- stratification
- stratigraphic trap
- stratosphere
- stratospheric
- stratum
- structural strap
- subduction zone
- subsurface conditions
- subduction
- suite
- superstrata
- superstratum
- surface demarcation
- surface-water
- syenitic
- synclinal
- syncline
- syngenesis
- tali
- target
- tectonic
- tectonics
- tectogenesis
- tectonic process
- syenite
- table
- talus
- tephrite
- terrain
- terrace
- tertiary
- till
- thread
- threw
- thrown
- throw
- tract
- transmutation theory
- transgression
- trilobite
- troposphere
- tundra
- trias
- triassic
- tropic
- uncharted
- unconformity
- unconformity trap
- ullmannite
- uncovering
- undercompacted
- undercompaction
- undercompacted zone
- understratum
- understrapper
- updip
- upcast
- upthrow
- uplift
- upper
- upraised
- upthrust
- vane
- variable
- veinstone
- vesicle
- vent
- vesicular
- vesiculation
- wall
- wash
- weathering
- well
- work
- wrinkle
- xenomorphic
- zoic
- zone
- zoolite