摘要
The Gulong-1 well lies in the platform margin slope in Middle and Late Ordovician, the sequence of strata of the Ordovician growth completely. The sequence of strata is unique, the Middle and Lower Ordovician is identical with that of the Tazhang low uplift,the Upper Ordovician is similar to that of the Tadong region. There are a lot of conodont in the Qaerbake Formation and Yijianfang Formation, they belong to three fossil zone:Pygouds anserinus, P.serrus and Eoplacognathus suecicus. The boundary of Upper and Middle Ordovician is place in 5 875 m. There is not any lacuna or unconformity. The Lianglitag Formation in the carbonate platform had a phase transformation to the mudstone and calcareous mudstone of 191 m in Gulong-1 well. It display a blank space reflection in the seismic section and is easily followed the trail in the landscape.