Intensified lacustrine turbidite deposition as a response to the Carnian Pluvial Episode: Insights from the Triassic Ordos Basin in North China Plate

Abstract

The Carnian Pluvial Episode (CPE) is a period during which the rainfall was extremely intense and greatly influenced the deposition in different sedimentary environments globally. However, the relationship between the CPE and turbidite deposition remains poorly known. Here we investigate a giant lacustrine turbidite system of the Triassic Ordos Basin in North China Plate, to determine how the CPE influenced turbidite deposition, by integrating geochronology, organic carbon isotope, major and trace elements, clay minerals and turbidite sedimentology. Results show that the lacustrine turbidite deposition in the Ordos Basin was strongly associated with the CPE. Although there is a temporal lag, the intensified turbidite deposition is considered as a response to the three humid periods during the CPE. Compared with marine environments, continental depositional settings tend to be more sensitive to the humid climate changes, and can record more detailed and long-term carbon fluctuations. This study highlights the potential for turbidite deposition affected by extremely humid events, and provides new insights into the prediction of deep-water turbidite systems. Furthermore, it enriches the theory of the CPE in terrestrial environments.