四川广元──陕西宁强间下志留统生物礁

川西北广元-陕西宁强间下志留统巨厚的暗色泥岩地层中赋存有数以百计的生物礁，包括堤礁、点礁、堤状点礁群、生物岩丘、灰泥丘、层状岩丘，出露好，大小不一。礁是在浅水陆棚泥岩相的基础上发育起来的.造礁生物主要为横板珊瑚属的链珊瑚和蜂窝珊瑚及泡孔目的皮壳状、半球状苔藓虫。礁发育的基底主要为泥基质疙瘩状灰岩，也可以是生屑滩、近基风暴岩和淹没的潮坪层纹石灰岩。礁的衰亡以淹死型为主，少数为旱死型。在广元河湾场地区的河深１井钻遇礁组合５３.５５ｍ，中途测试有气浸显示、川南井下亦钻遇生物灰岩、生清灰岩（可能即为生物礁），见沥青充填裂隙、晶洞。包绕礁体的暗色泥岩有机炭丰度高。因之，志留系生物礁有希望成为四川盆地潜在的油气勘探目的层。

Organic Reef in Lower Silurian. Guangyuan.Sichuan to Ninggiang. Shanxi

Between Guangyuan. Sichuan to NingqiAng. Shaanal province, Within giant-thick dead color mudstones of lower Silurinn there are hundred of reefs developed, including hairier reef, Patch reef, harrier-like batch reefs, biohorm, triemud mound and bed-rock mound. All of them are out croped well and a gteat disparity in size. The reefs developed on the bsses of the mudrock fscies of the shallower shelf. The reef-building orgnnisin are mainly Halysites. Favosites, subalveotella,paleaofavosites, and clathrodictyon, Rosenella. The basesment rock on which reefs glowed is mainly mudbho-knollenakalk and some are on the biocfast hank, the proximal tempestites and sumerged tidal flat Stratifera limestones. Many of the reefs declimed and fell because of drow and a few of them died for drought.The reef is over 50 meters thick in the Hoshen 1 well and Ho 15 well in Guangyuan. NOrthwest Sichuan, and a litter po was gotten in it. Also, the reef was found in many wells in the southern Sichuan. In addition, the reefs is distributed over the eastern Sichuan, NOrthern Guishou and weStern Hebui, the character of reef Complex is shoilar to that of the studied area. BitUmen filling crack and vug is often found. The organic carbon content in dead colon mudstone which wraped up the reefs is high. T'here for. It is hope for the reef of the lower Silurian to be the exploration bojective formation in the Sichuan basin.