Refined dating using palaeomagnetic secular variations on a lake sediment core from Guozha Co, northwestern Tibetan Plateau

Abstract

Lake sediments are widely applied to investigate palaeoclimatic and palaeoenvironmental changes on the Tibetan Plateau (TP). Radiocarbon dating of various materials is one of the most commonly used methods to constrain the timing of lake sediment deposition, but it is problematic for most lakes on the TP due to carbon reservoir effects. Because palaeomagnetic secular variations (PSV) share similar patterns at the regional scale, PSV-stratigraphic correlation can provide an alternative approach to date lake sediments. Here, we present a PSV-depth model for a sediment core taken from Guozha Co, a glacial meltwater-fed lake on the northwestern TP. To establish reliable chronological constraints on the sediment core, we compared our PSV-depth model with the PSV stack of East Asia, PSV records of Tangra Yumco and Lake Baikal. The establishment of this new chronology at Guozha Co is a major step toward dating lake records more widely in the TP to reveal palaeoclimatic changes at the world's ‘Third Pole’.