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在许多地质条件下，低镁方解石质的海相碳酸盐岩能保存其原始的化学元素和同位素组成，化学地层学与生物地层学相结合，有可能成为远距离、大区域之间海相地层精确划分与对比的工具。塔里木盆地英买力、轮南和塔中地区下古生界缺乏标准化石，重要油气产层（东河塘组）的时代归属长期难以定论。选择古生物地层学研究较详细的柯坪地表剖面，建立其下古生界稳定同位素组成曲线，与塔中、轮南地区钻井剖面下古生界稳定同位素组成曲线对比，参考微体古生物证据，较精确地划分了中、上奥陶统与下奥陶统的界线。根据塔中地区探井中极少量牙形石化石分布，在泥盆系与石炭系可能的分界线附近集中采样分析，建立化学元素分布曲线，与化学生物地层学研究较详细的２条华南古生界剖面（贵州长顺县睦化剖面，湖南祁阳县黎家坪剖面）对比；根据３条剖面都出现的Ｓｒ元素含量异常与华南剖面标准化石带的关系，确定塔中地区泥盆系与石炭系的分界线位于东河塘组顶面之上５１．５ｍ处。图３参７（梁大新摘）
In many geological conditions, low-Mg calcite marine carbonate rocks can preserve their original chemical elements and isotopic composition. The combination of chemical stratigraphy and bio-stratigraphy may lead to long-range, large-area marine Stratum accurate division and contrast tools. There is a lack of standard fossils in Yingpai Li, Lunnan and Tazhong areas of the Tarim Basin. The era of important oil and gas formations (Donghutang Formation) has long been hard to determine. The Paleontology stratigraphy was selected to study the Keping surface profile in detail. The stable isotopic composition curve of the Lower Paleozoic was established. Comparing with the Paleozoic stable isotope compositions under the drilling section in Tazhong and Lunnan, Accurately divided the Middle and Upper Ordovician and the Lower Ordovician line. Based on the extremely small distribution of conodont fossils in the exploratory wells in the Tazhong area, a centralized sample analysis was conducted near the possible demarcation line between the Devonian and Carboniferous to establish a chemical element distribution curve. Two South China ancient Based on the correlation between the anomalous Sr content in three sections and the standard fossil zone in South China section, the authors have determined the relationship between the Devonian and the Devonian in the Tazhong area The Carboniferous boundary is located at 51.5m above the top of Dongtangtang Formation. Figure 3 Reference 7 (Liang Daxin Abstract)