地层缺失(lacuna)简称“缺失”,指地史时期中地层记录的比较大的明显的中断,一般指由于假整合或不整合的产生而构成的地层缺失。如由于不整合而造成的地层缺失,从时间意义上来说,停止沉积的时间也就是对老地层侵蚀破坏的时间。不仅意味着停止沉积了一段地层,而且还包含着对已沉积的老地层侵蚀破坏了一部分。例如华北中奥陶统与中石炭统之间的平行不整合,缺失了上奥陶统、志留系、泥盆系和下石炭统。这一地层缺失表明不仅中止沉积了几个系的地层,而且还侵蚀掉了一部分奥陶系地层。
地层缺失和厚度不等是基于测井数据进行井间地层自动对比中需要解决的关键问题。
Hiatus and different thickness of the same formation are two key problems on automatic stratigraphic correlation based on log data from well to well.
辽河盆地东部凹陷中段深部地层中的古近系沙河街组由沙一段、沙三段构成,缺失沙二段和沙四段。
The Shahejie Formation of the Paleogene in the deep zone of the middle area of the East Depression in Liaohe Basin is made up of its Member 1 and Member 3 and lacks its Member 2 and Member 4.
在油田开发中钻遇断层时,地质上存在将测井分层对比中缺失地层厚度与铅直地层断距混淆的现象。
The thickness of lost stratum and stratigraphic throw is apt to misuse in identification of stratum on logs.
应用推荐