The farmers found the alluvial deposits at the mouth of the river very fertile.

农民发现这条河口底下的沉积物很肥沃。

Four alluvial deposits distributing along Yuanjiang river and the diamondiferous rocks that supply diamonds to these placer deposits have striking properties of varied sources and multi-phases.

沅水流4个石砂矿床，给石砂矿的石岩体具多期多源特点。

Mainly developed are fan - delta, deep lake turbidite and calcirudite deposit, and also alluvial fan deposit in early period.

各时期形成的砂岩和粒屑灰岩储集体,为油气储集提了有利的场所。