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通过补充重点钻井前寒武系火山碎屑岩样品的锆石U—Pb定年,开展震旦纪一寒武纪初期地层对比研究,在震旦纪末古地貌格架基础上建立寒武纪初期烃源岩发育模式,并根据地震相特征推测烃源岩分布。锆石年代学结果显示T1井底火山碎屑岩样品的最年轻谐和年龄为707±8Ma,地层时代宜归南华系。寒武系底界(T_9~0面)上下地层格架显示,震旦纪末期古地貌具有以巴楚、塔中一带为隆起高地,南高北低、西高东低的特征。在古台地和斜坡部位,寒武系底部烃源岩的分布与上震旦统白云岩有较好的一致性,在古隆起及其边缘表现为沉积缺失或相变。从T_9~0界面以下地震相特征推测,西山布拉克组∈_1xs烃源岩主要分布在满加尔坳陷,而玉尔吐斯组∈_1y烃源岩在柯坪—塔北隆起、阿瓦提坳陷东部和顺托果勒地区都有分布。巴楚—塔中地区存在多个前南华系基底古隆起,广泛缺失寒武纪初期地层,整体烃源岩发育条件欠佳。麦盖提斜坡南华系—震旦系厚度大、分布广,可能有寒武系底部烃源岩分布。
By supplementing zircon U-Pb zircon dating from Precambrian pyroclastic rocks in key drilling, a stratigraphic correlation study of Early Sinian to Early Cambrian was carried out. Based on the Late Palaeogeographic framework of the Sinian, an early Cambrian period was established Source rock development model, and according to the seismic facies characteristics of hydrocarbon source rock distribution. The zircon geochronology results show that the youngest harmonic age of T1 pyroclastic samples is 707 ± 8Ma, and the age of the strata should be the South China System. The upper and lower stratigraphic frameworks at the bottom of the Cambrian (T_9 ~ 0 surface) show that the paleolatoprozoic at the end of Sinian has the characteristics of uplifted highland in the middle of Bazu and Tazhong area, high in the south and low in the north and low in the west and high in the east. At paleo-terraces and slopes, the distribution of the source rocks at the bottom of the Cambrian is in good agreement with that of the upper Sinian dolomite, and is characterized by sedimentary absence or facies change at the paleohigh and its margins. From the seismic facies below T_9 ~ 0, it is speculated that the source rock of ∈_1xs source rocks in Braeck Xishan Formation are mainly distributed in Manjiaer Depression, while the source rock of ∈_1y source rocks in Yü Tu Tuo group are uplifted in Keping- There are distributions in the eastern Hershey torre region. There are a number of pre-South China basal paleohighs in the Bachu-Tazhong area, extensively lacking the Cambrian early strata, and poor overall hydrocarbon source rock development. The Nanhua-Sinian system in the Maigaiti Slope is thick and widely distributed, possibly with the distribution of the source rocks at the bottom of the Cambrian.