"Siliciclastic strata exposed in the Ozark Dome provide Late Cambrian to Late Cretaceous snapshots of an evolving paleogeology and regional to far-field tectonic events. U-Pb ages of detrital zircons from the arkosic base of the Upper Cambrian Lamotte Formation reflect first cycle derivation from the adjacent ca. 1.31-1.48 Ga Granite-Rhyolite province, with subsidiary input from ca. 1.6-1.7 Ga Mazatzal basement. Feldspathic arenites near the top of the Lamotte Sandstone also contain significant quantities of detrital zircon grains of these ages, with additional peaks centered at ca. 2.7 and ca. 1.1 Ga, signaling the onset of extra-regional detrital input most likely ultimately derived from the Superior Province and the Midcontinent rift. Ordovician orthoquartzites of the Roubidoux, St. Peter, and Oil Creek formations feature ca. 2.7 and ca. 1.1 Ga peaks more prominently than the Lamotte Sandstone, suggesting an increasing proportion of northerly-derive. Detrital zircon age spectra from Devonian (Bushberg Sandstone), Mississippian (Aux Vases Sandstone) units show a smoothly decreasing proportion of ca. 2.7 Ga grains and an increasing amount of 1.0-1.3 Ga and 500-360 Ma grains with time, marking the arrival of detritus derived from the uplifting Appalachian basement. In aggregate, detrital rocks in the Ozark Dome reflect an evolving depositional environment involving two significant provenance shifts: 1) a Cambrian-Ordovician shift from local basement- to Superior Province- and MidContinent Rift-derived detritus, attributed to changes in base level associated with transgression and regression of the Sauk sea and 2) Devonian shift to detritus sourced from the emerging Appalachian Mountains to the east. Westward transport of clastic sediment originating from the Appalachian highlands continued sporadically until at least Early Mississippian time"--Abstract, page iii.
Chapman, Alan D.
Hogan, John Patrick
Wronkiewicz, David J.
Geosciences and Geological and Petroleum Engineering
M.S. in Geology
Missouri University of Science and Technology
vii, 69 pages
© 2016 Bing Li, All rights reserved.
Thesis - Open Access
Electronic OCLC #
Li, Bing, "Paleogeogra detrital zircon geochronology of Upper Cambrian to Lower Mississippian siliciclastic strata of the Ozark Dome and vicinity" (2016). Masters Theses. 7741.