Authigenic beryllium isotopes in maar lake sediments response to climate change since the last deglaciation

The timing, amplitude, and mechanisms of rapid climate changes since the last deglaciation remain elusive. Here we present well dated, high resolution lacustrine sediment ¹⁰Be/⁹Be ratio and major elements records of East Asia’s climate variability from Maar Lake Xiaolongwan, Northeast China. The abrupt increase in concentrations of Al, Ca, and Ti, considered proxies for aeolian dust flux, intriguingly coincides with a significant enhancement of the East Asian summer monsoon since the onset of the Bølling-Allerød interstadial. Combining previous analyses of dust provenance, we argue that this pattern likely attributes to heightened Central Asian dust input driven by winter-spring southwest winds and increased precipitation controlled by summer monsoon. The abrupt vegetation prosperity at the beginning of the Holocene Optimum, as evidenced by an increase in total organic carbon and total nitrogen, could have reduced the concentration of Mg, Fe, Al, and ⁹Be derived from the weathering of surrounding basaltic bedrock. The identified abrupt decreases in precipitation in northeastern China, inferred from our ¹⁰Be/⁹Be precipitation proxy, are consistent with known Dansgaard-Oeschger and Bond events in the North Atlantic region since the last deglaciation. This supports that global cooling events since the last deglaciation may be linked to a complex interplay between the intertropical convergence zone, El Niño events, and the Atlantic meridional overturning circulation.