大巴山南坡奥陶系的沉积环境分析

AN ANAIYSIS OF SEDIMENTARY ENVIRONMENTS OF THE ORDOVICIAN SYSTEM IN THE SOUTHERN SLOPE OF THE DABA MOUNTAIN

本文系统地研究了大巴山南坡奥陶系的沉积特征,详细地划分了该系各组段的沉积相,并建立了奥陶系的沉积相模式。奥陶系以发育潮坪相为特征,并有少量浅海沉积。奥陶纪时期,本区处于北为汉南古陆与巴山隆起,南为广阔的陆表海盆地的古地理环境。尽管各个时期海岸线有进有退,海水有深有浅,但盆地地形的总趋势是西北高而东南低,海侵的旋回性与沉积发展的周期性相一致。

This paper systematically studied the sedimentary features of the Ordovician system, specifically divided sedimentary facies of every formation, and found sedimentary model of the Ordovician system.The Ordovician system is characterized by the tidal flat facies with a few shallow sea facies.The natural geography of the Ordovician period is that: the Hannan paleocontinent and the Bashan Mountain rise at the north, and the wide epicontinental sea basin lies in the south.Though coast lines protrude somewhere or shrink back in other places and seawater became deep here or shallow there, the overall trend of the basin topography is high in the northwest and low in the southeast.