NAJNOVIJI OBJAVLJENI RADOVI

Middle Triassic lake deepening in the Ordos Basin of North China linked with global sea-level rise

Intracratonic basins such as the Triassic Ordos Basin in Central China are challenge for chronostratigraphy due to the lack of marine index fossils (i.e. ammonids) which hampers the land-sea correlations as well. The Middle Triassic Yangchang Formation represents a vast lacustrine basin that is also one of the main targets for hydrocarbon exploration in Central China. We present new palynological data, ID-TIMS ²⁰⁶Pb/²³⁸U date from ash beds, and high-resolution δ¹³C_org record from the Chang 7 unit of the Yangchang Formation that is coincident with the largest extent of the Ordos lake system. The new radiometric date of 240.95 ± 0.033 Ma suggests an early Ladinian age for the maximum deepening and expansion phase of the lacustrine system. Evidence of marine influence in the Ordos Basin at that time and comparison to the sea-level oscillations observed in Western Tethys suggest that a global eustatic rise and highstand may have played a role in determining lake-level variations.

The article is available at the following link: https://www.sciencedirect.com/science/article/pii/S0921818121002551?dgcid=coauthor