Characteristics and geochronology of volcanic rocks of Batamayineishan Formation in Kalamaily, Eastern Junggar, Xinjiang.
Characteristics and geochronology of volcanic rocks of Batamayineishan Formation in Kalamaily, Eastern Junggar, Xinjiang.
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作者：
T. Jia
准噶尔盆地东部及邻区广泛分布着巴塔玛依内山组火山岩。是五彩湾陆东地区大气田的主要储集层。对比两个实测剖面和一个井岩性剖面，巴塔玛依内山组陆相火山岩具有明显的多期性，火山活动间歇性受沉积夹层的干扰，是不连续界面的主要标志。火山岩的厚度在不同地区差异很大，不仅在岩性上变化很大，而且在岩相上也变化很大。岩石化学分析表明，岩石类型以基性-中性岩为主，属亚碱性-碱性富钾系列。本文用SHRIMP锆石U-Pb年代学方法测定了350.0 Ma±6.3 Ma的火山岩年龄。结合上覆地层的化石证据，认为巴塔玛依山组为下石炭统。
The volcanic rocks of the Batamayineishan Formation are widely distributed in eastern Junggar Basin and its neighboring margins. It is the main reservoir of giant gas field in Ludong, Wucaiwan area. Comparing two measured sections and a well lithologic section, the continental volcanic rocks of Batamayineishan Formation are obviously multiple stages and intermittent volcanic activities interrupted by the sedimentary interbeds which are the main indicators of discontinuous interfaces. The thickness of the volcanic rocks vary greatly in different places, changing dramatically not only in lithology but also in lithofacies. Petrochemical analysis suggests the rock types are mainly basic-intermediate which belongs to subalkaline-alkaline and K rich series. This paper report a 350.0±6.3 Ma age of volcanic rock by the SHRIMP zircon U-Pb geochronology. Combined with the fossil evidences from the overlying strata, it can be concluded that the Batamayineishan Formation is the Lower Carboniferous.