Daniel H Doctor
Dan is a research geologist conducting geologic mapping and specialized geologic research for the Appalachian Basin project. His current research interests include stratigraphy of the Appalachian Basin, landscape evolution within the Appalachian Valley and Ridge physiographic province, karst hydrology and geomorphology, sinkhole hazard studies, and paleoclimate records from karst regions.
Biography
Dan began a career with the USGS in 2002 as an NRC postdoc within the Isotope Tracers of Biogeochemical and Hydrologic Processes project of the National Research Program in Menlo Park, California. In 2006, he joined the Florence Bascom Geoscience Center in Reston, Virginia.
Education:
Ph.D. (2002) in Hydrogeology/Geochemistry, with Doctoral Minor in Water Resources Science, University of Minnesota, Dept. of Geology and Geophysics, Minneapolis, MN
Dissertation title: The Hydrogeology of the Classical Karst (Kras) Aquifer of Southwestern Slovenia
Bachelor of Arts (1994) in Geology, Minor in Environmental Studies
Colgate University, Hamilton, NY (Magna Cum Laude, Phi Beta Kappa)
Professional Experience:
Research Geologist (2006-present). U.S. Geological Survey, KARST Project, Eastern Geology and Paleoclimate Science Center, Reston, VA
Hydrologist (2004-2006). U.S. Geological Survey, Isotope Tracers Group, Water Resources Division, Menlo Park, CA
Postdoctoral Research Associate, National Research Council (NRC) (2002-2004). U.S. Geological Survey, Isotope Tracers Group, Water Resources Division, Menlo Park, CA
Project Analyst (2001). Lands and Minerals Division, Minnesota Department of Natural Resources (MN-DNR).
Science and Products
Appalachian Basin Geologic Mapping Project
The Appalachian Basin Geologic Mapping Project performs geologic mapping at local and regional scales, and geologic research in The Valley and Ridge and Appalachian Plateaus physiographic provinces. These provinces include parts of 11 states and mainly borders the Blue Ridge / Piedmont and North Interior Lowlands Provinces. Two states have Valley and Ridge geology only (GA, NJ), two have...
Subsidence Susceptibility Map for the Conterminous U.S.
Sinkholes present hazards to humans due to subsidence and by focusing contaminated surface water runoff into groundwater. Sinkholes create instability in the foundations of buildings, roads and other infrastructure, resulting in damage and in some cases loss of life, but may also play an important role as vernal pools in some ecosystems. This project created a prototype nationwide subsidence...
Appalachian Basin stratigraphy, tectonics, and eustasy from the Blue Ridge to the Allegheny Front, Virginia and West Virginia
This guide is from a two-day field trip in western Virginia and eastern West Virginia held before the 2015 Geological Society of America annual meeting in Baltimore, Maryland. The field trip examines exposures of Paleozoic sedimentary strata in the Appalachian Basin starting in the Blue Ridge physiographic province, going through the Valley and...
Haynes, John T.; Pitts, Alan D.; Doctor, Daniel H.; Diecchio, Richard J.; Blake, Mitchell B.
Geologic map of the Hayfield quadrangle, Frederick County, Virginia
The Hayfield 7.5-minute quadrangle is located within the Valley and Ridge physiographic province of northern Virginia. The quadrangle includes the topographical lowland area of the northern Great Valley to the southeast, the narrow ridge of Little North Mountain along the western edge of the Great Valley, and the broad region of elongated valleys...
Doctor, Daniel H.; Parker, Ronald A. Hypogene caves of the central Appalachian Shenandoah Valley in Virginia
Several caves in the Shenandoah Valley in Virginia show evidence for early hypogenic conduit development with later-enhanced solution under partly confined phreatic conditions guided by geologic structures. Many (but not all) of these caves have been subsequently invaded by surface waters as a result of erosion and exhumation. Those not so...
