title: Geochemistry. In mass extinction, timing is all.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kerr
mesh_terms: D000818:Animals; D002681:China; D005580:Fossils; D019015:Geologic Sediments; D005844:Geology / Q000379:methods*; D007554:Isotopes / Q000032:analysis; D007854:Lead / Q000032:analysis; D011156:Population Density; D011157:Population Dynamics; D017640:Silicates / Q000737:chemistry; D013995:Time; D014501:Uranium / Q000032:analysis; D018707:Volcanic Eruptions; D015040:Zirconium / Q000737:chemistry
chemical_list: D007554:Isotopes; D017640:Silicates; D007854:Lead; D014501:Uranium; C003784:zircon; D015040:Zirconium