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

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.

Automated summary

In a giant lacustrine turbidite system in the Ordos Basin in northern China, it has been found that the rainfall intensity during the Carnian Pluvial Episode (CPE) greatly influenced the lacustrine turbidite deposition. Despite a temporal lag, the intensified turbidite deposition is a response to the three humid periods during the CPE. Compared to marine environments, continental depositional settings are more sensitive to humid climate changes and can provide detailed and long-term records of carbon fluctuations. This study highlights the impact of extremely humid events on turbidite deposition and contributes to the understanding of the CPE in terrestrial environments.