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Shallow faulting and folding in the epicentral area of the 1886 Charleston, South Carolina, earthquake

The moment magnitude (⁠Mw�w⁠) ∼7 earthquake that struck Charleston, South Carolina, on 31 August 1886 is the largest historical earthquake in the United States east of the Appalachian Mountains. The fault(s) that ruptured during this earthquake has never been conclusively identified, and conflicting fault models have been proposed. Here we interpret reprocessed seismic reflection profiles, reproce
Authors
Thomas L. Pratt, Anjana K. Shah, R.C Counts, J. Wright Horton,, M.C. Chapman

Power analysis for detecting the effects of best management practices on reducing nitrogen and phosphorus fluxes to the Chesapeake Bay watershed, USA

In 2010 the U.S. Environmental Protection Agency established the Total Maximum Daily Load (TMDL) which is a “pollution diet” that aims to reduce the amount of nitrogen and phosphorus entering the Chesapeake Bay, the largest estuary in the United States, by 25 and 24% percent, respectively. To achieve this goal the TMDL requires the implementation of Best Management Practices (BMPs), which are acce
Authors
Paul McLaughlin, Richard Alexander, Joel Blomquist, Olivia H. Devereux, Gregory B. Noe, Kelly L. Smalling, Tyler Wagner

Geology & mineralogy of the Old Mine Park area Trumbull Connecticut

Old Mine Park, in the northern Trumbull area (also known as Long Hill) of southwestern Connecticut, is a recreation area encompassing the mineral-rich hill of “Saganawamps” and owned by the Town of Trumbull. Most of its 72 acres are wooded, rocky and undeveloped but it is surrounded by dense infrastructure and transportation, residential, retail, and commercial development (Figure 1). It preserves
Authors
Harold Moritz, Robert P. Wintsch, Bill Devlin, Ryan J. McAleer, Shinae Lee, SookJu Kim, Keewook Yi

An apparent dip calculator for spreadsheets

This report and spreadsheet calculator contain Microsoft Excel-based equations that are useful in structural geology to calculate plunge or apparent dip when measuring lineations on a plane. The spreadsheet allows users to measure the trend or the plunge of a lineation and calculate the corresponding unknown value of trend or plunge. The spreadsheet provides the user with two options:Option 1: Cal
Authors
Gregory J. Walsh

Lessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA

Urban development is a well-known stressor for stream ecosystems, presenting a challenge to managers tasked with mitigating its effects. For the past 20 y, streamflow, water quality, geomorphology, and benthic communities were monitored in 5 watersheds in Montgomery County, Maryland, USA. This study presents a synthesis of multiple studies of monitoring efforts in the study area and new analysis o
Authors
Kristina G. Hopkins, Sean Woznicki, Brianna Williams, Charles C. Stillwell, Eric Naibert, Marina Metes, Daniel Jones, Dianna M. Hogan, Natalie Celeste Hall, Rosemary M. Fanelli, Aditi S. Bhaskar

A comparison of orbital-resolution, Late Pleistocene Alkenone and foraminiferal assemblage-based sea surface temperature reconstructions from the Southwest Pacific

Global and regional reconstructions of past climate conditions often incorporate sea surface temperature (SST) estimates from multiple proxies because not every paleotemperature proxy is applicable in all geographic locations. This practice of assimilating estimates from different proxies in global or regional temperature syntheses makes the implicit assumption that estimates derived from differen
Authors
Emilie A. Henry, Kira T. Lawrence, Laura C. Peterson, Marci M. Robinson

Implementation plan of the National Cooperative Geologic Mapping Program strategy—Great Lakes (Central Lowland and Superior Upland Physiographic Provinces)

IntroductionThe U.S. Geological Survey (USGS) National Cooperative Geologic Mapping Program (NCGMP) has published a strategic plan entitled “Renewing the National Cooperative Geologic Mapping Program as the Nation’s Authoritative Source for Modern Geologic Knowledge”. This plan provides the following vision, mission, and goals for the program for the years 2020–30:Vision: create an integrated, thr
Authors
Christopher S. Swezey, Charles D. Blome, Kevin A. Kincare, Scott C. Lundstrom, Byron D. Stone, Donald S. Sweetkind, Richard C. Berg, Steven E. Brown, John A. Yellich

Regression of the Tethys Sea (central Asia) during middle to late Eocene: Evidence from calcareous nannofossils of western Tarim Basin, NW China

Calcareous nannofossil assemblages from middle to upper Eocene sediments of the western Tarim Basin indicate two important episodes of marine incursion into the basin. The first episode represents a period of shallowing upward in the Wulagen Formation, which is dated as Zone CNE13 (Lutetian) by the co-occurrence of Discoaster bifax, Chiasmolithus solitus, and common Reticulofenestra umbilicus. The
Authors
Xuejiao Wang, Dangpeng Xi, David K. Watkins, Jean Self-Trail, Zihua Tang, Wenxin Cao, Tiantian Jiang, Muhammad Kamran, Xiaoqiao Wan

Evolution and taxonomy of the Paleogene calcareous nannofossil genus Hornibrookina

The genus Hornibrookina consists of enigmatic calcareous nannofossils that first appeared shortly after the K-Pg mass extinction. Due to their relative paucity in most published sections, specimens of this genus have not been previously studied in detail and their paleobiogeographic preferences and evolutionary history have been poorly understood. Biostratigraphic and morphometric analyses of Horn
Authors
Jean Self-Trail, David K. Watkins, James J. Pospichal, Ellen Seefelt

Mapping the extent and methods of small-scale emerald mining in the Panjshir Valley, Afghanistan

Emerald mining in the Panjshir Valley, Afghanistan, has occurred for thousands of years, yet few records exist documenting the detailed spatial extent, techniques, or productivity of small-scale miners. This study proposes new methods to map and monitor the extent and changes in small-scale mining in remote and inaccessible terrain by integrating multispectral remote sensing analysis with archival
Authors
Jessica D. DeWitt, Peter G. Chirico, Kelsey L. O'Pry, Sarah E. Bergstresser

Stop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia

Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained gra
Authors
Mark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. Owens

Stratigraphy and age of a prominent paleosol in a late Pleistocene sedimentary sequence, Mason Neck, Virginia

The High Point paleosol is 2.28-meters-thick aggradational soil developed in fining upward estuarine-alluvial sand and loess. The paleosol is exposed in a few shoreline cliff faces of Mason Neck, Virginia. Although a former A horizon is missing, the E, Bw, Bt, and C horizon sequence seen in the sediments indicates subaerial pedogenesis. Pedogenesis began with initial estuarine-alluvial floodplain
Authors
Helaine W. Markewich, Douglas A. Wysocki, Milan J. Pavich, Joseph P. Smoot, Ronald J. Litwin