Paleozoic tectonics and sediment sources of the Ouachita fold belt, Arkansas-Oklahoma and West Texas: An isotopic and trace element geochemical study.

Persistent Link:
http://hdl.handle.net/10150/186844
Title:
Paleozoic tectonics and sediment sources of the Ouachita fold belt, Arkansas-Oklahoma and West Texas: An isotopic and trace element geochemical study.
Author:
Gleason, James Donald.
Issue Date:
1994
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Ordovician through Pennsylvanian strata of the Ouachita and Marathon sedimentary sequences show correlated Nd-Sr isotopic relations, Th/Sc ratios and REE patterns typical of evolved upper crustal sources, indicating that the 2000 km long Ouachita-Marathon fold belt consists primarily of recycled crustal materials. wi thin this sequence, Nd isotopes distinguish three distinct provenance groups: 1) Lower to Middle Ordovician hemipelagites and quartzose turbidites with ε(Nd)(t) = -13 to -16 (T(DM) = 1.8 to 2.1 Ga); 2) Upper Ordovician through Pennsylvanian hemipelagites and quartzolithic turbidites with ε(Nd)(t) = -6 to -10 (TOM = 1.4 to 1.7 Ga); 3) Mississippian tuffs with ε(Nd)(t) = -2 (TOM = 1.1 Ga). These data record a rapid Ordovician (ca. 450 Ma) shift in sedimentary sources within the off-shelf passive-margin sequence of deep-marine cherts and shales. Ouachita Silurian turbidites (ε(Nd) = -7 to -8) are isotopically identical to Middle Ordovician Taconic turbidites of the Sevier basin (Tellico Formation) in eastern Tennessee (ε(Nd) = -7 to -8), suggesting that Appalachian clastic wedges supplied Ouachita deep-sea turbidites beginning in the Late Ordovician. Pennsylvanian non-marine sandstones and shales from the Arkoma, Illinois, and Black Warrior basins have ε(Nd) = -7.5 to -10.0, similar to the thick (>10-12 km) Ouachita Carboniferous turbidite flysch sequence (ε(Nd) -7.5 to -9.6). The remarkable isotopic homogeneity of sediments delivered to the Ouachita-Appalachian region over this period implies extremely effective mixing and dispersal processes on a large (continent-wide) scale, consistent with a collisional belt provenance. A long-lived (ca. 150 Ma) tectonic link between the Appalachians and Ouachitas is thus implied by these data. Mississippian silicic ash-flow tuffs have trace-element and Nd isotopic compositions consistent with a continental-margin arc source. The active volcanic arc which erupted these tuffs apparently extended at least 1000 km from the Ouachita region to south of the Marathon region, but did not supply a significant component of the flysch. The data are consistent with submarine fan models of Ouachita flysch sedimentation demonstrating dominantly longitudinal transport down the axis of a Carboniferous remnant ocean basin from sources to the east. A model is proposed for the evolving Ouachita-Marathon suture between Laurentia and Gondwana, expanding upon Graham et a1. (1975), whereby dominantly Appalachian-derived seafloor detritus was swept up along the flanks of an approaching arc-trench system into sUbduction complexes and recycled incrementally along the length of the collision zone into the Marathon region.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Geology, Structural -- Arkansas.; Geology, Structural -- Oklahoma.; Geology, Structural -- Texas.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Patchett, P.Jon

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titlePaleozoic tectonics and sediment sources of the Ouachita fold belt, Arkansas-Oklahoma and West Texas: An isotopic and trace element geochemical study.en_US
dc.creatorGleason, James Donald.en_US
dc.contributor.authorGleason, James Donald.en_US
dc.date.issued1994en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractOrdovician through Pennsylvanian strata of the Ouachita and Marathon sedimentary sequences show correlated Nd-Sr isotopic relations, Th/Sc ratios and REE patterns typical of evolved upper crustal sources, indicating that the 2000 km long Ouachita-Marathon fold belt consists primarily of recycled crustal materials. wi thin this sequence, Nd isotopes distinguish three distinct provenance groups: 1) Lower to Middle Ordovician hemipelagites and quartzose turbidites with ε(Nd)(t) = -13 to -16 (T(DM) = 1.8 to 2.1 Ga); 2) Upper Ordovician through Pennsylvanian hemipelagites and quartzolithic turbidites with ε(Nd)(t) = -6 to -10 (TOM = 1.4 to 1.7 Ga); 3) Mississippian tuffs with ε(Nd)(t) = -2 (TOM = 1.1 Ga). These data record a rapid Ordovician (ca. 450 Ma) shift in sedimentary sources within the off-shelf passive-margin sequence of deep-marine cherts and shales. Ouachita Silurian turbidites (ε(Nd) = -7 to -8) are isotopically identical to Middle Ordovician Taconic turbidites of the Sevier basin (Tellico Formation) in eastern Tennessee (ε(Nd) = -7 to -8), suggesting that Appalachian clastic wedges supplied Ouachita deep-sea turbidites beginning in the Late Ordovician. Pennsylvanian non-marine sandstones and shales from the Arkoma, Illinois, and Black Warrior basins have ε(Nd) = -7.5 to -10.0, similar to the thick (>10-12 km) Ouachita Carboniferous turbidite flysch sequence (ε(Nd) -7.5 to -9.6). The remarkable isotopic homogeneity of sediments delivered to the Ouachita-Appalachian region over this period implies extremely effective mixing and dispersal processes on a large (continent-wide) scale, consistent with a collisional belt provenance. A long-lived (ca. 150 Ma) tectonic link between the Appalachians and Ouachitas is thus implied by these data. Mississippian silicic ash-flow tuffs have trace-element and Nd isotopic compositions consistent with a continental-margin arc source. The active volcanic arc which erupted these tuffs apparently extended at least 1000 km from the Ouachita region to south of the Marathon region, but did not supply a significant component of the flysch. The data are consistent with submarine fan models of Ouachita flysch sedimentation demonstrating dominantly longitudinal transport down the axis of a Carboniferous remnant ocean basin from sources to the east. A model is proposed for the evolving Ouachita-Marathon suture between Laurentia and Gondwana, expanding upon Graham et a1. (1975), whereby dominantly Appalachian-derived seafloor detritus was swept up along the flanks of an approaching arc-trench system into sUbduction complexes and recycled incrementally along the length of the collision zone into the Marathon region.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGeology, Structural -- Arkansas.en_US
dc.subjectGeology, Structural -- Oklahoma.en_US
dc.subjectGeology, Structural -- Texas.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairPatchett, P.Jonen_US
dc.contributor.committeememberRuiz, Joaquinen_US
dc.contributor.committeememberBarton, Mark D.en_US
dc.contributor.committeememberGehrels, George E.en_US
dc.contributor.committeememberDickinson, William R.en_US
dc.contributor.committeememberConey, Peter J.en_US
dc.identifier.proquest9506977en_US
dc.identifier.oclc703279285en_US
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