BASAL CONGLOMERATE MEMBER.

This member has only local development in Fossil Basin. Where found, it

is a lenticular conglomerate with pebbles and cobbles of buff and tan

sandstone from the Nugget Sandstone and limestone fragments from the

Thaynes and Twin Creek formations.

The basal conglomerate is essentially a channel fill in ancient stream

beds cut into Mesozoic rocks.

The Geological History of Fossil Butte National Monument and Fossil Basin · 第 12 / 50 题