Late Quaternary cyclic aridity in tropical Australia

Abstract

During the numerous Quaternary sea level fluctuations, the vast Gulf of Carpentaria, in northern Australia, was more often a large lacustrine basin than a shallow sea. Recovery of aeolian quartz particles in a core spanning the last 40,000 calibrated years of sedimentation identifies a ∼2,600 year cyclic pattern of aridity. The most pronounced period peaks around 21,500 calibrated years BP, corresponding to the onstart of the period of lowest global sea level and glacial advance in New Zealand. The following peak of aeolian dust activity in Carpentaria just precedes the termination of the low sea level stand at 19,300 calibrated years BP. The timing of aeolian activity in northern Australia does not coincide with Heinrich events HE 1 to 3 recognised in the Atlantic Ocean, nor with the cyclicity of Chilean glacial activity, thus suggesting that separate 'forces' engender those different phenomena.