Doctor, Daniel H.; Orndorff, Wil New insight into the origin of manganese oxide ore deposits in the Appalachian Valley and Ridge of northeastern Tennessee and northern Virginia, USA
Manganese oxide deposits have long been observed in association with carbonates within the Appalachian Mountains, but their origin has remained enigmatic for well over a century. Ore deposits of Mn oxides from several productive sites located in eastern Tennessee and northern Virginia display morphologies that include botryoidal and branching...
Carmichael, Sarah K.; Doctor, Daniel H.; Wilson, Crystal G.; Feierstein, Joshua; McAleer, Ryan J. Book review: Karst without boundaries
No abstract available.
Doctor, Daniel H. Predicting the occurrence of cave-inhabiting fauna based on features of the earth surface environment
One of the most challenging fauna to study in situ is the obligate cave fauna because of the difficulty of sampling. Cave-limited species display patchy and restricted distributions, but it is often unclear whether the observed distribution is a sampling artifact or a true restriction in range. Further, the drivers of the distribution could be...
Christman, Mary C.; Doctor, Daniel H.; Niemiller, Matthew L.; Weary, David J.; Young, John A.; Zigler, Kirk S.; Culver, David C. Analysis of hydrologic and geochemical time-series data at James Cave, Virginia: Implications for epikarst influence on recharge in Appalachian karst aquifers
The epikarst, which consists of highly weathered rock in the upper vadose zone of exposed karst systems, plays a critical role in determining the hydrologic and geochemical characteristics of recharge to an underlying karst aquifer. This study utilized time series (2007–2014) of hydrologic and geochemical data of drip water collected within...
Eagle, Sarah D.; Orndorff, William; Schwartz, Benjamin F.; Doctor, Daniel H.; Gerst, Jonathan D.; Schreiber, Madeline E. A semi-automated tool for reducing the creation of false closed depressions from a filled LIDAR-derived digital elevation model
Closed depressions on the land surface can be identified by ‘filling’ a digital elevation model (DEM) and subtracting the filled model from the original DEM. However, automated methods suffer from artificial ‘dams’ where surface streams cross under bridges and through culverts. Removal of these false depressions from an elevation model is...
Wall, John; Doctor, Daniel H.; Terziotti, Silvia Hydrologic and geochemical dynamics of vadose zone recharge in a mantled karst aquifer: Results of monitoring drip waters in Mystery Cave, Minnesota
Caves provide direct access to flows through the vadose zone that recharge karst aquifers. Although many recent studies have documented the highly dynamic processes associated with vadose zone flows in karst settings, few have been conducted in mantled karst settings, such as that of southeastern Minnesota. Here we present some results of a long-...
Doctor, Daniel H.; Alexander, E. Calvin; Jameson, Roy A.; Alexander, Scott C. Karst of the Mid-Atlantic region in Maryland, West Virginia, and Virginia
The Mid-Atlantic region hosts some of the most mature karst landscapes in North America, developed in highly deformed rocks within the Piedmont and Valley and Ridge physiographic provinces. This guide describes a three-day excursion to examine karst development in various carbonate rocks by following Interstate 70 west from Baltimore across the...
Brezinski, David K.; Halka, Jeffrey; Ortt, Richard A.; Doctor, Daniel H.; Weary, David J.; Brezinski, David K.; Orndorff, Randall C.; Spangler, Lawrence E. Karst mapping in the United States: Past, present and future
The earliest known comprehensive karst map of the entire USA was published by Stringfield and LeGrand (1969), based on compilations of William E. Davies of the U.S. Geological Survey (USGS). Various versions of essentially the same map have been published since. The USGS recently published new digital maps and databases depicting the extent of...
Weary, David J.; Doctor, Daniel H. Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia
Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave,...
Schreiber, Madeline E.; Schwartz, Benjamin F.; Orndorff, William; Doctor, Daniel H.; Eagle, Sarah D.; Gerst, Jonathan D.