塔里木盆地演化的周期性与造山带关系初探

PRELIMINARY INVESTIGATION OF THE RELATIONSHIP BETWEEN TARIM BASIN EVOLUTIONAL PERIODICITY AND MARGINAL OROGENIC BELT

本文综合前人关于塔里木盆地地层划分的各种方案和最新研究成果，建立了塔里木盆地主要构造单元的地层年代格架，在此基础上恢复了塔中4井、满参1井、草1井残余地层的原始厚度，从而建立了这三口井时间序列剖面上的沉积速度直方图。通过对该时间剖面沉积速度直方图进行滑动平均处理，找到了100Ma的周期，这一周期控制了塔里木盆地的坳陷-隆起的构造旋回，即100Ma周期的半周期处于正相位时，盆地沉降坳陷接受沉积；而该周期的半周期处于负相位时，盆地隆起剥蚀。而且这一周期与塔里木盆地边缘造山带的开合演化史有着极好的对应关系。本文最后指出100Ma为控制塔里木盆地构造演化的最重要的周期，自寒武纪以来这一周期共有四个，并对其成因作了探讨。

On the basis of combination of previous and newly-achieved measures on the stratigraphic division of the Tarim Basin, A Chrononstratigraphic framework of some main structural units in the basin is established. Primary thicknesses of some remnant strata at Well Tazhong 4, Well Manchan 1 and Wen Chao 1 are also acquired, and the bar charts showing chronologic deposition rate at the three wells are thus plotted. Through processes on these charts, 100 Ma period which controlled the cycles of uplifting and falling of thebasin is discovered. When the half point of the 100 Ma period was at positive phase, thebasin depressed and reiceved sediments. While negative phase was imposed on the half point,the basin tended to uplift and be eroded. The period is found to coincide very much with theevolution of orogenic belt at the marginal area of Tarim, and considered the most importantperiod controlling the structural evolution of the basin. Four periods of 100 Ma are identifiedsince Cambrian, and their origin are finally analyzed.