Geochemical indicators of provenance and tectonic setting of Mississippian pelites of the Ouachita fold belt

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5591356

Totten, M W ^[1]; Blatt, H; Weaver, B L ^[2]

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1. Univ. of New Orleans, LA (United States)
2. Univ. of Oklahoma, Norman, OK (United States)

Plate tectonic reconstructions of the southern continental margin of North America during the Paleozoic are inconclusive. Numerous conflicting models have been proposed for the opening and closing of the Iapetus Ocean and the subsequent deposition and deformation of the Ouachita System. Considerable confusion also exists concerning the provenance of the Carboniferous flysch deposits of the Ouachitas. Trace element geochemistry of shales from the Stanley Group constrain both the provenance of the sediments and the plate tectonic setting during the Mississippian evolution of the southern continental margin. Th/Sc and Cr/Th ratios support a cratonic source for the majority of samples analyzed. However, in several samples the Th/Sc ratio decreases and the Cr/Th ratio increases, suggesting a contribution from a more mafic source. Using element ratio-ratio diagrams, all of the samples plot along a curve consistent with a two-component mixing model between a felsic and a mafic source. Both a tantalum-niobium trough and a strongly negative strontium anomaly are seen in upper-crust-normalized trace element spiderdiagrams. These anomalies are also present in interbedded volcaniclastics within the Stanley. The Stanley shales also exhibit a positive vanadium-chromium-nickel anomaly. The pervasive occurrence of these anomalies is interpreted as inherited from their source, and not from diagenetic alteration or sedimentary processes.

• OSTI ID: 5591356
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GEOLOGIC FORMATIONS
GEOCHEMISTRY
PALEOZOIC ERA
PLATE TECTONICS
CARBONIFEROUS PERIOD
CHROMIUM
CONTINENTAL CRUST
CONTINENTAL MARGIN
NICKEL
NIOBIUM
NORTH AMERICA
ORIGIN
SCANDIUM
STRONTIUM
TANTALUM
THORIUM
TRACE AMOUNTS
VANADIUM
ACTINIDES
ALKALINE EARTH METALS
CHEMISTRY
EARTH CRUST
ELEMENTS
GEOLOGIC AGES
METALS
TECTONICS
TRANSITION ELEMENTS
580000* - Geosciences