西南石油大学学报(自然科学版)

• 地质勘探 • 上一篇    下一篇

伊犁盆地下石炭统阿克沙克组白云岩特征

瞿建华1 *,余朝丰2,李啸1,丁靖1,唐勇1   

  1. 1. 中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000
    2. 中国石油杭州地质研究院,浙江杭州310023
  • 出版日期:2015-02-01 发布日期:2015-02-01
  • 通讯作者: 瞿建华,E-mail:qujianh@petrochina.com.cn

A Research on Characteristics of Dolostones in Akeshake
Formation,Lower Carboniferous,Ili Basin

Qu Jianhua1*, Yu Chaofeng2, Li Xiao1, Ding Jing1, Tang Yong1   

  1. 1. Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China
    2. Hangzhou Institute of Petroleum Geology,PetroChina,Hangzhou,Zhejiang 310023,China
  • Online:2015-02-01 Published:2015-02-01

摘要:

伊犁盆地是北疆地区石炭系碳酸盐岩最发育的地区,分布范围及厚度均较大。通过野外露头观测发现伊犁盆
地白云岩分布广泛,纵向上主要发育于阿克沙克上亚组第二岩性段,平面上主要分布(但不限于)于台地边缘礁滩相范
围。盆地南部相对较发育,其厚度、规模及延伸也远较北部大,与断裂或晚期侵入体关系密切。薄片观察发现白云岩
多为粉—细晶结构,以细晶为主,块状构造,按粒级分主要为细晶白云岩。通过对白云岩、灰质白云岩和灰岩稀土元
素配分模式的对比,发现3 种岩石曲线形态很相似,表明白云岩和灰岩有紧密的内在联系。根据 δCe 推测灰岩形成于
相对还原的环境,而白云岩形成于相对氧化的环境。综合分析认为研究区白云岩的成因类型为热液白云岩。

关键词: 伊犁盆地, 阿克沙克组, 白云岩特征, 成因类型

Abstract:

Ili Basin is an area where the carbonate is best developed in north Xinjiang,both the distribution range and the
depth being large. By observing outcrops,we found that dolostones was widely distributed in ILi Basin,with 2nd of Akeshake
upper-subunit developed lengthways,and distributed in(but not all)platform edge shallow facies. There developed dolostones
in south of basin,with bigger thickness,scale and expansion range than northern part,which is closely related to fracture or
later intrusions. Lamella observation indicates that dolostones are mainly in powder-fine grain texture,the majority of which
is finegrain,with block structure,and carbonate with larger type of rocks are fine grain dolostones according to size fraction.
Through contrasting the rare earth element distribution pattern of the dolomite,gray matter dolomite and limestone,we found
the three rock curve shapes are very similar,which make clear that there is close inner link between dolomite and limestone.
According to the δCe we conjecture the limestone is formed from the deoxidation environment and the dolomite is formed from
the oxidation environment. In conclusion,the genetic type of the dolomite in the research area is hydrothermal dolomite.

Key words: ILi Basin, Akeshake Formation, characteristic of dolostones, genetic type