Siderophile interelement variations in the Cretaceous-Tertiary boundary sediments from Caravaca, Spain
1985; Elsevier BV; Volume: 73; Issue: 2-4 Linguagem: Inglês
10.1016/0012-821x(85)90067-6
ISSN1385-013X
AutoresFrank T. Kyte, Jan Smit, J. T. Wasson,
Tópico(s)Paleontology and Stratigraphy of Fossils
ResumoA detailed profile of the siderophiles Fe, Co, Ni, Pd, Re, Os, Ir, Pt, and Au from the Cretaceous-Tertiary boundary at Caravaca, Spain, indicates that the major fractionation mechanisms are local redistribution, reworking, and diagenetic mobilization. Large fractions of the Fe, Co, and Re and perhaps a small amount of Pd and Au appear to be terrestrially derived, but nearly all of the Ni, Os, Ir, and Pt must be derived from an extraterrestrial source. Only the basal layers at Caravaca and Stevns Klint, Denmark, are representative of the initial fallout and integrated Ir fluences across entire sections can be misleading. These suggest a concentration oft 120mg/g projectile in the fallout and a global fluence of chondritic matter oft 140mg cm−2.
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