Subject
Geology
Geology, Stratigraphic
109
Groundwater
30
Paleontology
24
Texas
16
Edwards Aquifer (Tex.)
15
Mines and mineral resources
15
Petrology
14
Water-supply
14
Petroleum
12
Aquifers
11
Hydrogeology
11
Atmospheric radioactivity
9
Geology, Economic
9
Petroleum Geology
7
Radioactive waste disposal in the ground
6
Uranium ores
6
Hydrography
5
National parks and reserves
5
Trinity Aquifer (Tex.)
5
Coal
4
Mercury mines and mining
4
Natural gas
4
Paleobotany
4
Roads
4
Gold mines and mining
3
Igneous rocks
3
Iron ores
3
Limestone
3
Mineralogy
3
Oil fields
3
Rocks Analysis
3
Botany
2
Coal mines and mining
2
Corals, Fossil
2
Dockum Group
2
Environmental monitoring
2
Facies (Geology)
2
Fluorspar
2
Geological mapping
2
Geology Maps
2
Geophysics
2
Guadalupe Mountains National Park (Tex.)
2
Historic sites
2
Hydrology
2
Mercury ores
2
Mollusks, Fossil
2
Ore deposits
2
Palo Duro State Park (Tex.)
2
Potash
2
more ...