Four isolate barrier beds occurened usually in boundary surface of each internal architecture unit in channel sandbody, i. e. find bed, muddy pebble bed, plant clasts bed and diagenic bed.

在河道砂构成的不同层次实界面，通常存在着4种隔挡层，即细隔挡层、泥砾隔挡层、植碎屑隔挡层和成岩隔挡层。