Distribution of glycerol dialkyl glycerol tetraethers in surface sediments of Lake Qinghai and surrounding soil

► iGDGTs were abundant in the alkalescent surface soil around Lake Qinghai. ► TEX86 decreased along an onshore soil-nearshore-offshore sediment transect. ► MBT and CBT increased along the transect. ► In situ production of bGDGTs occurs in the saline Lake Qinghai. ► Terrestrial iGDGT input to offshore sediments appears minor.