SHIFTING SANDS: PROVENANCE CHANGES IN THE NORTHERN APPALACHIAN FORELAND BASIN

A complex network of mature fluvial systems filled the Appalachian Foreland Basin from a variety of provenance regions during the Late Mississippian-Early Pennsylvanian periods (325-315 Ma) (Archer and Grebb, 1997). This basin formed in response to the accretion of the Taconic, Avalonian, and Acadian island arcs, which eventually sutured the paleocontinents of Laurentia and Gondwana together (Becker et al., 2006). Previous research along the eastern margin of the Central Appalachian Foreland Basin by Thomas et al. (2004) and Becker et al. (2005, 2006) discusses compositions and U-Pb dated provenances, including the Acadian- and Taconic-accreted slope sediment, uplifted Greenville basement rock, and Canadian Shield. To continue this provenance research in a fluvially-mature section of the Northern Appalachian Foreland Basin, stratigraphic successions containing sandstone beds were sampled along PA State Rt. 8 in Venango County, Pennsylvania spanning the Late Mississippian-Early Pennsylvanian periods. Petrographic comparisons of quartz framework grains, lithic fragments, and cement composition were used to determine provenance changes. Point counting and QFL plots were used to compare units and to determine provenance, using methods outlined in Dickinson et al. (1983). Based on our preliminary results a fluvial model for this section of the foreland basin was produced. This research illuminates mature fluvial sediments from various provenance regions that comprise the subsurface strata in northwestern Pennsylvania during the Late Mississippian through Early Pennsylvanian periods. Future research will include U-Pb dates for the units sampled, as well as analysis of additional strata, to refine these preliminary trends and models. Understanding these sedimentary trends is integral to safe and efficient resource extraction and geologic modeling of other foreland basins in North America.