PROVENANCE OF CARBONIFEROUS SEDIMENTARY ROCKS IN THE BLACK WARRIOR BASIN AND ALLEGHANIAN FOLD-THRUST BELT, ALABAMA, USA

The Ouachita and Alleghanian orogenies occurred as the collision of Laurentia and Gondwana progressed from Mississippian to Permian time. Juxtaposition of the two orogenic fronts in Alabama has led to differing interpretations of sediment provenance in the adjacent Black Warrior basin and Alleghanian fold-thrust belt. Sedimentary rocks deposited in the Black Warrior basin have been interpreted to have an Ouachita, Appalachian, and NW interior craton source; while rocks deposited concurrently in the adjacent Appalachian fold-thrust belt are interpreted to have a southern Appalachian source. Previous provenance interpretations are derived from petrography, facies, and paleocurrent data. The purpose of this study is to characterize the provenance of Mississippian and Pennsylvanian foreland basin sandstones in Alabama using new quantitative detrital zircon geochronology techniques.

In this study, we use multidimensional scaling (DZmds) and inverse Monte Carlo modeling (DZmix) to quantitatively compare the detrital zircon age spectra of samples taken from the Black Warrior basin and Alleghanian fold-thrust belt to those of potential source samples. Potential source samples include pre-Pennsylvanian rocks taken from the Ouachita Mountains, and also the southern, central, and northern Appalachian Mountains. Our findings show that Carboniferous sedimentary strata in northern Alabama likely had multiple source regions with most sediment appearing to be derived from distal Appalachian sources to the north. No samples from either Black Warrior basin or Alleghanian fold-thrust belt sedimentary rocks show significant contributions from the Ouachita orogen.