The Rietputs Formation in South Africa: A Pleistocene Fluvial Archive of Meteorite Impact Unique to the Kaapvaal Craton
MetadataShow full item record
Reconstructing the terrestrial impact cratering record is a fundamental goal of planetary science. However, erosion, burial, and deformation can obscure or destroy impact records. A sedimentary record of impact is provided by detrital shocked minerals, which have been shown to survive erosion and transport in modern alluvium and Holocene glacial deposits. Here we describe detrital shocked minerals from a known impact structure in sediments that were transported to distal locations and buried. The Rietputs Formation is a Pleistocene fluvial terrace of the Vaal River in South Africa, and shocked minerals were found in the terrace at locations up to 750 km downstream of the 2020 Ma Vredefort impact structure. Optical and electron microscopy, and U-Pb geochronology, were used to establish microstructural and isotopic provenance indicators that demonstrate the detrital shocked minerals originated from the Vredefort impact structure. The Rietputs Formation contains fluvial diamonds and Acheulean (ca. 1.7–1.3 Ma) artifacts at sites such as Canteen Kopje, a South African National Monument. The assemblage of detritus in Rietputs Formation gravels, including shocked minerals from Earth’s largest impact structure, diamonds from Cretaceous kimberlites, and Stone Age artifacts, comprises a unique sedimentary archive of the Kaapvaal craton, and may have geoheritage significance.
Showing items related by title, author, creator and subject.
Preservation of detrital shocked minerals derived from the 1.85 Ga Sudbury impact structure in modern alluvium and Holocene glacial depositsThomson, O.; Cavosie, Aaron; Moser, D.; Barker, I.; Radovan, H.; French, B. (2014)Detrital shocked minerals can provide valua ble residual records of eroded impact structures. Recent studies have reported shocked minerals in modern alluvium in a subtropical climate from the deeply eroded 2.02 Ga Vredefort ...
Fluvial transport of impact evidence from cratonic interior to passive margin: Vredefort-derived shocked zircon on the Atlantic coast of South AfricaMontalvo, S.; Cavosie, Aaron; Erickson, T.; Talavera, C. (2017)Meteorite impacts produce shocked minerals in target rocks that record diagnostic high-pressure deformation microstructures unique to hypervelocity processes. When impact craters erode, detrital shocked minerals can be ...
Identification and provenance determination of distally transported, Vredefort-derived shocked minerals in the Vaal River, South Africa using SEM and SHRIMP-RG techniquesErickson, T.; Cavosie, Aaron; Moser, D.; Barker, I.; Radovan, H.; Wooden, J. (2013)The record of meteorite impacts on Earth is incomplete due to the destruction of impact craters by erosion and burial. Shocked minerals residing in sediments may help further document the impact record. To evaluate the ...