T224 Early and Middle Triassic Restructuring Following the End-Permian Mass Extinction (Posters)

Tuesday, 3 November 2015
9:00 AM - 6:30 PM
Exhibit Hall

USING DRONE TECHNOLOGY TO CHARACTERIZE THE KATBERG SANDSTONE ABOVE THE PERMIAN–TRIASSIC BOUNDARY AT OLD WAPADSBERG PASS, KAROO BASIN, SOUTH AFRICA

Paper number: T224-2
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

The Karoo Basin in South Africa is one of several localities where terrestrial records of the vertebrate-defined Permian–Triassic Mass Extinction are exposed. A reported change in fluvial style, from meandering to anabranching channel architecture, is believed to be associated with the event in this basin and elsewhere. Above the reported boundary lies the Katberg Formation, interpreted to represent the fluvial systems of the earliest Triassic. However, only a few studies that document the lithology and stratigraphy of this formation have been published, due to its inaccessibility and the difficulty in using conventional field methodology. As such, the relationship of these sandstone bodies across the region has not yet been fully assessed.

A remotely controlled aerial quadcopter was deployed at Old Wapadsberg Pass, Eastern Cape Province, to obtain comprehensive digital images and videos of the Katberg Formation, exposed as ledges at high elevations. Software processing of images include Adobe Photoshop and AgiSoft’s PhotoScan. Resultant photomosaics of these exposures show that the first prominent sandstone body attains a thickness of > 20 m, in which thick, high-angle crossbedding occurs. This channel system appears to have been multi-storied with internal features different from channels reported from Carlton Heights and elsewhere.

Using a combination of our digital records, measured stratigraphic columns, and thin section analyses, our data indicate that current interpretations of these post-extinction sandstone bodies may require modification. The features we have documented in the sandstone exposure at Old Wapadsberg Pass imply that the river systems above the vertebrate-defined Permian–Triassic boundary in this part of the basin cannot exclusively be classified as shallow regimes as previously published, and do not reflect architectures conforming to anabranching river systems.