The measurement of cosmogenic radionuclides 10Be and 26Al by accelerator mass spectrometry (AMS) has become an invaluable tool for dating events processes in Quaternary geochronology, archaeology paleoanthropology. Here we present overview the current state research providing theoretical methodological background describe sample preparation AMS. We also summarize main geochronology calculation ...

Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; Berkeley Geochronology Center, Berkeley, CA 94709; Department of Earth and Planetary Science, University of California, Berkeley, CA 94720; Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 10024; and Centre Européen de Recherche et d’E...

The chemistry and isotope chemistry of natural materials is highly indicative of provenance and process throughout geological history. Our studies range in time from the earliest solar system through to processes that are actively taking place today, and in scope from planetary systems to individual molecules. Active areas of research centre on planetary studies, metamorphic and igneous geochem...

Zircon (ZrSiO4) is the most commonly used geochronometer, preserving age and geochemical information through a wide range of geological processes. However, zircon U-Pb geochronology can be affected by redistribution of radiogenic Pb, which is incompatible in the crystal structure. This phenomenon is particularly common in zircon that has experienced ultra-high temperature metamorphism, where io...

ht://ad D ow nladed fom Quantitative constraints on the ages of melt-forming impact events on the Moon are based primarily on isotope geochronology of returned samples. However, interpreting the results of such studies can often be difficult because the provenance region of any sample returned from the lunar surface may have experienced multiple impact events over the course of billions of year...

The Stirling Range Formation in southwestern Australia contains discoidal fossils previously linked to the late Neoproterozoic Ediacaran biota and possible trace fossils interpreted to have been made by vermiform, mucus-producing, motile organisms. The age of the sedimentary succession was recently reported to be between 2.0 and 1.2 billion years old, based on U–Pb geochronology of detrital zir...

U–Pb zircon geochronology is hampered by problems acquiring meaningful geologic ages on zoned grains that retain isotope signatures from multiple growth or thermal events. We present a new method using laser ablation-multicollector-inductively coupled plasma-mass spectrometry to overcome complications asso­ ciated with intricately zoned zircon crystals through in situ sampling of zircon volumes...

The past 15 years have produced numerous innovations in geochronology, including experimental methods, instrumentation, and software that are revolutionizing the acquisition and application of geochronological data. For example, exciting advances are being driven by Laser-Ablation ICP Mass Spectrometry (LA-ICPMS), which allows for rapid determination of U-Th-Pb ages with 10s of micrometer-scale...

Floodplain sedimentation removes particles from fluvial transport and constructs stratigraphic records of flooding, biogeochemical sequestration and other aspects of the environmental history of river basins-insight that is enhanced by accurate geochronology. The natural fallout radionuclide (210)Pb, often employed to date lacustrine and marine sediments, has previously been used to determine f...