Kelly, D. Clay and Elkins-Tanton, Linda T. (2004): Bottle-green microtektites from the South Tasman Rise; deep-sea evidence for an impact event near the Miocene/Pliocene boundary

Leg/Site/Hole:
ODP 189
ODP 189 1169
Identifier:
2005-041184
georefid

Creator:
Kelly, D. Clay
University of Wisconsin-Madison, Department of Geology and Geophysics, Madison, WI, United States
author

Elkins-Tanton, Linda T.
Brown University, United States
author

Identification:
Bottle-green microtektites from the South Tasman Rise; deep-sea evidence for an impact event near the Miocene/Pliocene boundary
2004
Meteoritics & Planetary Science
Meteoritical Society, Fayetteville, AR, United States
39
12
1921-1929
Forty-eight bottle-green microtektites (BGMTs) were found in a core sample recovered from Ocean Drilling Program Site 1169, located along the western flank of the South Tasman Rise in the southeastern Indian Ocean. Biostratigraphic evidence loosely constrains the age of the Site 1169 BGMTs to an interval spanning the late-middle Miocene to earliest Pliocene (12.1-4.6 Ma); incomplete core recovery and a major stratigraphic hiatus prevented a more precise age determination. This broad range of biostratigraphic ages indicates that these microtektites predate the Australasian strewn layer by at least 3.83 Ma, and perhaps by as much as 11.33 Ma. Furthermore, the REE signatures of the Site 1169 BGMTs are incongruent with those of typical Australasian ejecta, indicating that the Site 1169 BGMTs are not part of the larger Australasian strewn field. Among the various australite subgroups, the Site 1169 BGMTs are most similar in age to the HNa/K australites. However, numerous compositional discrepancies indicate that these two ejecta populations are also unrelated; the great distances separating Site 1169 from HNa/K australite-bearing localities also makes a shared provenance unlikely. Therefore, we conclude that the Site 1169 BGMTs were formed by a late Miocene impact that is distinctly separate from the Australasian and HNa/K australite events, though the location of this impact is unknown.
English
Serial
Coverage:Geographic coordinates:
North:-47.0400
West:145.1400East: 145.1400
South:-47.0400

Stratigraphy; Geochemistry of rocks, soils, and sediments; biostratigraphy; Cenozoic; cores; deep-sea environment; ejecta; Foraminifera; geochemistry; green material; impacts; Indian Ocean; Invertebrata; Leg 189; lower Pliocene; major elements; marine environment; marine sediments; metals; microfossils; microtektites; Miocene; Miocene-Pliocene boundary; Neogene; Ocean Drilling Program; ODP Site 1169; planktonic taxa; Pliocene; Protista; rare earths; sediments; South Tasman Rise; southeastern Indian Ocean; statistical analysis; stratigraphic boundary; tektites; Tertiary; trace elements; upper Miocene;

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