【摘要】 <正> 人们对事物本质的认识,往往从现象开始。我们对麻江古油藏的认识,是从对志留系含沥青砂岩的调研开始的。一贵州东部的麻江、都匀、丹寨、凯里一带,在志留系翁项群第二段(S_1-2wn²)中,广泛而稳定地分布着一套形象十分特殊的“黑砂岩”。细察之,其黑色并非导源于砂粒本身,实因其粒间充填物黑色所致。此填充物为何?是否石油的变异产物?其历史演变怎更多还原

【Abstract】 Recently,the black sandstone in the 2nd member of Wengxiang group(S_1-2wn²)in Majiang,Duyun,Dangzhai and Kaili regions in eastern Gui-zhou was studied by detailed field survey and a lot of laboratory tests,andwas discovered no other than bituminous sandstone.The bitumen,with whichthe pore spaces between sand grains are filled,is a variation of petroleum.As for the distribution of the bitumen,it is regularly related to the Majiangpaleoanticline formed in Late Caledonian movement.It could only be found insandstone of the 2nd member of wengxiang group located higher than -500mcontour of this paleoanticline;otherwise,no bitumen could be found at all.eanwhile,as these sandstones had gradually turned into silty limestone alongthe western slope of the paleoanticline,no bitumen would be found though theylocated above -500m couuter.Thus,the bituminous sandstone could be consideredas a great oil pool during Silurian period,the reserve of it was more than abillion tons,whereas the reservoir type was a strucl-lithologic complex,nd its oil-water boundary was the -500m contour.In Duyun movement of final phase of Silurian,the pool was seriously des-troied as the anticline was uplifted and denuded,and large amounts of oil andgas escaped,the remnants then were only dense oil and bitumen.During In-o-China and Yanshan movements,the paleoanticline was thoroughly disintegrated,even the dense oil solidified.The remnant reserve of bitumen is now only around 30 million tons,scattering in local areas of Duyun and Yudong synclinesas well as Wangsi anticline.mall amount of bitumen could be found in cracks and holes in carbonate rocksof Lower Ordovician Honghuayuan group,which is connected with the above-said Silurian reservoir,thus this is considered only part of the Majaing paleopool.Based on our research,the source rock of Majiang paleopool is bituminousshale of Lower Cambrian.The crude oil of this paleopool is not the same as thatin Dawan group of Lower Ordovician in Kaili area by δc¹⁴ and other data,ex-actly,they belon ferent series.更多还原