Weathering: involves the physical breakdown and chemical alterations of rock at or near earths surface, with no transportation, two types: Physical forces breaking rocks into smaller pieces. Chemical transformation of rock into new compounds: both types work simultaneously and reinforce each other. Mechanical weathering increases surface area: surface controlled processes. As mechanical weathering breaks rock into smaller pieces, more surface area is exposed to chemical weathering. Water works its way into cracks in rocks and the freezing enlarges the cracks in the rocks. Lenses of ice grow larger as they attract liquid water from surrounding areas. Can wedge out rock material and split rocks: salt crystal growth. Sea spray or salty groundwater penetrates crevices and pore spaces in rocks. As the water evaporates, salt crystals form and enlarge the crevices: sheeting/unloading. Large masses of igneous rock are exposed by erosion and concentric slabs break loose.