Terrestrial temperature history reveals Late Miocene rapid uplift of the northern Tibetan Plateau

Abstract

Paleoaltimetry data are essential for deciphering the growth trajectory of orogenic plateaus and underlying forcing mechanisms. However, paleoaltitude reconstructions using conventional paleotemperature analysis often have low resolution or large calibration uncertainties. Here, we use Group III alkenones, a marine paleothermometer normally not present in terrestrial basins, to reconstruct paleolake temperatures and refine the paleoelevation history of the Qaidam Basin, northern Tibetan Plateau, during the Late Miocene. Our results reveal a geologically rapid lake-surface cooling of 6.6° ± 1.8°C at either ~11.3 to 10.8 or ~7.7 to 7.6 million years ago (depending on the chronology used). This cooling, benchmarked against coeval sea surface temperatures, indicates a topographic rise of either 1650 ± 450 or 1525 ± 450 meters. Coupled with glycerol dialkyl glycerol tetraether–based paleotemperatures and existing tectonic records, our findings refine the timing and pace of a rapid uplift event within the final major phase of Tibetan Plateau growth, linked to mantle lithosphere detachment.