Stuck in a loop: investigating fabric patterns in the Stone Age gravel sequence at Canteen Kopje, Northern Cape Province, South Africa

Abstract

Canteen Kopje has long been known for its alluvial diamond-bearing gravel deposits, and historically these have featured frequently in archaeological literature over the last century. Studies have shown the site preserves a stratified gravel sequence with assemblages of Fauresmith mixed into the upper gravels, Victoria West Acheulean (1.2 ± 0.07 Ma) and two Early Acheulean assemblages (1.51 ± 0.8 Ma and > 1.51 Ma). Although previous geomorphological studies provide an understanding of site formation, most recently describing the gravels as a splay deposit at the terminal point of a palaeo-channel, or loop, there have been debates regarding their origin and whether they represent colluvial and/or alluvial deposition. This palaeo-channel facilitated the interaction between two nearby koppies and the palaeo-Vaal River, which subsequently influenced the nature, composition and character of the gravel deposits found across the site. Yet no study has investigated the visibly dipping surface of the gravels, nor sought to explain gravel fabric patterns that are preserved in exposed sequences. Through recording fabric data, this study confirms that the gravels retain an easterly dip direction, which provides strong evidence for the east-to-west flow of water from the upstream direction of the palaeo-channel. These findings challenge earlier models suggesting the upper gravels at Canteen Kopje are colluvial, and have implications for understanding the preserved Earlier Stone Age assemblages. This research also provides a better understanding of geomorphological processes involved in site formation and investigates the overall role that colluvial processes have played at Canteen Kopje.