新疆库鲁克塔格地区奥陶纪岩相古地理

库鲁克塔格地区在西北地层区划上属塔里木地层区的库鲁克塔格地层分区。其沉积特点受塔里木盆地的影响，但是又不同于塔里木盆地，区内研究程度低。依据野外露头资料，本地区奥陶系南北分区明显，北区岩性为碳酸盐岩建造，生物以三叶虫、头足类、腕足类及珊瑚等浅海生物为主；南区岩性为复理石建造，生物以深海相笔石为主。从岩性、古生物、沉积构造、沉积序列、指相矿物等沉积特征可以看出，本地区奥陶纪古地貌具南低北高的特点。本地区奥陶系发育台地海相、广海陆棚相、盆地边缘斜坡相、深海盆地相、半深海相和浅海相等类型。依据各时期沉积相及其展布特征，总结出４种沉积相模式，即①台地海-广海陆棚沉积相模式；②盆地边缘海陆棚-深海盆地沉积相模式；③海陆过渡-浅海沉积相模式；④冲积扇-三角洲沉积相模式。本次研究对鲁克塔格地库区进一步的研究及找油工作打下了理论基础。

LITHOFACIES PALAEOGEOGRAPHY OF THE ORDOVICIAN IN KURUKETAGE REGION OF XINGJIANG

Kuruketage region belongs to Kuruketage stratigraphic subregion of Tarim stratigraphic region in northwest stratigraphic region classification. Its sedimentary feature was influenced by Tarim Basin, but it’s not the same as Tarim Basin’s. This area was rarely studied before. According to field outcrop data, there are obviously different between the sedimentary feature of Ordovician of north and south area of Kuruketage region. In the north area, it’s mainly of carbonate rock formation in lithology and of shallow-sea facies fossil such as Trilobita Cepohacopoda, Brachiopoda and Anthozoa in fossil feature. While in south area, it’s mainly of flysch formation in lithology and of deep-sea facies fossil such as Graptolithina in fossil feature. So it is obviously that the north area of Kuruketage region was higher than that of the south area in Ordovician period which was reflected by sedimentary feature such as lithology, ancient fossil, sedimentary structure and sedimentary sequence. In the study area, tableland sea , wide continental shelf , shelf margin slop , deep sea basin and shallow sea sedimentary facies are developed. Four sedimentary facies patterns can be deduced from sedimentary facies and its extending feature. They are tableland sea—wide continental shelf sedimentary facies pattern, basin margin slope—deep sea basin sedimentary facies pattern, sea-land transitional facies—shallow sea sedimentary facies pattern and alluvial fan—delta sedimentary facies pattern. A theory foundation is laid for further studying and oil exploration.