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Melt surges, flow differentiation, and remobilization of crystal-rich mushes in response to unloading: Observations from Kīlauea Iki lava lake, Hawaii Melt surges, flow differentiation, and remobilization of crystal-rich mushes in response to unloading: Observations from Kīlauea Iki lava lake, Hawaii

Field and laboratory studies of the 1959 Kīlauea Iki lava lake have provided insight into differentiation processes in mafic magma chambers. This paper explores how partially molten basaltic mushes responded to unloading as a consequence of drilling. Most holes drilled from 1967 to 1979 terminated in a melt-rich internal differentiate with a sharp crust-melt interface. These interfaces...
Authors
Rosalind L. Helz

Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum

The Paleocene-Eocene Thermal Maximum (PETM) is recognized by a major negative carbon isotope (δ13C) excursion (CIE) signifying an injection of isotopically light carbon into exogenic reservoirs, the mass, source, and tempo of which continue to be debated. Evidence of a transient precursor carbon release(s) has been identified in a few localities, although it remains equivocal whether...
Authors
Tali L. Babila, Don E Penman, CD Standish, Monica Doubrawa, Tim J Bralower, Marci M. Robinson, Jean Self-Trail, Robert P. Speijer, Peter Stassen, Gavin L Foster, James C. Zachos

Past terrestrial hydroclimate sensitivity controlled by Earth system feedbacks Past terrestrial hydroclimate sensitivity controlled by Earth system feedbacks

Despite tectonic conditions and atmospheric CO2 levels (pCO2) similar to those of present-day, geological reconstructions from the mid-Pliocene (3.3-3.0 Ma) document high lake levels in the Sahel and mesic conditions in subtropical Eurasia, suggesting drastic reorganizations of subtropical terrestrial hydroclimate during this interval. Here, using a compilation of proxy data and multi...
Authors
R. Feng, T. Bhattacharya, B. Otto-Bliesner, E. Brady, A. M. Haywood, J. Tindall, S. J. Hunter, A. Abe- Ouchi, W.-L. Chan, M. Kageyama, C. Contoux, C. Guo, X. Li, G. Lohmann, C. Stepanek, N. Tan, Q. Zhang, Z. Zhang, Z. Han, J.R. Williams, D. J. Lunt, Harry J. Dowsett, Deepak Chandan, W. Richard Peltier

Preliminary geologic map of the Cherry Hill quadrangle, Dinwiddie, Sussex, and Greensville Counties, Virginia Preliminary geologic map of the Cherry Hill quadrangle, Dinwiddie, Sussex, and Greensville Counties, Virginia

The Cherry Hill 7.5-minute quadrangle straddles the Coastal Plain and Piedmont Provinces along the Tidewater Fall Line. Rocks of the eastern Piedmont Roanoke Rapids terrane crop out in the western part of the quadrangle and consist of greenschist- to amphibolite-facies Neoproterozoic felsic to intermediate metavolcanic rocks, some of which contain flattened quartz phenocrysts and are...
Authors
Mark W. Carter, Adam T. Karst, C. Rick Berquist, J. Stephen Schindler, Robert E. Weems, Benjamin R. Weinmann, E. Allen Crider

The Anthropocene as an event, not an epoch The Anthropocene as an event, not an epoch

Over the course of the last decade the concept of the Anthropocene has become widely established within and beyond the geoscientific literature but its boundaries remain undefined. Formal definition of the Anthropocene as a chronostratigraphical series and geochronological epoch following the Holocene, at a fixed horizon and with a precise global start date, has been proposed, but fails...
Authors
Philip Gibbard, Michael J.C. Walker, Andrew M Bauer, Matthew Edgeworth, Lucy E. Edwards, Erle C. Ellis, Stanley C. Finney, Jacqueline L Gill, Mark Maslin, Dorothy Merritts, William F Ruddiman

Shallow faulting and folding in the epicentral area of the 1886 Charleston, South Carolina, earthquake 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...
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 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)...
Authors
Paul McLaughlin, Richard Alexander, Joel Blomquist, Olivia H. Devereux, Gregory E. Noe, Tyler Wagner, Kelly L. Smalling

Geology & mineralogy of the Old Mine Park area Trumbull Connecticut 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...
Authors
Harold Moritz, Robert P. Wintsch, Bill Devlin, Ryan J. McAleer, Shinae Lee, SookJu Kim, Keewook Yi

An apparent dip calculator for spreadsheets 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...
Authors
Gregory J. Walsh

Lessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA 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...
Authors
Kristina G. Hopkins, Sean Woznicki, Brianna Williams, Charles C. Stillwell, Eric Naibert, Marina J. Metes, Daniel K. 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 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...
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) Implementation plan of the National Cooperative Geologic Mapping Program strategy—Great Lakes (Central Lowland and Superior Upland Physiographic Provinces)

Introduction The 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...
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
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