Framework of Sequence Stratigraphy , Sedimentary System and Evolution of Cretaceous Hefei Basin

Key words: 
• Hefei Basin /
• Cretaceous /
• sequence stratigraphy /
• Zhuxiang Formation /
• Xiangdaopu Formation /
• Zhangqiao Formation

Abstract: According to seismic, welllogs, outcrop & cores data, we identified sequence stratigraphy boundarys. CretaceousPaleogene strata can be recognized as 3 firstorder sequence, 1 secondorder sequences and 4 thirdorder sequences. Based on the principle of base level cycles，the author distinguished & established sequence stratigraphy framework, sedimentary system setting & evolution in CretaceousPaleogene.That is: 1) Early Cretaceous sequence series(Zhuxiang & Xiangdaopu Formations): a semigraben basin which onlapped in the west & faulted in the east, developed great scale alluvial fanalluvial plaindelta plain on the westernnorthern & westernsouthern respecially. On eastern & easternnorthern growth aseries fandeltas & shore semideepdeep lacustrine. 2) Late Cretaceous sequence series(Zhangqiao Formation): similar with Early Cretaceous basically,buta semigraben basin which onlapped in the south & faulted in the north more salience.3) Paleogene Sequence series(Dingyuan Formation): The north of Feizhong fault uplift since tectonic movement so that bisect the basin, Dingyuan depression on the north and Shucheng depression on the south.