新疆库鲁克塔格地区新元古代层序地层学研究及对比  

Neoproterozoic sequence stratigraphy and correlation in Quruqtagh area, Xinjiang.

作　　者：何金有[1] 徐备[1] 孟祥英[2] 寇晓威[2] 刘兵[1] 王宇[1] 米合[3] 

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室,北京100871 [2]吉林省第三地质调查所,四平136000 [3]河北省地勘局第三地质大队,张家口075000

出　　处：《岩石学报》2007年第7期1645-1654,共10页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(批准号:40572133;40032010)资助。

摘　　要：新疆库鲁克塔格地区上元古界可分为五个沉积层序,由下到上分别对应于贝义西组、照壁山组、阿勒通沟组、特瑞爱肯组至水泉组和汉格尔乔克组。第1层序由贝义西组构成,发育由粗碎屑斜坡扇和低水位楔构成的低水位体系域,向上逐渐变为粉砂岩、泥岩的海进体系域,并以向上变粗的退积准层序的高水位体系域结束,反映陆缘发展初期海平面的升降变化。第2层序由照壁山组构成,底部为粗粒石英砂岩,向上变为细粒砂岩、页岩互层,上部出现厚约30m 的泥岩,顶部为紫红色砂岩,代表了由低水位经快速海进到高水位的变化过程,整体为水体较浅的滨浅海沉积环境。第3层序由阿勒通沟组构成,为冰成杂砾岩、砂岩、页岩组合,顶部出现厚2～3m 的白云岩,沉积主体为低水位体系域,顶部白云岩为海进体系域,缺失高水位体系域。第4层序发育最为完整,特瑞爱肯组冰成杂砾岩为低水位体系域,冰成杂砾岩之上"盖帽碳酸盐岩"为海进体系域,扎摩克提组浊积岩、育肯沟组页岩、水泉组碳酸盐岩为高水位体系域,其中育肯沟组页岩为凝缩段沉积。第5层序低水位体系域由汉格尔乔克组冰成杂砾岩构成,顶部泥灰岩和白云岩为海进体系域,由于顶部被寒武系不整合覆盖,缺失高水位体系域。研究区上元古界层序基本可以和我国华南及印度 Lesser Himalaya 地区对比。According to the study on outcrop sequence stratigraphy of the Neoproterozoic strata in Quruqtagh area, five depositional sequences are recognized. In ascending order, the sequences correspond to the Bayixi, Zhaobishan, Ahungol, Tereeken to Shuiquan, and Hankalchough formations, respectively. The Bayisi Formation （ Sq1 ） contains the lowstand system tract （LST） consisted by slope fan （SF） with gritstones and lowstand wedge （LW）, the transgressive system tract （TST） consisted by siltstones and mudstones, and the highstand system tract （HST） consisted by coarsening-upward parasequences, implying the relative changes of sea level during the early stage of continent margin. The Zhaobishan Formation （Sq2）, composed by coarse-grained sandstones at the base then thin mudstones and followed by mauve sandstones upwards, suggests a forming processes of the system tract from LST, through fast transgression, to HST. The Ahungol Formation （Sq3） contains a LST of diamictites, sandstones and mudstones and a TST composed by 2 -3m dolomites at the top. The HST is absent. The sequence 4 （Sq4） is complete, which is consisted by the diamictites of the Terreken Formation （LST） then the cap carbonates （TST） above the diamictites and followed by the turbidites of the Zhamoketi Formation, the shales of the Yukkengol Formation and the carbonates of the Shuiquan Formation（HST）. The Yukkengol Formation is considered as the condensed section （CS）. The sequence 5 （ Sq5 ） only includes LST and TST, composed by the diamictites and dolomites of Hankalchough Formation, respectively. Its upper boundary is the unconformity between the Hankalchough Formation and the Cambrian. The Neoproterozoic sequences in the study area are correlated with the south China and India Lesser Himalaya areas.

关 键 词：层序地层学 新元古代 库鲁克塔格 新疆 

分 类 号：P539.2[天文地球—古生物学与地层学]