牙形类化石因具微小、量多、硬度高、抗风化等特点,有时会在合适的沉积环境及外营力地质作用中,出现较老时代的分子混入其上覆较新地层中的再沉积现象。位于塔河油田沙雅隆起的奥陶系富产牙形类,由于长期存在北山南海退缩式的古地理格局,北剥蚀区外地质营力的频繁作用伴生多期古风化壳形成,导致南区一些钻井中陆续发现牙形类的再沉积现象。表现出两种形式:一种为多口井常可见到不同时代的分子混杂堆积;一种则为该油田目前独有特定时代的牙形类混生现象,在S87井中表现为达瑞威尔阶一间房组Pygodus serrus带再沉积于凯迪阶良里塔格组中,S112-1井表现为奥陶系桑比阶恰尔巴克组Pygodus anserinus带再沉积于志留系鲁丹阶柯坪塔格组中。由于迄今国内外尚无这种因再沉积而反常的“成带”现象记录,加之这一生物地层特例又有佐证塔河油田地质背景的实际意义。因此将两口井材料辅以图影成文报导,并对其成因及在油气勘探上的应用也作初步分析和讨论。 Because of its small size, high volume, high hardness and anti-weathering, the conodont-type fossils sometimes appear in the proper sedimentary environment and external tectonic geology. Deposition phenomenon. Due to the long-standing degenerated palaeogeomorphic pattern in the Beishan South China Sea and the frequent occurrence of geological causation outside the northern eroded area, the Ordovician-rich fauna associated with the Shaya uplift in the Tahe oilfield is accompanied by the formation of multi-stage paleoclimate crusts, Some drilling in succession to the discovery of dentition re-deposition phenomenon. There are two kinds of forms: one is that many kinds of molecules can often be seen in different wells at different times, and the other is a mixed albumen phenomenon that is unique in the oil field at a specific time. In the S87 well, A group of Pygodus serrus belt was re-deposited in the Kaidi-Liulitage Formation. The S112-1 well was characterized by re-deposition of the Pygodus anserinus zone of the Ordovician Cyclocene Jiarubake Formation in the Rundai Keluping Formation of the Silurian Grid group. Due to the fact that there is no record of “banding” phenomenon due to redeposition at home and abroad so far, combined with the special case of this biostratigraphy, there is evidence of the practical significance of the geological background of Tahe Oilfield. Therefore, the two well materials were supplemented with illustrations and reports, and their causes and their application in oil and gas exploration were also analyzed and discussed.