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根据以往的研究成果,分析了塔里木盆地各主要构造单元古生代以来的地质热历史。时间尺度上,塔里木盆地自古生代以来古地温总体呈下降趋势,其间存在两个相对较高的古地温期,一个是寒武纪—早奥陶世,另一个是石炭—二叠纪。早古生代塔里木盆地古地温梯度较高,寒武纪—早奥陶世为3.2～3.5℃/100m,此后地温梯度显著下降;石炭—二叠纪古地温略有上升,地温梯度可能达到3～3.2℃/100m;中生代古地温梯度下降平缓,中生代末地温梯度为2.5℃/100m左右;新生代地温梯度持续下降,现今地温梯度为2℃/100m左右。空间尺度上,塔里木盆地各构造单元的地质热历史各具特征。塔里木盆地的地质热历史与其构造演化史密切相关。
According to the previous research results, the geothermal history of all major tectonic units in the Tarim Basin since Paleozoic was analyzed. On the time scale, the paleo-geothermal temperature in the Tarim Basin has been declining since the Paleozoic. There are two relatively high Paleo-Geothermal periods, one from the Cambrian to the Early Ordovician and the other from the Carboniferous to Permian. The Paleozoic Tarim Basin had a higher paleogeothermal gradient, with a Cambrian-Early Ordovician temperature of 3.2 ~ 3.5 ℃ / 100m, and a significant decrease of the geothermal gradient since then. The Paleo-Permian paleo-geothermal temperature slightly increased and the geothermal gradient could reach 3 ~ 3.2 ℃ / 100m. The Mesozoic paleo-geothermal gradient decreased gently. The geothermal gradient at the end of Mesozoic was about 2.5 ℃ / 100m. The geothermal gradient of Cenozoic decreased continuously. Now the geothermal gradient is about 2 ℃ / 100m. On the spatial scale, the geothermal thermal history of each tectonic unit in the Tarim Basin has its own characteristics. The thermal history of the Tarim Basin is closely related to its tectonic evolution.