柴达木盆地正星介爆发点与上油砂山组底界的确定

Syprideis Breaking-Out Point and Determination of Upper Youshashan Formation Bottom Boundary in Qaidam Basin

根据生物爆发等时性的原则,提出了柴达木盆地风西构造上油砂山组与下油砂山组对比的新界线,以这一原则对比到红沟子构造沟5井,提出了该井井深4000m上下的下干柴沟组油层应划为上干柴沟组油层。在岩屑录井微体化石地层对比中,提出了绘制正星介丰度曲线和通过识别正星介属出现的爆发点来对比地层的新方法。

Based on the principle of biogenetic isochronism, new boundary between Upper and Lower Youshashan formations in Fengxi structure of Qaidam basin is presented. Using this principle for correlation of G-5 Well in Honggouzi structure, the Lower Ganchaigou formation at depth of about 4 000 m in this well should be classified into the Upper Ganchaigou formation. By strata correlation of microfossils from cutting logging, Cyprideis abundance curve is plotted and new method for strata correlation through identification of Cyprideis breaking-out point is proposed.