Abstract:

In recent years,the writers have obtained a lot of foraminiferal fossils from the late Early Carboniferous(Datang Stage)in the Liangyuan-Shaoyang region of central Hunan Province and carried out a detailed stuty on them.Based on their character,3 foraminiferal assemblage zones can be established in an ascenting order:1.Dainella gumbeica-Plectogyra posneri assemblage zone;2.Eodiscus-Lituotubella glomospiroides assemblage zone;3.Endothyranopsis crassus-Archaediscus krestovnikovi assemblage zone.Among them,the,Zimenqiao Group is the representative deposit of Endothyranopsis crassus-Archaediscus krestovnikovi assemblage zone;the other two zones represent respectively the deposits of upper or lower part of Shidengzi Group(see fig.1).The foraminiferal of the Datang Stage shows obviously the aspect of the later Early Garboniferous System and is similar to that of the Visean Stage in Moscow Basin of Soviet Union.It should be stressed that the Shidengzi Group is not only a comparatively favorable reservior rocks,but also a fine source rocks.In addition,the coalbearing beds of Ceshui Group and the gypsiferous beds of Zimenqioa Group are excellent covers.Therefore,in comparison with the other conditions as concerning the combination of source-reservior-cap rocks in present region,the Datang Stage should be a considerably favorable oil & gas bearing beds.