Geochemical features of meteorite impact around the Eocene/Oligocene boundary layer in the central East Pacific

Author(s): Yin Yanhong; Wan Tianfeng; Sun Jiashi
Author Affiliation(s): Primary:
Qingdao Institute of Marine Geology, Qingdao, China
China University of Geosciences, China
Volume Title: Zhongguo Haiyang Daxue Xuebao
Source: Zhongguo Haiyang Daxue Xuebao, 34(2), p.281-288. Publisher: Ocean University of China, Qingdao, China. ISSN: 1672-5174
Note: In Chinese with English summary. 8 refs.; illus., incl. 3 tables, sketch maps
Summary: The geochemical features of the strata from the Upper Eocene to Lower Oligocene in the central eastern Pacific are studied by analysing the samples from the Site 573 provided by the ODP and other information in this area. The boundary layer between the Eocene and Oligocene is a layer of metalliferous claystone which is about 3.4 m thick. The metalliferous claystone is of special geological and geochemical characteristics and contains abundant Fe and Fe-group elements such as Ni, Co and Ir, which may imply that this layer was formed by an extraterrestrial impact. Microspherules (microtektites or microkrystites) are also found in the layer, especially at the bottom of the layer. These characteristics indicate that the formation of the metalliferous claystone may have some relationship with meteorite impact. According to the characteristics and composition of the strata between the Late Eocene and the Early Oligocene, the extinction of many organisms, and the distribution of microspherules, we suggest that a catastrophic event might have occurred at the end of the Eocene in the central Eastern Pacific. The catastrophic event may have been caused by a meteorite that impacted the Pacific Plate.
Year of Publication: 2004
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 05 Petrology, Igneous and Metamorphic; Cenozoic; Chemical composition; DSDP Site 573; Deep Sea Drilling Project; East Pacific; Eocene; Geochemical anomalies; Geochemistry; IPOD; Impacts; Leg 85; Lower Oligocene; Meteorites; Microtektites; Oligocene; Pacific Ocean; Paleogene; Stratigraphic boundary; Tektites; Tertiary; Upper Eocene
Coordinates: N002955 N002955 W1331834 W1331854
Record ID: 2004085783
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