Publication Date:
2006-02-01
Description:
Analysis of multichannel seismic reflection profiles reveals that the northern East China Sea shelf basin experienced two phases of rifting, followed by regional subsidence. The initial rifting in the Late Cretaceous created a series of grabens and half grabens, filled by alluvial and fluviolacustrine deposits. Regional uplift and folding (Yuquan movement) in the late Eocene–early Oligocene terminated the initial rifting. Rifting resumed in the early Oligocene, while alluvial and fluviolacustrine deposition continued to prevail. A second phase of uplift in the early Miocene terminated the rifting, marking the transition to the postrift phase. The early postrift phase (early Miocene–late Miocene) is characterized by regional subsidence and westward and northwestward marine transgression. Inversion (Longjing movement) in the late Miocene interrupted the postrift subsidence, resulting in an extensive thrust-fold belt in the eastern part of the area. The entire area entered a stage of regional subsidence again and has become a broad continental shelf. Source rocks include synrift lacustrine facies, fluvial shales, and coal beds. Synrift fluvial, lacustrine, and deltaic deposits, postrift littoral and/or shallow-marine sandstones, and fractured basement have the potential to provide reservoirs. Various types of hydrocarbon traps (e.g., faulted anticlines, overthrusts, rollover anticlines, faults, unconformity traps, combination structural-stratigraphic traps, weathered basement, and stratigraphic traps) are recognized, but many of these traps have not been tested. Gwang H. Lee is an associate professor in the Department of Environmental Exploration Engineering at Pukyong National University, Korea. He received his Ph.D. in geological and geophysical oceanography from Texas A&M University in 1990. From 1991 to 1994, he worked as an exploration geologist for Shell Offshore Inc. His main research interest is the application of seismic reflection to basin research and oil and gas exploration.Booyong Kim received his B.S. degree (1992) in geology from Kyungpook National University and his M.S. degree (2002) in geophysics from Texas A&M University. He has worked for the Korea National Oil Corporation (KNOC) as an exploration geologist since 1993. He has 12 years of experience in the interpretation of seismic data primarily from the Ulleung Basin and the South Yellow Sea Basin. Kook Sun Shin is an exploration manager of KNOC. He received his Ph.D. (2001) in geology from Yonsei University, Korea. He has worked for KNOC for more than 17 years for various offshore basins of Korea (East Sea and Japan Sea, Yellow Sea, and South Sea). He also worked as a development geologist at the Captain field, North Sea, operated jointly by KNOC and Texaco. Don Sunwoo is a senior researcher at the Korea Institute of Geoscience and Mineral Resources. He received his M.S. degree (1990) and his Ph.D. (1995) in geophysics from Purdue University and from Texas A&M University, respectively. His research interests include gravity and magnetics and seismic data interpretation.
Print ISSN:
0149-1423
Electronic ISSN:
1943-2674
Topics:
Geosciences
Permalink