Integrated provenance study of the Austin Glen Member and the Taconian Orogeny

Conference · Tue Mar 01 04:00:00 EST 1994 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:7059463

Bock, B; McLennan, S M; Hanson, G N ^[1]

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1. State Univ. of New York, Stony Brook, NY (United States). Dept. of Earth and Space Sciences

The Austin Glen Member of the Ordovician Normanskill Formation was deposited in the Appalachian foreland basin in response to the Taconian Orogeny. The exact sources of the Austin Glen turbidites are not known, but the two permissible endmember source components may allow one to place tectonic constraints on the Taconian Orogeny. The first and probably dominant component is derived indirectly via recycled sedimentary rocks from Laurentia. A second source could be the approaching outboard terrane and its related rocks. The Laurentian-derived source component itself might be a complex mixture of Archean, Early and Middle Proterozoic crustal provinces and Late Proterozoic rifted margin sequences. Little is known about the geochemistry and isotopic composition of the possible outboard component(s). Nevertheless, if these two principal sources have petrographically, geochemically or isotopically different signatures, it will be possible to identify specific source components and perhaps provide tectonic constraints on the Taconian orogeny. Petrography of the matrix-rich sandstones indicates that they were derived dominantly from recycled sedimentary rocks. No plutonic and only sparse volcanic rock fragments could be observed, whereas a high percentage number of sedimentary and metasedimentary rock fragments is present. Geochemical analyses of the samples indicate that in contrast to Ordovician flysch, in Canada, no ophiolitic source components were contributed to the New York portion of the basin. The tectonic setting of the Austin Glen Member is therefore best explained as a dynamic environment in which sediment derived from Laurentia was rapidly recycled and mixed with sediment derived from an outboard source.

• OSTI ID: 7059463
• Report Number(s): CONF-9404221--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 26:4
• Country of Publication: United States
• Language: English

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