Nancy is part of the USGS Florence Bascom Geoscience Center. She manages the stratigraphic palynology lab and the climate change pollen lab. She specializes in the extraction of dinoflagellates and pollen from various sedimentary rock types and unconsolidated sediments
Professional Experience
Started working at USGS in 1988 as a Physical Science Technician in the Palynology lab.
Education and Certifications
Indiana University of Pennsylvania (IUP) - BS Geology
Science and Products
100,000-year-long terrestrial record of millennial-scale linkage between eastern North American mid-latitude paleovegetation shifts and Greenland ice-core oxygen isotope trends
We document frequent, rapid, strong, millennial-scale paleovegetation shifts throughout the late Pleistocene, within a 100,000+ yr interval (~ 115–15 ka) of terrestrial sediments from the mid-Atlantic Region (MAR) of North America. High-resolution analyses of fossil pollen from one core locality revealed a continuously shifting sequence of thermally dependent forest assemblages, ranging between tw
Authors
Ronald J. Litwin, Joseph P. Smoot, Milan J. Pavich, Helaine W. Markewich, George Brook, Nancy J. Durika
Analysis of the deconstruction of Dyke Marsh, George Washington Memorial Parkway, Virginia-Progression, geologic and manmade causes, and effective restoration scenarios
This report is a synthesis of the latest findings from an ongoing study of Dyke Marsh, an eroding freshwater tidal wetland that is scheduled for federal restoration. Its purpose is to provide an accurate and up-to-date temporal and geological framework for the marsh, of which most is new information (plus a compilation of historical and recent information), that is directly relevant to the restora
Authors
Ronald J. Litwin, Joseph P. Smoot, Milan J. Pavich, Helaine W. Markewich, Erik Oberg, Ben Helwig, Brent Steury, Vincent L. Santucci, Nancy J. Durika, Nancy B. Rybicki, Katharina M. Engelhardt, Geoffrey Sanders, Stacey Verardo, Andrew J. Elmore, Joseph Gilmer
Calibrating Late Quaternary terrestrial climate signals: radiometrically dated pollen evidence from the southern Sierra Nevada, USA
We constructed a radiometrically calibrated proxy record of Late Pleistocene and Holocene climate change exceeding 230,000 yr duration, using pollen profiles from two cores taken through age-equivalent dry lakes - one core having greater age control (via 230Th alpha mass-spectrometry) and the other having greater stratigraphic completeness. The better dated of these two serial pollen records (Sear
Authors
Ronald J. Litwin, Joseph P. Smoot, Nancy J. Durika, George I. Smith
Science and Products
- Publications
100,000-year-long terrestrial record of millennial-scale linkage between eastern North American mid-latitude paleovegetation shifts and Greenland ice-core oxygen isotope trends
We document frequent, rapid, strong, millennial-scale paleovegetation shifts throughout the late Pleistocene, within a 100,000+ yr interval (~ 115–15 ka) of terrestrial sediments from the mid-Atlantic Region (MAR) of North America. High-resolution analyses of fossil pollen from one core locality revealed a continuously shifting sequence of thermally dependent forest assemblages, ranging between twAuthorsRonald J. Litwin, Joseph P. Smoot, Milan J. Pavich, Helaine W. Markewich, George Brook, Nancy J. DurikaAnalysis of the deconstruction of Dyke Marsh, George Washington Memorial Parkway, Virginia-Progression, geologic and manmade causes, and effective restoration scenarios
This report is a synthesis of the latest findings from an ongoing study of Dyke Marsh, an eroding freshwater tidal wetland that is scheduled for federal restoration. Its purpose is to provide an accurate and up-to-date temporal and geological framework for the marsh, of which most is new information (plus a compilation of historical and recent information), that is directly relevant to the restoraAuthorsRonald J. Litwin, Joseph P. Smoot, Milan J. Pavich, Helaine W. Markewich, Erik Oberg, Ben Helwig, Brent Steury, Vincent L. Santucci, Nancy J. Durika, Nancy B. Rybicki, Katharina M. Engelhardt, Geoffrey Sanders, Stacey Verardo, Andrew J. Elmore, Joseph GilmerCalibrating Late Quaternary terrestrial climate signals: radiometrically dated pollen evidence from the southern Sierra Nevada, USA
We constructed a radiometrically calibrated proxy record of Late Pleistocene and Holocene climate change exceeding 230,000 yr duration, using pollen profiles from two cores taken through age-equivalent dry lakes - one core having greater age control (via 230Th alpha mass-spectrometry) and the other having greater stratigraphic completeness. The better dated of these two serial pollen records (SearAuthorsRonald J. Litwin, Joseph P. Smoot, Nancy J. Durika, George I. Smith