![]() ![]() burial and heating rocks as well as their uplift toward the surface) provide first order constraints on the processes that control the physical evolution of our planet. Understanding the timing and duration of geologic events in the deep earth (e.g. Their policies may differ from this site. Some links on this page may take you to non-federal websites. Some full text articles may not yet be available without a charge during the embargo (administrative interval). When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH The results of the proposed research will impact the geochronology community at large: o Thermal Ionization Mass Spectrometry o Secondary Ionization Mass Spectrometry o Electron Probe MicroAnalysis o (Laser Ablation) Inductively Coupled Plasma Mass Spectrometry ![]() This study will train undergraduates (UCSB) in laboratory investigations and provide a component of graduate research for graduate students at UCSB and Stanford. In addition, Peterman is a young female scientist (Ph.D. This project supports two early career scientists-John Cottle (UCSB faculty) and Emily Peterman (Stanford Postdoctoral Fellow). This module will demonstrate linking pressure, temperature and time histories. o An educational module will be developed that can be integrated into the EARTHTIME mission for educating students about understanding geologic time. This information will be linked to the EARTHTIME website. This proposed research seeks to address the fundamental aim of the EARTHTIME initiative: "the development of the geochronological techniques necessary to produce temporal constraints with uncertainties approaching 0.1 % of the radioisotopic ages." o A website will be developed that contains the information about the reference materials and the methods for measuring the ID TIMS and ICP-MS ages. o Improves precision on age measurements for a chronometer that can be directly linked to the metamorphic and magmatic history of a terrane o Provides well-characterized standards to the community for high-precision, standardbased geochronology. Intellectual Merit o Eliminates the need to assume concordance among the three decay systems (235U, 238U and 232Th decay chains) by providing independently verified U-Pb and Th-Pb ages. By obtaining high-precision ID Th-Pb ages for a suite of well-characterized, community-wide reference materials, this research will provide a means of independently calibrating Th-Pb ages for minerals that can be linked to fundamental tectonic processes. This assumption is unnecessary and, in many cases, invalid. Consequently, all standard-based geochronologic measurements require an assumption that Th-Pb and U-Pb ages are equivalent. Th-Pb ages currently exist for only one reference material that is commonly used-'554'. This proposal seeks to determine isotope dilution (ID) Th-Pb ages for the Th-rich accessory minerals monazite and allanite. Because both monazite and allanite are compositionally variable and SIMS, LA-ICP-MS incur instrumental mass-dependent fractionation, it is essential to closely match standards with unknowns. Primary Place of Performance Congressional District:Ġ1001112DB NSF RESEARCH & RELATED ACTIVIT 01001213DB NSF RESEARCH & RELATED ACTIVITĬollaborative Research: Improving the accuracy and precision ofmonazite and allanite geochronology via ID Th-Pb ages for referencematerials The principal limitation for obtaining high-precision, accurate standard-based 208Pb/232Th ages from monazite and allanite is the lack of appropriate, well-characterized reference materials. John Cottle (Principal Investigator) Sponsored Research Office:.To get the weather to display you are directed to visit this link: and get your personal API key free of charge.Collaborative Research: Improving the Accuracy and Precision of Monazite and Allanite Geochronology via ID Th-Pb Ages for Reference Materials NSF Org: ![]()
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