The river is eating away at the softer nonmarine sandstone, with the harder rock forming the falls themselves.
12.
Estimates of the numbers of nonmarine molluscs vary widely, partly because many regions have not been thoroughly surveyed.
13.
However, in 2004 the IUCN Red List of Threatened Species included nearly 2, 000 endangered nonmarine molluscs.
14.
The "'Battle Formation "'is a stratigraphic marker in the nonmarine Upper Cretaceous sequence.
15.
These coalbeds are part of the Skookumchuck Rock Formation, which is composed of nearshore marine and nonmarine sedimentary rocks.
16.
About 42 % of recorded extinctions since the year 1500 are of molluscs, consisting almost entirely of nonmarine species.
17.
The ML pipes are hosted within the nonmarine sedimentary rocks of the Wapiti Formation and were erupted onto an inland alluvial plain.
18.
The nonmarine rock is primarily sandstone, with some coal, shale, " black " or carbonaceous shale, and siltstone.
19.
The nonmarine layers are characterized by gastropods like Australorbis, Lymnaea / Galba and Viviparus and ostracods like Gandona, Cypridopsis and Moenocypris.
20.
The Dawson Arkose contains plant remains and other nonmarine fossils, and hosts aquifers that are important sources of water for the area.
