Branched glycerol dialkyl glycerol tetraethers and paleoenvironmental reconstruction in Zoigê peat sediments during the last 150 years

Branched glycerol dialkyl glycerol tetraethers (GDGTs) were analyzed in peat samples taken from the Zoigê grassland, located on the eastern margin of the Qinghai-Tibetan Plateau. The mean annual air temperature (MAAT) and pH in the 210 Pb-dating peat core were reconstructed based on the cyclization of branched tetraethers (CBT) and methylation of branched tetraethers (MBT) indices for the last 150 years. The results showed that the MAAT and pH values involved three stages of variation over the last 150 year...