Our MEAS Department Seminar will be in Biltmore 2010 (for the entire Fall Semester) at 330PM, Monday, August 26, in-person and via Zoom. 

Speaker – Doug Watkins, Geomorphology, and he will be hosted by Ethan Hyland.

Bio – Doug Watkins is a consulting petroleum geologist who hails from the sandhills of Scotland County, North Carolina. He has over forty-five years’ experience in all aspects of the upstream petroleum exploration business. Early work in onshore domestic trends was followed by overseas assignments in Asia, the Middle East and Europe. His areas of functional exploration expertise include prospect generation, integrated regional studies, exploration team leadership, field appraisal/development and upstream operations. His current work on the Carolina Bays has resulted in the Barchan Dune Model for Bay origin. Mr. Watkins is a member of AAPG, GSA, Houston Geological Society and was a founding member and the first Secretary of the Dhahran (Saudi Arabia) Geological Society. He holds a Bachelor of Science degree in Geology from Tulane University.

Seminar Title – Carolina Bays: Born in the lee of Pleistocene eolian barchan dunes- a new model from Scotland County, NC

Abstract – Carolina Bays, the well-known shallow elliptical depressions along the Atlantic seaboard, have been described by many authors advocating a myriad of interpretations. Yet, no single model fully explains the origin, sedimentation, subsidence, size, orientation and ellipticity of these extraordinary features. This study proposes that the Carolina Bays of Scotland County, NC are consequent features of eolian barchan sand dunes, part of a broad Pleistocene desert (erg) that developed during glacial sea level low stands on the arid sandy Carolina coastal peneplain. In the wind shadow leeward of the barchans, an elliptical area (the Bay) of dark, fine-grained sediments settled and accumulated due to wind velocity drop across the dune face. The orientation of the parent barchan dunes and subsequent Bays indicate a wind field from the southeast. Differential compaction of the fine-grained Bay sediments was the initial cause of Bay subsidence; a basal aquiclude thus formed is a common Bay feature. After dune migration ceased, fine sediments continued to accumulate leeward of the barchans, where early vegetation was established. Further compaction, subsidence, soil formation, diagenesis and the development of interglacial temperate peat bogs (and related lakes) indurated/anchored the accumulating and subsiding Bay sediments; thus, the Bay was resistant to subaerial (and paleo-littoral?) erosion that redistributed the barchan dunes and other unconsolidated desert sands. Typical remnant dune features include a sandy southeastern Bay lobe (the remnant barchan), sand rims and ubiquitous inter-Bay sheet sands. Hence, most direct evidence of the barchans has been removed. However, one largely intact barchan dune, with 20 feet of current topographical relief, its adjacent Bay to the northwest, occurs in Scotland County and is presented. This dune has withstood erosion/deflation due to its large size and location above the local erosional fluvial floodplain. Further studies on this feature should validate this as a viable model for Carolina Bay formation. An exposed peat-rich Bay sedimentary sequence will also be shown. Vintage air photos and new LiDAR point cloud mapping have proven excellent tools in identifying the Bays, remnant barchans and related sand bodies, including parabolic dune fields. The study results, the barchan/Bay model and modern analogs will be presented.