辽河断陷东部凹陷钻井中含牙形石的中奥陶统马家沟组

钻探证实辽河断陷东部凹陷内,中、新生代地层之下发育厚层质纯的碳酸盐岩,是潜山油气勘探的主要目的层。经过系统选样,发现了较为丰富的牙形石化石。牙形石研究表明这套厚层质纯的碳酸盐岩地层属于中奥陶统的马家沟组,含有上部以Erraticodon tangshanensis为主,下部以Tangshanodus tangshanensis为特征的牙形石。研究还首次表明辽东太子河早古生代海盆已延伸到辽河断陷东部凹陷内部。由于这套碳酸盐岩地层具有良好的油气储集性能,因此,此研究成果对于在东部凹陷内部进一步寻找"新生古储"式潜山油气藏具有重要的指导意义。

MIDDLE ORDOVICIAN MAJIAGOU FORMATION WITH CONODONT FOSSILS FROM THE EASTERN DEPRESSION IN THE LIAOHE FAULT DEPRESSION

The recent drilling survey proves that the eastern depression in the Liaohe Fault Depression developed thick carbonate rock series under lying the Mesozoic and Cenozoic strata,which is the important target strata for the "bu-ried hill" oil and gas exploration.After systematic sampling,we found abundant conodont fossils.The conodont study indicates that the thick carbonate rock strata belongs to the Majiagou Formation of the Middle Ordovician.The Upper part of the formation has the conodont fossil Erraticodon tangshanensis,the lower part is represented by Tangshanodus tangshanensis.This study firstly demonstrates the Early Paleozoic sea basin in the Taizihe River of East Liaoning has extended into the eastern depression of the Liaohe Fault Depression.Since this carbonate rock strata has fine potentiae for oil and gas accumulation,this work shows significance for searching "buried hill" oil and gas recources in the eastern depression.