冷底辟与热底辟地震信息
|
摘要
冷底辟是指盐、膏、泥岩等塑性地层向上侵入或刺穿所产生的构造样式;热底辟主要指岩浆侵入或喷发所产生的底辟构造样式。不论哪种底辟构造,在人工地震剖面上反映均非常明显,其底辟内部呈杂乱反射,而围岩反射界面在此突然中断。在岩浆底辟处常出现磁力高异常,并有较高的层速度,冷底辟具有较低的层速度,盐膏底辟也具有较高的层速度。构造与火山地震关系密切,而冷底辟也可以形成破坏性地震,是今后值得注意的研究课题。
Under the effect of external force,plastic layers in subsurface and deep crust would result in diapirism,and the resulting structure is called diapiric structure,which can be divided into two types according to their nature,one is cold diapir and other is hot diapir.Cold diapir is defined here as the structural style resulting from diapirism or upward movement of plastic material such as salt,gypsum and shale.Hot diapir is defined as the diapiric structural style resulting from magmatic intrusion or explosion.Both of them are characterized with chaotic internal reflection pattern and rapid termination of reflections relevant to surrounding rock in seismic section.Magmatic diapirism is commonly associated with high magnetic anomaly and high interval velocity.Some cold diapir is associated with low interval velocity,but the diapir resulting from gypsum is associated with high interval velocity.Hot diapir is undoubtedly linked to volcanic earthquake.Cold diapir can also result in disastrous earthquake which is commonly omitted by geologist.Such examples include:two earthquakes with MS 7 and MS 6 respectively taking place in Luntai(located in the front belt of South Tianshan Mts.between Koerle and Wushi)in 1949;the northeast Baicheng earthquake with MS 7 in 1949;the south Baicheng earthquake with MS 6 in 1947;and the Wushi earthquake with MS 6.5 in 1969.The earthquakes mentioned above are obviously controlled by the large fault belt in the south of depression at the front of South Tianshan Mts.Among them,the Baicheng fault is a rootless one which is associated with Paleogene gypsum flow and upward movement.It is inferred that south Baicheng earthquake is related to the fault.Therefore,people working in seismogeology should pay more attention to the study of cold diapirism.
Under the effect of external force,plastic layers in subsurface and deep crust would result in diapirism,and the resulting structure is called diapiric structure,which can be divided into two types according to their nature,one is cold diapir and other is hot diapir.Cold diapir is defined here as the structural style resulting from diapirism or upward movement of plastic material such as salt,gypsum and shale.Hot diapir is defined as the diapiric structural style resulting from magmatic intrusion or explosion.Both of them are characterized with chaotic internal reflection pattern and rapid termination of reflections relevant to surrounding rock in seismic section.Magmatic diapirism is commonly associated with high magnetic anomaly and high interval velocity.Some cold diapir is associated with low interval velocity,but the diapir resulting from gypsum is associated with high interval velocity.Hot diapir is undoubtedly linked to volcanic earthquake.Cold diapir can also result in disastrous earthquake which is commonly omitted by geologist.Such examples include:two earthquakes with MS 7 and MS 6 respectively taking place in Luntai(located in the front belt of South Tianshan Mts.between Koerle and Wushi)in 1949;the northeast Baicheng earthquake with MS 7 in 1949;the south Baicheng earthquake with MS 6 in 1947;and the Wushi earthquake with MS 6.5 in 1969.The earthquakes mentioned above are obviously controlled by the large fault belt in the south of depression at the front of South Tianshan Mts.Among them,the Baicheng fault is a rootless one which is associated with Paleogene gypsum flow and upward movement.It is inferred that south Baicheng earthquake is related to the fault.Therefore,people working in seismogeology should pay more attention to the study of cold diapirism.
引文
龚再升.1997.中国近海大油气田[M].北京:石油工业出版社.GONG Zai-sheng.1997.Larger Oil and Gas Field in Offshore of China[M].Petroleum Industry Press,Beijing(inChinese).
蒋笑霞.1991.中国东部沉积盆地特殊岩性体的地震描述[J].石油地震地质,3(1):94—106.JIANG Xiao-xia.1991.Seismic delineation of special lithologic body developed in the eastern China basins[J].Petro-leum Seismic Geology,3(1):94—106(in Chinese).
刘魁元,康仁华,武恒志,等.2000.罗151井区侵入岩油藏储集层分布及成藏特征[J].石油勘探与开发,27(6):16—18.LIUKui-yuan,KANG Ren-hua,WUHeng-zhi,et al.2000.The character of reservoir rock distribution and formation inintrusion reservoir in the area of Luo151well[J].Petroleum Exploration and Development,27(6):16—18(inChinese).
王文谈.1992.阿北火山地震资料的地质解释[J].石油地震地质,4(1):33—43.WANG Wen-tan.1992.Geologic interpretation of Abei volcano in seismic section[J].Petroleum Seismic Geology,4(1):33—43(in Chinese).
辛连发.1985.蒙古林构造储集层地震特征研究[J].石油地震地质1(2):91—98.XIN Lian-fa.1985.Seismic character study of reservoir in Mengulin structure[J].Petroleum Seismic Geology,1(2):91—98(in Chinese).
中国科学院地质研究所.1974.中国地震地质概论[M].北京:科学出版社.Institute of Geology,Chinese Academy of Sciences.1974.An Introduction to Seismology and Geology of China[M].Science Press,Beijing(in Chinese).
蒋笑霞.1991.中国东部沉积盆地特殊岩性体的地震描述[J].石油地震地质,3(1):94—106.JIANG Xiao-xia.1991.Seismic delineation of special lithologic body developed in the eastern China basins[J].Petro-leum Seismic Geology,3(1):94—106(in Chinese).
刘魁元,康仁华,武恒志,等.2000.罗151井区侵入岩油藏储集层分布及成藏特征[J].石油勘探与开发,27(6):16—18.LIUKui-yuan,KANG Ren-hua,WUHeng-zhi,et al.2000.The character of reservoir rock distribution and formation inintrusion reservoir in the area of Luo151well[J].Petroleum Exploration and Development,27(6):16—18(inChinese).
王文谈.1992.阿北火山地震资料的地质解释[J].石油地震地质,4(1):33—43.WANG Wen-tan.1992.Geologic interpretation of Abei volcano in seismic section[J].Petroleum Seismic Geology,4(1):33—43(in Chinese).
辛连发.1985.蒙古林构造储集层地震特征研究[J].石油地震地质1(2):91—98.XIN Lian-fa.1985.Seismic character study of reservoir in Mengulin structure[J].Petroleum Seismic Geology,1(2):91—98(in Chinese).
中国科学院地质研究所.1974.中国地震地质概论[M].北京:科学出版社.Institute of Geology,Chinese Academy of Sciences.1974.An Introduction to Seismology and Geology of China[M].Science Press,Beijing(in Chinese).
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心