塔中北坡顺南5井下奥陶统锶同位素曲线及地层划分  

Strontium Isotopic Curve of the Lower Ordovician and the Chronostratigraphic Division of Well Shunnan-5 on Northern Slope of Middle Tarim Basin

作　　者：马庆佑[1] 蒋华山[1] Ma Qingyou;Jiang Huashan(Research Institute Exploration and Production, Northwest ＂Oilfield Branch of SINOPEC, Urumqi 830011, China)

机构地区：[1]中国石化西北油田分公司勘探开发研究院,乌鲁木齐830011

出　　处：《地质科技情报》2018年第1期69-73,共5页Geological Science and Technology Information

基　　金：国家科技重大专项"塔里木盆地海相黑色泥页岩地层沉积特征及其页岩气潜力研究"(2017ZX05036-001-003)

摘　　要：塔中北坡下奥陶统地层划分对深化该区沉积构造演化分析、指导该区下古生界油气勘探具有重要意义。首次利用塔中北坡顺南5井采集的45个下奥陶统锶同位素样品,获得了该井对应深度的锶同位素演化曲线,并与全球早奥陶世海水的锶同位素演化趋势进行了对比,同时根据前人建立的奥陶系87Sr/86Sr比值-年龄数据库换算出了年龄值,从而确定了该井下奥陶统鹰山组与蓬莱坝组的界线应位于井深6 950m处,为深化塔中北坡下奥陶统地层划分研究提供了参考。Studies on divisions of the Lower Ordovician strata are of great significance in deepening of sedimentary-structural evolution analysis,and guiding Paleozoic oil and gas exploration on the northern slope of middle Tarim Basin.This paper sets up an evolution curve of the strontium isotopic composition corresponding to the depth of 45 unaltered marine carbonate samples collected from Well Shunnan-5 on this northern slope.The corve is compared with the strontium isotope evolution trend of the global early Ordovician seawater.The strata age is converted according to the Ordovician data-base of 87 Sr/86 Sr ratio established previously.This study has confirmed the boundary of Yingshan-Penglaiba Formation of Lower Ordovician using the analytic data of strontium isotope of the Well Shunnan-5.The study provides reference for deepening the research of Lower Ordovician stratigraphic division on the northern slope of middle Tarim Basin.

关 键 词：锶同位素地层学 海相地层定年 顺南5井 下奥陶统 塔中北坡 

分 类 号：P597[天文地球—地球化学]