【摘要】 冷科 1井是近年来柴达木盆地北缘最重要的一口科学探索井。因该井首次发现了巨厚的新地层 ,所以对该井的4 666～ 5 2 0 0m地层划分存在较大争议。前人主要依据孢粉资料把冷科 1井 4 666～ 5 2 0 0m层段归属为下侏罗统 ,也有人依据从该段发现的海相化石碎片认为该段为石炭系。本文从岩性组合、古生物特征、地震剖面、测井电性及水介质特征等多方面对该层段进行了分析 ,否定了该段为下侏罗统和石炭系的可能 ,认为该段为上三叠统。该研究改变了过去柴达木盆地始于早侏罗世的观点 ,指出柴达木盆地起始于晚三叠世零星分布的断陷沉积更多还原

【Abstract】 Lengke 1,a well for the scientific research drilling project, is the most important exploration well in the northern Qaidam basin. As great thickness of strata was for the first time discovered in the well, there is much controversy over stratigraphic division of the interval from 4 666 to 5 200 m. Based on the sporopollen assemblage, most geologists hold that the interval is of Lower Jurassic, while some others consider it to be Carboniferous according to some detritus of marine fossils found in this interval. Based on analyzing such characteristics of this interval as its lithological associations,palaeontology,seismic sections,well logging data and water medium quality,this paper rules out the possibility of being Lower Jurassic or Carboniferous,and points out that the strata in this interval are Upper Triassic. This research changes the former idea that Qaidam basin originated in Early Jurassic,and reveals that the basin originated from Late Triassic sporadic rifts.更多还原