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轮东1井位于塔里木盆地塔河-轮南古隆起东翼围斜部位.该井在6800～6825m井段上奥陶统发育一高约25m的大型溶洞.第3筒芯取自洞穴顶部.通过对洞穴充填沉积序列及其古生物分析与元素地球化学研究,获以下关键结论:(1)洞穴沉积物中含较多腕足类、腹足类、棘皮类、介形虫和疑源类化石,明显分为洞穴原地生态和异地生屑(洞穴崩塌角砾经溶蚀残存与潜流搬运而来)两类,指示洞穴形成于前石炭纪,并在石炭纪再次沉降时被半充填和埋藏;(2)元素地球化学揭示,洞穴充填泥为钙质古土壤和风化壳残留物,形成于循环不畅的咸水环境;(3)洞穴形成与演化共经历了3期:晚奥陶世良里塔格组沉积后、桑塔木组沉积后和志留系沉积后,其中后两期主要发育顺层承压深潜流岩溶作用.基于洞穴形成历史恢复,可对古岩溶有利区进行预测评价.此外,对古地理学与古岩溶学研究也具有重要意义.
The Well Dong 1 is located at the anticline of the east wing of the Tahe-Lunnan paleohigh in the Tarim Basin, where a large caverns of about 25 m in height are developed in Upper Ordovician from 6800 to 6825 m, and the third core is taken from the top of the cave. The key conclusions are as follows: (1) The cave sediments contain more brachiopods, gastropods, echinoderms, ostracods and fossils of doubtful origin. By analyzing the sedimentary sequences of sedimentary caves and their paleontological analysis and elemental geochemistry, It is obviously divided into two categories, that is, the original ecology of the cave and the different kinds of raw debris (the cave rupture brecciated by erosion and subsurface flow), indicating that the cave was formed in the former Carboniferous and was semi-filled and buried when the Carboniferous subsided again. 2) Elemental geochemistry reveals that calcareous calcareous soil is filled with calcareous soil and weathered crust residues and formed in a poorly circulated saltwater environment. (3) Formation and evolution of caves have undergone three phases: the late Ordovician After the deposition of the grids, the sediments of the Sangtamu Formation and the Silurian sediments, the latter two of which are mainly undergrowth of confined pressure underdeep flow karstification.Based on the historical restoration of the cavern formation, the favorable karstification zone can be predicted and evaluated.In addition, Paleogeography and ancient karst research also has a heavy weight Meaning.