GEOL 003 Lecture Notes - Lecture 9: Honeycomb Weathering, Silicate Minerals, Crystal Growth
Document Summary
Disintegration of rocks and minerals into smaller pieces. Decrease in overlying pressure (load) causes underlying rock to expand upward. Leads to pressure release cracks in the exposed rock. Water enters cracks in surface materials (rocks,roads) Temperature drop causes water to freeze, expand and force the cracks to expand. Process repeats when ice melts, water finds new crack, freezes again and expands the cracks. Growth of salt crystals in small rock openings. A result of salt crystal growth on surface of rock, expanding the size of the hollows. Physical weathering breaks rocks into smaller pieces increasing the surface area over which weathering can occur. The decomposition of rock due to the chemical breakdown of minerals is called chemical weathering. Minerals in a rock are dissolved by water. Example: acid rain removes detail of a statue. Hydrogen ions in water replace other ions in silicate minerals.
