RETRACTED: Tectonic-sedimentary cycles and environmental evolution in Southwest Monsoon area since 2.78 Ma, recorded in a long lake sediment core from Heqing, China (Retracted Article)

The tectonic-sedimentary cycles and environmental evolution in Southwest Monsoon area since 2.78 Ma were reconstructed, based on the analyses of lithology, grain size, carbonate content, loss-on-ignition (LOI) and pollen in a 737.72 m sediment core from the Heqing Basin, China. The results indicated that the lake basin was formed in about 2.78 Ma. Continuous lacustrine sediment was pre-served since 2.65 Ma. Three stages of tectonic-sedimentary cycle were revealed, which were 2.78 1 .55, 1.55 0.99 and 0.99 0 Ma. The environmental evolution in Heqing area was influenced by uplift of the Qinghai-Tibetan Plateau, the resulting variation of Southwest Monsoon and the earth orbital-scale periodicity.