ALBERT

Description: The Kingston Peak Formation is a diamictite-bearing succession that crops out in the Death Valley region, California, USA. An exceptionally thick (〉1.5 km) outcrop belt in its type area (the Kingston Range) provides clear insights into the dynamics of mid-Cryogenian (‘Sturtian’) ice sheets in Laurentia. Seven detailed logs allow the lateral and vertical distribution of facies associations to be assessed. We recognize (1) diamictite facies association (ice-proximal glacigenic debris flows), (2) lonestone-bearing facies association (ice-marginal hemipelagic deposits and low-density gravity flows with iceberg rafting), (3) pebble to boulder conglomerate facies association (ice-proximal cogenetic glacigenic debris flows and high-density turbidites), (4) megaclast facies association (olistostrome and hemipelagic sediments subject to ice-rafting), and (5) interbedded heterolithics facies association (low-density turbidites and hemipelagic deposits). The stratigraphic motif allows three glacial cycles to be inferred across the range. Ice-minimum conditions interrupting the Kingston Peak succession are associated with the development of an olistostrome complex, succeeded by a thick accumulation of boulder conglomerates deposited during ice readvance. The data testify to a strong glacial influence on sedimentation within this ancient subaqueous succession, and to highly dynamic ice sheet behaviour with clear glacial cycles during the Sturtian glaciation.