Subject
Geology, Stratigraphic
21
Borings
16
Formations (Geology)
16
Powder River Basin (Wyo. and Mont.)
10
Oil well logging, Electric
8
Geophysical well logging
5
Petrology
5
Water quality
5
Pentagon Mountain (Mont.)
2
Lithofacies
1
Paleogeography
1
Paleontology
1
Paleontology, Stratigraphic
1
Rocks
1
Stratigraphic correlation
1