undifferentiated rock units

Paleontology and geology

Few Cretaceous sedimentary rocks can be found in Nevada. They occur only in scattered pockets in the eastern part of the state, not shown on this map. A chain of volcanic islands, which later formed the granitic Sierra Nevada Mountains of today, comprised the western perimeter of the state. Scattered twigs thought to be from Sequoia trees are reported from Eureka County (central Nevada). Otherwise, virtually no fossils of this age are known from the state.