Associate Professor
Disciplines:
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Research Affiliation:
Lamont-Doherty Earth Observatory
413 Comer
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8417
Fields of interest:
geochronology, sedimentary geochemistry, paleoclimate, continental crust evolution Understanding the provenance and processes recorded in the geochemistry of sediments and sedimentary rocks lies at the heart of my research interests. I am also interested in geochronological studies. I have a strong interest in the tectonics and continental crust evolution questions on the longer time scale. I have an active program of applying radiogenic isotopes for tracing the sources of sediments with the goal of understanding Quaternary climate changes and associated changes in winds, currents and glaciers. Provenance studies of ice rafted detritus are key to working out the dynamic relationships among paleo-climate and paleo-ocean circulation and their interactions with the large ice sheets that covered the northern continents during the ice ages. Isotopic tracers are also important to understand other aspects of paleo-climate and paleoceanography. Nd and Pb isotope compositions of the authigenic Mn-Fe precipitates in marine sediments may be used to evaluate past changes in circulation of the deep ocean. Isotope tracers of the terrigenous clay fraction can be used to evaluate past changes in sediment sources and current paths.
Educational Activities: Lamont Projects: Selected Publications: Paleoclimate - Climate swings come into focus, , Science, Dec 14, Volume 294, Issue 5550, p.2308-2309, (2001) Laschamp excursion at Mono Lake?, , Earth and Planetary Science Letters, Apr 15, Volume 197, Issue 3-4, p.151-164, (2002), Pii S0012-821x(02)00474-0 Ar-40/Ar-39 ages and Ar-40* concentrations of fine-grained sediment fractions from North Atlantic Heinrich layers, , Chemical Geology, Feb 15, Volume 182, Issue 2-4, p.583-603, (2002), Pii S0009-2541(01)00342-4 Radiogenic isotopes as tracers of sediment provenance and flux: Paleoceanography of the South Atlantic, , Geochimica Et Cosmochimica Acta, Sep, Volume 67, Issue 18, p.A102-A102, (2003) Heinrich events: Massive late pleistocene detritus layers of the North Atlantic and their global climate imprint, , Reviews of Geophysics, Mar 18, Volume 42, Issue 1, p.-, (2004), Doi 10.1029/2003rg000128 Ar-40/Ar-39 ages of hornblende grains and bulk Sm/Nd isotopes of circum-Antarctic glacio-marine sediments: Implications for sediment provenance in the Southern Ocean, , Chemical Geology, Oct 15, Volume 244, Issue 3-4, p.507-519, (2007), DOI 10.1016/j.chemgeo.2007.07.017 Modeling the marine nd isotope variability with an offline ocean general circulation model, , Geochimica Et Cosmochimica Acta, Jul, Volume 72, Issue 12, p.A439-A439, (2008) Spectral analysis of the lower Eocene Wilkins Peak Member, Green River Formation, Wyoming: Support for Milankovitch cyclicity, , Earth and Planetary Science Letters, Apr 15, Volume 268, Issue 1-2, p.64-75, (2008), DOI 10.1016/j.epsl.2007.12.024 Contrasting compositions of Saharan dust in the eastern Atlantic Ocean during the last deglaciation and African Humid Period, , Earth and Planetary Science Letters, Volume 278, Issue 3-4, p.257-266, (2009), doi:10.1016/j.epsl.2008.12.011 |
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