VTechWorks staff will be away for the Memorial Day holiday on Monday, May 27, and will not be replying to requests at that time. Thank you for your patience.
Aspects of Cyclic Sedimentation in the Upper Mississippian, Mauch Chunk Group, southern West Virginia and southwest Virginia
Buller, Ty Bradford
MetadataShow full item record
Late Mississippian, Mauch Chunk Group strata constitute a westward-thinning clastic wedge of strata up to 1000m thick that developed in the Central Appalachian Basin over a ~ 7 million year time interval. Included within the Mauch Chunk Group are multiple incised-valley fills and a distinctive prodeltaic succession of laminated sandstones and mudstones. Calculated estimates of drainage basin areas for incised-valley fills in the Mauch Chunk Group range from > 1,000,000 km2 for the Stony Gap Sandstone to < 100,000 km2 for the Princeton Formation. Drainage area estimates are consistent with detrital zircon geochronology and petrographic data and suggest that the Stony Gap and Ravencliff incised-valley fills were derived from distal, northern and northwestern cratonic sources that dispersed sediment into NE-SW-oriented, longitudinal incised-valley drainages and that the Princeton Formation was derived from proximal tectonic highland sources along the eastern margin of the Appalachian Basin which dispersed sediment into a transverse incised-valley. The Pride Shale overlies the Princeton incised valley fill and records a hierarchy of tidal periodicities is preserved in the Pride Shale. Microlaminated, semi-diurnal sandstone-siltstone/shale couplets record the dominant ebb tide of the day. Up to 17 semi-diurnal couplets are stacked into neap-spring (fortnightly) tidal cycles. Neap-spring cycles are arranged in thickening and thinning that record seasonal cycles driven by the annual monsoon. Total organic carbon (TOC) values are a proxy for annual climatic cycles. TOC contents are higher within intermonsoonal and lower within monsoonal components of annual cycles reflecting, respectively, lesser and greater dilution by terrestrial flux.
- Masters Theses