Geothermal history of Tarim basin is closely related with its structural evolution history.Palaeogeotherm in Tarim basin has been in declining trend since Paleozoic.There were two relatively high palaeogeothermal stages

one in Cambrian-Early Ordovician and the other in Carboniferous-Permian.The palaeogeotherm in Tarim basin was relatively high during Early Paleozoic.It was 3.2℃～3.5℃ per hundred meters in Cambrian-Early Ordovician

and then remarkably lowered.It increased a little bit in Carboniferous-Permian to 3.0℃～3.2℃ per hundred meters.It slowly declined in Mesozoic and lowered to 2.5℃ per hundred meters at the end of Mesozoic.It continuously declined in Cenozoic to the current 2℃ per hundred meters.As the structural development and evolution histories are different in various structural units

the geothermal history of each structural unit in Tarim basin has distinct characteristics.Shaya

Katak and Guchengxu uplifts always had relatively high geothermal heat flow

because they had been in basement uplift area for a long period;while Manja'er depression had relatively low geothermal heat flow

because it had been in downwarping region with large burial depth of basement for a long period.Moreover

Tarim basin has experienced N-S compression in Cenozoic.As a result of the loading of mountains

the lithosphere in the central part of the basin had been upwarped

so the geothermal gradient in Katak uplift had relatively small variation or increased a little bit;while the downwarping on the edge has caused continuous and rapid subsidence of the Southwest Tarim depression in Cenozoic

as a result

the geothermal gradient lowered rapidly by a big margin.