Source and Dispersal Patterns: Paleozoic Clastic Rocks in the Southern Mid-Continent

Abstract

Collision between Laurentia and Gondwana and intervening terranes had terminated the passive margin continental slope sedimentation and formed the Ouachita Orogen and related foreland basins in the southern mid-continent during the Paleozoic. Multiple Paleozoic age clastic rocks are cropped along the southwest Missouri, northeast Oklahoma, and northwest Arkansas. Different models, including local vs. long distance transported, have been proposed to interpret the sources of those clastic rocks. In this study, a series of Ordovician to Pennsylvanian age sandstones were sampled from outcrops. LA-ICP-MS U-Pb detrital zircon geochronology was utilized to constrain sediment sources and dispersal patterns. In total 20 samples and 1300 single detrital zircon grains were analyzed. Results show that there are five distinct age groups, including 0.4–0.6 Ga, 1.0–1.2 Ga, 1.3–1.5 Ga, 1.6–1.8 Ga, and >2.5 Ga. Regional source terranes correlation suggest that the oldest group (>2.5 Ga) is attributed to the Superior Province of the Canadian Shield; the 1.6–1.8 Ga group corresponds well with Yavapai-Mazatzal provinces; the 1.3–1.5 Ga group is not tightly constrained, but may originate from a localized midcontinent source, such as the Ozark Dome; the 0.4–0.6 Ga group is believed to have originated from Acadian and Taconic Orogenies; and the 1.0–1.2 Ga range is mostly likely derived from the Grenville crystalline rocks. The Ordovician sandstones are characterized by older age groups (older than 1.0 Ga) and were interpreted as mainly recycled sources originated from the Canadian Shield. All post-Ordovician sandstones show mixed source signatures. In addition to the older age groups, 0.4–0.6 Ga age group became another primary source. In contrast to previous model, provenance change started in the Early Mississippian. All Mississippian and Pennsylvanian sandstones share same sources, either directly derived from craton and/or recycled from previous sediments source to the north and northeast.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015