裂变径迹、同位素年龄研究苏皖周边隆起构造抬升

利用裂变径迹测年、同位素测年等研究了苏皖周边的江南隆起、张八岭隆起、苏鲁隆起在不同地质年代发生的不同级别构造抬升。研究表明,这些隆起虽然出露元古代地层,然而并非持久存在的"古隆起",而是有过"隆升-夷平-沉积-再隆升"经历的古、今隆起。包括三大隆起在内的苏皖下扬子区曾大面积覆盖古生界、上白垩统、下第三系等沉积物,由于印支—早燕山运动,始新世中期的真武事件(51Ma)和渐新世(38～24Ma)沉积间断等导致了目前海相、陆相盆地的分割和残存。

STUDY ON THE TECTONIC UPLIFT OF THE PERIPHERAL UPHEAVAL IN JIANGSU AND ANHUI BY USING FISSION TRACK AND ISOTOPES DATING METHODS

In this paper, the tectonic uplift of Jiangnan, Zhangbaling and Sulu upheavals in Jiangsu and Anhui, occurring in different ages and to various degrees, has been investigated based on fission track and isotope dating data. It is demonstrated that Jiangnan palaeo-land was inexistent in Paleozoic deposition period, and the upheavals were outcropped in Proterozoic strata, but they didn't simply undergo the uplifting process for a long period, instead, they underwent complicated processes, i.e., uplifting-leveling off-depositing-uplifting again. It is pointed out that Anhui and Jiangsu region were covered extensively by Paleozoic, upper Cretaceous and lower Tertiary strata, and then the tectonic uplifting occurred at the end of Indosinian epoch to early Yanshanian epoch. The Indosinian-Early Yanshanian orogeny, together with the Eocene Zhenwu event at 51 Ma and the Oligocene deposition cessation for a period of 38～24 Ma, led to division and remaining of terrestrial and marine basins of difference ages.