title: Mercury anomalies and the timing of biotic recovery following the end-Triassic mass extinction.
abstract: The end-Triassic mass extinction overlapped with the eruption of the Central Atlantic Magmatic Province (CAMP), and release of CO2 and other volcanic volatiles has been implicated in the extinction. However, the timing of marine biotic recovery versus CAMP eruptions remains uncertain. Here we use Hg concentrations and isotopes as indicators of CAMP volcanism in continental shelf sediments, the primary archive of faunal data. In Triassic-Jurassic strata, Muller Canyon, Nevada, Hg levels rise in the extinction interval, peak before the appearance of the first Jurassic ammonite, remain above background in association with a depauperate fauna, and fall to pre-extinction levels during significant pelagic and benthic faunal recovery. Hg isotopes display no significant mass independent fractionation within the extinction and depauperate intervals, consistent with a volcanic origin for the Hg. The Hg and palaeontological evidence from the same archive indicate that significant biotic recovery did not begin until CAMP eruptions ceased.
authors.affiliation: Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada.|Department of Earth Sciences, Dickinson College, Carlisle, Pennsylvania 17013, USA.
authors.forename: Alyson M
authors.initials: AM
authors.lastname: Thibodeau
authors.affiliation: Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84103, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Ritterbush
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Joyce A
authors.initials: JA
authors.lastname: Yager
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: A Joshua
authors.initials: AJ
authors.lastname: West
authors.affiliation: Department of Earth System Science, Stanford University, Stanford, California 94305, USA.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Ibarra
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Bottjer
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Berelson
authors.affiliation: Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada.
authors.forename: Bridget A
authors.initials: BA
authors.lastname: Bergquist
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Corsetti
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002245:Carbon Dioxide / Q000737:chemistry*; D002247:Carbon Isotopes; D053476:Extinction, Biological; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D008629:Mercury Isotopes; D009505:Nevada; D018707:Volcanic Eruptions / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D008629:Mercury Isotopes; D002245:Carbon Dioxide; D008628:Mercury