273-14 The Devil's Point Event from beyond San Salvador

See more from this Division: Topical Sessions
See more from this Session: From San Salvador and Beyond: A Tribute to Don and Kathy Gerace and the Development of the Gerace Research Centre

Tuesday, 7 October 2008: 4:45 PM
George R. Brown Convention Center, 342AD

Benjamin J. Greenstein, Dept. of Geology, Cornell College, Mt Vernon, IA
Abstract:
Paleontological evidence for a double peak in sea level during the Last Interglacial (119-128 ka) was first discovered on San Salvador in June 1992. Additional evidence for a hiatus in reef building was published subsequently for Great Inagua Island, designated it as the Devil's Point Event (DPE) and established an initial geochronology. A subsequent review of the literature suggested that the double peak observed in the Bahamas might be a global phenomenon. More recent work extended the reach of the double peak to include Barbados. Here I present evidence for a double peak preserved in the Pleistocene Tantabiddi Limestone of coastal Western Australia.

Coral reef deposits of Late Pleistocene age are exposed in Southern Exmouth Gulf, the western side of Cape Range and, sporadically, further south along the Western Australia coast. In southern Exmouth Gulf, the erosion surface occurs 2-3 m above present sea level and is developed on top of a coral reef facies that often exhibits spectacular preservation of corals in situ. A paleosol, in variable stages of development, occurs sporadically on top of the erosion surface. The erosion surface or paleosol, if present, are overlain by a second marine sequence represented by either coral rubble or bioclastic-siliciclastic sandstone.

Stratigraphic evidence for a double peak in sea level also occurs north of Cape Cuvier on the coast of Western Australia, at an elevation approximately 10 m above current sea level. The sequences are interpreted to represent the Devil's Point Event at both localities and establish as a global phenomenon the double peak originally observed on San Salvador Island. Hence profound climatic and oceanographic instability occurred during the close of Late Pleistocene time. Additionally, the different elevations of the DPE surface on either side of the Cape Range suggest tectonism has occurred in the region since Late Pleistocene time.

See more from this Division: Topical Sessions
See more from this Session: From San Salvador and Beyond: A Tribute to Don and Kathy Gerace and the Development of the Gerace Research Centre