| 1. | The feldspar of the reservoir sandstone in the study area consists of a higher percentage of na feldspar that of k . feldspar . the sandstone is composed of certain little rock fragments such as pyrite , mica , siltstone , mudstone , chert , and volcanic fragments 砂岩内长石由钠长石与钾长石组成,以钠长石为主;岩屑由黄铁矿、云母、粉砂质、泥质、燧石与火山岩屑构成。 |