塔里木盆地罗布泊地区石炭系混合沉积层序

The Mixed Sedimentary Sequences of Carboniferous in Luobubo Area of Tarim Basin.

对塔里木盆地罗布泊凹陷北部的石炭系露头剖面进行了野外详细实测,根据古生物特征,岩性、岩相分析和地层对比,对地层层位进行了划分、对比。由露头区向覆盖区进行了地震追踪,证实覆盖区内也有石炭系分布。古生物、岩性、岩相、沉积构造和粒度等资料证实,本区石炭系在垂向上发育典型的滨浅海碎屑岩和台地相碳酸盐岩互层的混合沉积层序。总结出了适合这种混合沉积层序的相模式,依据这种相模式对本剖面石炭纪的岩相古地理进行了简单分析。在这种典型的沉积层序中,发育着良好的烃源岩和储集层,使研究区内的石炭系具备了有利的生储盖组合条件,具有良好的油气勘探远景。

The field outcrop section of Carboniferous in northern Luobubo seg of Tarim basin was measured in detail. And the formation horizon was classified and correlated based on the paleontological feature,lithological and petrographic analyses and stratigraphic correlation. It is confirmed from seismic trace and Luobei section connected to areal coverage that there exists Carboniferous sequence distributed within the areal coverage. The integrated characteristic analyses of paleontology,lithology and lithofacies as well as grain size suggest that a mixed sedimentary sequence with interbedded typical shallow offshore clastic rock and platformal carbonate rock of Carboniferous is vertically developed in this area,providing the facies model suitable to this sequence. Based on this model,an analysis of sedimentary facies on this section is made,followed by simple evaluation of its lithofacies palaeogeography. The results show that in this typical sedimentary sequence,hydrocarbon source rocks and reservoir are fairly developed,which have great significance in petroleum geology; their probably favorable source,reservoir,cap assemblages mean better hydrocarbon potentials in this area.