| dc.description.abstract | Chuhuangkeng anticline which located at NW Taiwan had been a major oil and gas producing field in the past. Rapid uplift caused by local tectonic activity thus formed the Chuhuangkeng anticline in the foreland basin. Because of its favorable tectonic trapping and organic maturation had reached oil window, the reservoir rocks still possess good HC potential. The purpose of this study is to understand the evolution of foreland basin, it is crucial to evaluate the depositional and thermal history of sedimentary basin and further knowing the generation and migration of oil and gas. Sequences of outcrop and borehole samples were collected in this study. Various analytical methods including XRD, petrographic thin section, vitrinite reflectance, and fission track analysis were combined to examine depositional and thermal history of the foreland basin which evolved to anticline. The results of petrographic and XRD analysis indicate that mineral composition in Chuhuangkeng anticline sequence is mostly quartz (49-89%), some lithic fragments (9-48%) and feldspar (0-4%). It had experienced series of cyclothems and started receiving orogenic sediments during Plio-Pleistocene. However, illite crystallinity has an unclear trend in Chuhuangkeng anticline sequence duo to the complicate evolution environment of foreland basin. Furthermore, organic maturation exhibits linear correlation with depth in boreholes (Ro=0.71~1.45%), which indicates that burial was the main controlling factor of thermal history. The calculated paleogeothermal gradient ranges from 40°C/km to 24°C/km, and the converted thickness of tectonic rift and exhumation is about 2.5 km. Moreover, pooled age of zircon fission track (PL-CL) is about 103.7 Ma, the origin of sediments is related to volcanic activity during lower Cretaceous to upper Cretaceous (120-80 Ma) in southeastern China. Integration of data from vitrinite reflectance and apatite fission track analysis indicates tectonic uplift process started from 4 Ma until now. Finally, the development of Houlong river should be earlier than the deposition of Cholan Formation, across central part of Chuhuangkeng anticline. | en_US |