S THROUGH Z: •
Salt – this is any ionic compound that dissolves in water. Calcium salts and sodium salts are commonly discussed in geology.
•
Saltation – this is when sand grains bounce along because of the activities of flowing water or windy conditions.
•
Sand – these are tiny particles up to 2 mm in diameter that are made from quartz and resistant to most chemical breakdown techniques.
•
Sandstone – this is sedimentary rock that has medium grains within its structure and that consists of cemented sand grains.
•
Schist – this is metamorphic rock that has shiny mica in it that is arranged in a foliated way.
•
Sea-stack – this is a tall pillar of rock you can see coming up out of the sea and worn into a pillar by the action of waves eroding the rock.
•
Sediment – this is any type of material that layers out due to the action of standing water and gravity. This can be anything – sand, organic material, shells, mud, or pebbles. Sediment may or may not become rock.
•
Sedimentary rock – are formed on or near the Earth's surface from the compression of ocean sediments or other processes.
•
Shale – this is a rock that was compressed to make dark-colored, grayish sedimentary rock. Expect to see fine, microscopic grains.
•
Sill – this is an intrusion or influx of igneous rock that has seeped in along the planes of other rock layers.
•
Slate – this is metamorphic rock made through compression of mudstone.
•
Soil creep – this is mass movement that happens gradually due to gravity on steeper mountains or hillsides.
•
Strata – these are any layers you see within rock itself, usually made by sediment of some kind. 10
