Andean-type orogenic plateau as a trigger for aridification in the arcs of northeast Pangaea

Abstract

The interplay between continental motions during the assembly of Pangaea and late Palaeozoic climate change, including severe glaciation and global aridification, remains enigmatic. Here we identify the provenance of Permian–Early Triassic sediments that recorded climate change of North China and estimate palaeoelevation to constrain tectonic-climate interaction during the assembly of northeast Pangaea. Detrital zircon U-Pb-Hf analysis indicates the sediments were locally sourced from the ancient basement and associated with a late Palaeozoic (410–260 million years ago) continental arc, devoid of input from juvenile arcs of the Altaids. These sediments were interpreted as deposited in a retroarc foreland basin ascribed to subduction of the Palaeo-Asian Ocean. Crustal thickness estimated from whole-rock La/Yb yields an average value of 58 ± 11 km, which corresponds to a palaeoelevation of 3.8 ± 0.7 km. The results reveal the existence in North China of an orogenic plateau comparable to the Altiplano of the Andes that blocked moisture transport from the ocean and served as an important orographic barrier to trigger Permian aridification.