新疆博格达山宽沟地区的石炭系

<正> 新疆博格达山南北坡广泛出露石炭系,上石炭统的分层系统基本确立,自下而上是:居里得楞组、柳树沟组、祁家沟组和奥尔吐组,前三个组的时代为晚石炭世早期(即三分的中石炭世),后一组的时代为晚石炭世晚期(即三分的晚石炭世)。本区是否存在下石炭统的问题,由于缺乏生物地层资料的确凿依据而长期不能肯定,其症结主要在于“宽沟组”一名造成的混乱。

The Carboniferous of the Kuangou area of the Bogda Mountain in Xin jiang

After a re-investigation into the biostratigraphy of the Kuangou section in southern Qitai County of the Xinjiang Uygur Autonomous Region, the lower Upper Permian to Upper Carboniferous of this section has been divided in descending order into the Wulapo, Tashi-kula, Shirenzigou, Aoertu, Qijiagou and Liushugou Formations, based on the exposed strata of this section, in combination with the lithological character, lithofacies, stratigraphical contact relationships and the similarity in the biotic characters between the Qijiagou, Jing-jingzigou and other sections in the southern suburb of the Urumqi City. In this section, the lowermost horizon of the strata is the Early Moscovian; no strata of the Lower Carboniferous have been found to exist therein. The "Kuangon Formation", which was named in 1960 and regarded as an Early Carboniferous stratigraphical unit of this region, actually came from the misidentification of fossils and was later incorrectly relayed among geological workers. For this reason, the name "Kuangou Formation"should be abolished.Our regional biostratigrapbical investigation into the northern slope (from the Mori River in Mori Kazak Zizhixian to Qijiagou in Urumqi City) and the southern slope (from Ta-rlang of Turpan County to Liushugou of Urumqi City) has confirmed that the lowermost horizon of the strata exposed west of Eastern Tianshan (Bogda Mountains) is the Upper Carboniferous, without any Early Carboniferous strata supported by fossil evidence so far.