

This study created digital terrain models (DTMs) from historical aerial images using Structure from Motion (SfM) for a variety of image dates, resolutions, and photo scales. Accuracy assessments were performed on the SfM DTMs, and they were compared to the United States Geological Survey’s three-dimensional digital elevation program (3DEP) light detection and ranging (LiDAR) DTMs to evaluate geomo
Authors
Peter G. Chirico, Jessica D. DeWitt, Sarah E. Bergstresser

North American Commission on Stratigraphic Nomenclature Note 70: Records of the Stratigraphic Commission 2014-2017

NACSN (North American Commission on Stratigraphic Nomenclature) Note 70 is a summary of the activities of the Commission from October 2014-October 2017. This note is condensed from the minutes of the 69th through the 72nd meetings of the NACSN held in conjunction with the Annual Meetings of the Geological Society of America. The 69th meeting of the NACSN was held October 20, 2014, in Vancouver, Br
Authors
Richard H. Fluegeman, Carlton E. Brett, Frank Brunton, Lucy E. Edwards, Howard Harper

Geomorphological mapping and anthropogenic landform change in an urbanizing watershed using structure-from-motion photogrammetry and geospatial modeling techniques

Increasing urbanization and suburban growth in cities globally has highlighted the importance of land planning using detailed geomorphologic maps that depict anthropogenic landform changes. Such mapping provides information crucial for land management, hazard identification, and the management of the challenges arising from urbanization. The development and use of quantitative and repeatable metho

40Ar/39Ar and U-Pb SIMS zircon ages of Ediacaran dikes from the Arabian-Nubian Shield of south Jordan

A spectacular feature of the Arabian-Nubian Shield (ANS) is the abundance of well-exposed and extensive Neoproterozoic dike swarms of multiple generations. These dikes are generally categorized into metamorphosed and unmetamorphosed post-orogenic dike swarms. The unmetamorphosed dikes in the northern ANS can be grouped into an old and young generations. We dated three dikes from the old generation

Authors
Hind Ghanem, Ryan J. McAleer, Ghaleb Jarrar, Mu'ayyad Al Hseinat, Martin Whitehouse

Geology of the Trout Rock caves (Hamilton Cave, Trout Cave, New Trout Cave) in Pendleton County, West Virginia (USA), and implications regarding the origin of maze caves

The Trout Rock caves (Hamilton Cave, Trout Cave, New Trout Cave) are located in a hill named Cave Knob that overlooks the South Branch of the Potomac River in Pendleton County, West Virginia (U.S.A). The geologic structure of this hill is a northeasttrending anticline, and the caves are located at different elevations primarily along the contact between the Devonian New Creek Limestone (Helderberg
Authors
Christopher S. Swezey, Emily L Brent

Foreward: Geology Field Trips in and around the U.S. Capital

The first annual meeting of the Geological Society of America (GSA) was held in 1888 in Ithaca, New York (Fairchild, 1932), but official Sections of GSA formed much later. During the spring of 1949, a symposium in Knoxville, Tennessee, on mineral resources of the southeastern United States became the catalyst for the creation of the Southeastern Section of the Geological Society of America (King,
Authors
Christopher S. Swezey, Mark W. Carter

Geochronologic age constraints on tectonostratigraphic units of the central Virginia Piedmont, USA

New geologic mapping coupled with uranium-lead (U-Pb) zircon geochronology (sensitive high-resolution ion microprobe-reverse geometry [SHRIMP-RG] and laser ablation-inductively coupled plasma-mass spectrometry [LA-ICP-MS]) analyses of 10 samples, provides new constraints on the tectonostratigraphic framework of the central Virginia Piedmont. Detrital zircon analysis confirms that the Silurian-Devo

Authors
Mark W. Carter, Ryan J. McAleer, Christopher S. Holm-Denoma, David B. Spears, Sean P. Regan, William C. Burton, Nick H. Evans

Carbon release through abrupt permafrost thaw

The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in
Authors
Merritt R. Turetsky, Benjamin W. Abbott, Miriam C. Jones, Katey Walter Anthony, David Olefeldt, Edward A. Schuur, Guido Grosse, Peter Kuhry, Gustaf Hugelius, Charles Koven, David M. Lawrence, Carolyn Gibson, A. Britta K. Sannel, A.D. McGuire

Estimating late 19th century hydrology in the Greater Everglades Ecosystem: An integration of paleoecologic data and models

Determining hydrologic conditions prior to instrumental records is a challenge for restoration of freshwater ecosystems worldwide. Paleoecologic data provide this information on past conditions and when these data are used to adjust hydrologic models, allow conditions to be hindcast that may not be directly estimated from the paleo-data alone. In this context, the paleo-data provide real-world es
Authors
Frank E. Marshall, Christopher E. Bernhardt, G. Lynn Wingard

Marine latitudinal diversity gradients, niche conservatism and out of the tropics and Arctic: Climatic sensitivity of small organisms

AimThe latitudinal diversity gradient (LDG) is a consequence of evolutionary and ecological mechanisms acting over long history, and thus is best investigated with organisms that have rich fossil records. However, combined neontological‐palaeontological investigations are mostly limited to large, shelled invertebrates, which keeps our mechanistic understanding of LDGs in its infancy. This paper ai
Authors
Wing‐Tung Ruby Chiu, Moriaki Yasuhara, Thomas M. Cronin, Gene Hunt, Laura Gemery, Chih‐Lin Wei