摘要
以泌阳断陷双河－赵四地区下第三系核三上段陆相层序地层学研究为例，建立了断陆湖盆陡坡带陆相层序地层学模式：①陆相层序及其体系域界面模式；②体系域模式；③陆相层序地层模式。其中，陆相层序地层模式包括岩相格架模式及年代框架模式两个内容。研究结果显示，断陷湖盆陡坡带可识别出Ⅰ型和Ⅱ型两类陆相层序；一个完整的Ⅰ型陆相层序从下往上发育ＬＳＴ、ＴＳＴ、ＨＳＴ及ＲＳＴ四个体系域，共五个界面，除顶、底界面归属层序界面之外，其它三个界面皆为体系域界面；而Ⅱ型陆相层序缺失ＬＳＴ。无论何种体系域，其沉积体的几何形状均为模状体，且各体系域的沉积相横向配置呈现规律性变化。陆相层序地层等时框架模式清晰地显示了研究区下第三系核三上段的沉积充填史及其沉积层序时空展布特征。
in this paper, the upper member of Eh_3 in Shuanghe--Zhao'ao area of Biyang fault--depression is treated as a case to study terrigenous sequence stratigraphy and to establish a terrigenous sequence stratigraphy model for the steep slope of fault--depressed lacustrine basin. The terrigenous sequence stratigraphy model is composed of boundary model, system tract model, and terrigenous sequence stratigraphic model which includes lithologic framework model and chronostratigraphic framework model. The research shows that two kinds of terrigenous sequence (i. e. type Ⅰ and type Ⅱ ) can be recognized in the steep slope of fault--depressed lacustrine basin. A complete terrigenous sequence of type I can be divided into four system tracts: Lowstand System Tract (LST) ， Trangressive SystemTract (TST), Highstand System Tract (HST) and Regressive System Tract (RST) from bottom totop, and has five boundaries in which the top and bottom belong to sequence boundary, and other threeto system tract boundary. While terrigenous sequence of type Ⅱ lacks LST. The geometrical shape ofsedimentary body in every system tract appears wedge--like, namely sedimentary wedge, and the crossconfiguration of sedimentary factes in every system tract regularly change from basin--margin to basin-inside. The chronostratigraphic framework model clearly shows that sediment--filling history and distribution character in time and space for terrigenous sequence of the Upper Member of Eh_3 in research area.
出处
《长春科技大学学报》
CSCD
1999年第2期151-156,共6页
Journal of Changchun University of Science and Technology
基金
"油气藏地质及开发工程"国家重点实验室开放基金!PLN97023
关键词
泌阳断陷
层序地层模式
陆相层序
断陷湖盆
sequence boundary model
system tract model
sequence stratigraphic model
chronostratigraphic framework model
terrigenous sequence
fault--depressed lacustrine basin
