Abstract: Carbon and oxygen stable isotope analyses on Eocene to Holocene carbonates from the Qaidam Basin at the northeastern edge of the Tibetan plateau in Western China show several distinct events related to regional climate and tectonism involving in the formation and uplift of the Tibetan plateau. The stable isotope record of the thick Cenozoic lacustrine-terrestrial sedimentary sequence indicates that the climates of Miocene were dominated by arid conditions. Carbon isotope data of the Hongsanhan section reveal two small and short cycles of 1 Ma to 3 Ma duration. Based on the results of stable isotope data, four distinct tectonic events can be detected: (1) An increase of the δ¹³C and δ¹⁸O values in Late stage of Shangganchaigou Formation should corespond to the surrounding mountain uplifting; (2) A sharp decrease both δ¹³C and δ¹⁸O values around the boundary between the Shangganchaigou Formation and Xiayoushashan Formation reveal a height increase of the whole basin and the uplifting event of Himalaya at ca. 24 Ma; (3) Positive isotopic ratios at 19 Ma to 18 Ma coincide with the strongest uplifting of the Altyn Mountains and the subsidence of the basin, resulting in drought climate; (4) Another height increase of the whole basin is documented by highly negative ratios at 12 Ma with the pronounced basin subsidence and relative mountain uplifting.

Key words: Tibetan plateau, Qaidam Basin, stable isotope, uplift