西湖凹陷东部断阶带的地质结构与演化
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摘要
通过对横穿断阶带的地震剖面的认真研究发现，作为西湖凹陷东部边界的断阶带在渐新世末之前并不是一个统一体，只是在经过龙井运动一幕（Ｔ４２）之后才形成今日之面貌。断阶带东侧的钓鱼岛隆褶带中部存在经岩浆侵入而复杂化的早第三纪地层。断阶带上的局部构造大多数形成于渐新世末（Ｔ４２），以断背斜、逆牵引背斜为主，大部分局部构造因岩浆侵入和断裂作用而复杂化，对油气的保存十分不利
On the basis of careful studies of seismic sections across the fault zone in the east of the Xihu depression,it is discovered that the fault zone,as the boundary of the Xihu depression,was not a whole before the end of Oligocene.Only after the first episode of Longjing motion did the fault zone become connected.At the middle part of Diaoyudao Uplift to the east of the fault zone,are Early Tertiary strata in which magmatic intrusion is found.Most of local structures in the fault zone were formed at the end of Oligocene(T 4 2).Among them,fault anticlines and reverse drag anticlines prevail.Because most structures were destroyed by magmatic intrusions and faults,it is very difficult for these structures to preserve oil and gas.
On the basis of careful studies of seismic sections across the fault zone in the east of the Xihu depression,it is discovered that the fault zone,as the boundary of the Xihu depression,was not a whole before the end of Oligocene.Only after the first episode of Longjing motion did the fault zone become connected.At the middle part of Diaoyudao Uplift to the east of the fault zone,are Early Tertiary strata in which magmatic intrusion is found.Most of local structures in the fault zone were formed at the end of Oligocene(T 4 2).Among them,fault anticlines and reverse drag anticlines prevail.Because most structures were destroyed by magmatic intrusions and faults,it is very difficult for these structures to preserve oil and gas.
引文
1王舒畋等。冲绳海槽盆地的地质构造特征与盆地演化历史。海洋地质与第四纪地质，1986，6（2）：17—30。2许薇玲等。东海的构造运动及演化。海洋地质与第四纪地质，1988，8（1）：9—22。3龚建明等。西湖凹陷东部断阶带火成岩的分布特征。中国海上油气，1995，9（1）：13—17。4冯锐等。东海与黄海的三维速度结构及其构造意义。地质学报，1993，67（1）：19—35。
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