塔里木盆地顺北地区二叠纪火山活动期次与分布

Volcanic activity stages and distribution during the Permian in the Shunbei area, Tarim Basin

肖重阳 杨林 林波 尤东华

XIAO Chongyang YANG Lin LIN Bo YOU Donghua

成都理工大学 能源学院, 成都 610059 中国石化 西北油田分公司 勘探开发研究院, 乌鲁木齐 830011 油气藏地质及开发工程国家重点实验室, 成都 610059 中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

College of Energy, Chengdu University of Technology, Chengdu, Sichuan 610059, China SINOPEC Northwest Oilfield Branch Company, Urumqi, Xinjiang 830011, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Chengdu, Sichuan 610059, China Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

顺北地区位于塔里木盆地中部顺托果勒低隆，该区为玄武岩与英安岩的叠合覆盖区，其二叠系火山岩期次及分布较塔河及塔中地区更难识别。通过对顺北地区27口井中二叠系火山岩的取心观察与采样，并进行薄片鉴定及地球化学元素分析，识别出玄武岩类、安山岩类、英安岩类、凝灰岩类和火山角砾岩类5种基本岩石类型。另外，依据二叠系火山岩的岩性组合与岩电特征对应关系，结合二叠系地震特征将火山活动细分为5个喷发旋回（或期次）：第一期为中酸性火山碎屑岩沉积，以顺北三维区为中心；第二期为基性火山岩，分布主要受古地貌变化影响；第三、四期次火山主要为锥形、盾形中酸性火山熔岩，中间以稳定分布的火山沉积岩层为划分依据；第五期为基性火山熔岩，主要分布于研究区东部。

The Shunbei area, located in the Shuntuoguole Low Uplift in the central Tarim Basin, is covered by superimposed basalt and dacite, where volcanic activity stages in the Permian and areal distribution are more difficult to identify compared with those in the Tahe and Tazhong areas. Through core observations and sampling of Permian volcanic rocks from 27 wells in the Shunbei area, we carried out thin section identifications and geochemical element analyses. Five basic rock types were observed, including basalts, andesites, dacites, tuffs and volcanic breccias. In addition, the volcanic activity was subdivided into 5 eruption cycles (or periods) based on the lithology, the petrophysical log characteristics and the seismic characteristics of the Permian section. The first stage was an eruption of intermediate-acid pyroclastic rocks, with the eruption center located in the Shunbei 3D block. The second stage was an eruption of basic volcanic rocks, which was mainly controlled by paleotopo-graphy. The third and fourth stages featured cone-shaped and shield-shaped intermediate-acid volcanic lava, with stable volcanic sediments between the two stages. The fifth stage was an eruption of basic volcanic lava, which mainly distributed in the east of the study area.

国家“十三五”科技重大专项 2017ZX05005-002;第63批博士后科学基金面上项目 2018M6331865

https://doi.org/10.11781/sysydz202002177