利用磷灰石裂变径迹资料反演合肥盆地古地温和估计沉降率与剥蚀率

利用合肥盆地内６个磷灰石裂变径迹样品资料，反演模拟了该盆地自侏罗纪晚期以来各时代地层古地温变化，估算了沉降率与剥蚀率．模拟结果与其他地质资料推论一致，它揭示出该盆地南北两地存在不同的构造变化和受热史，反映了大别山构造发展对盆地南北两地区影响的差异．盆地南部靠近大别山地区的晚侏罗世地层在白垩纪早期埋藏温度曾大于１２０℃；早白垩世后期的构造抬升（剥蚀率约１３０ｍ／Ｍａ）使温度降至３０-４０℃；自白垩纪后期始，该地区一直处于动荡的但总体为持续抬升的构造环境中．盆地北部地区晚侏罗世与早白垩世早期地层在白垩纪期间埋藏温度曾达到和超过１００℃，但随后的大幅度构造抬升（剥蚀率约１９０ｍ／Ｍａ）使其温度降至３０-６０℃；第三纪早期，局部区域的裂陷（沉降率约６０ｍ／Ｍａ）使温度又升至８０℃左右．指出合肥盆地构造演化大体可分形成、隆升、局部裂陷和再隆升４个阶段．

INVERSION OF THERMAL HISTORY AND EVOLUTION OF SUBSIDENCE AND EROSION RATES USING APATITE FISSION TRACK DATA IN HEFEI BASIN,ANHUI PROVINCE

Based on six specimen apatite fission track data and geological exploration data in Hefei Basin,authors inversed the geothermal variation of the sedimental rocks and evaluated the subsidence and erosion rates of the basin evolution process.The simulated results are in correspondence with the inferences from other geological data.It could be indicaetd that the tectonic development and thermal histories of the sediments In the south part of the basin differed from the north.The rocks of up Jurassic near to Dabie mountain may bear the paleotemperature up to 120℃ or more during the earlier Cretacous; the tectonic uplift and large erosion（erosion rate≈130 m/Ma） Made the paleotemperature of the rocks decreased to 30-40℃;From late Cretacous,the tectonic environment of south part of the basin was kept going on fluctuation uplift stages.But,In north part of the basin,the highest paleotempelature of late Jurassic and earlier Cretacous rocks was upto 100℃.more,and the lowest was downto 30-60℃ because of the tectonic uplift and erosion （erosion rate≈190 m/Ma, short time）during cretacous.In earlier Tertiary Period,the Paleotemperature of the rocks increased again to about 80℃ because of local rifting（the subsidence rate≈60 m/Ma）.Analyzing the thermal histories,subsidence and erosion rates and geologicalexploration data,we conclude that the tectonic evolution in Hefei Basin could be classified into four terms,formation,uplifting,local rifting and re-uplifting.