Two years of funding supports an ongoing interdisciplinary program to calibrate North American non-marine fossil-bearing sedimentary rocks and associated magnetostratigraphies through extensive application of high precision SCLF (Single Crystal Laser Fusion) 40Ar/39Ar and conventional 40K-40Ar dating. PIs will collect,k prepare and date volcanic rocks associated with magnetostratigraphies developed or currently being developed on non-marine strata of Lancian-Puercan (Cretaceous-Tertiary), Clarkforkian (L. Paleocene-E. Eocene), and Chadronian through Hemjingfordian (L. Eocene-Oligocene-E. Miocene) ages. The results obtained over the past year and the projected results of this study will provide precise and accurate calibration points for the numerical age calibration of North American fossil faunas, floras and associated lmagnetostratigraphies. The high resolution ages will serve as a basis for 1) the calibration North American Land Mammal "Ages" and their subdivisions, 2) the correlation of NALMAs to standard European stage/ages, 3) the calibration of the MPTS (Magnetic Polarity Time Scale), 4) an independent chronology for determining rates of morphologic evolution in fossil vertebrates and plants and 5) the interpretation of the temporal histories of sedimentary basins of western North America, including sedimentation, subsidence and uplift rates.
