GEO 101 Lecture Notes - Lecture 7: Geologic Map, Cross-Bedding, Clay Minerals

• School: University of Alabama
• Department: Geological Sciences
• Course: GEO 101
• Professor: William Lambert

Document Summary

Sandstone: biochemical- formed from material (such as shells) produced by living organisms (ex. Coquina: organic- formed from carbon-rich relicts of plants (ex. Coal: chemical- formed from minerals that precipitate directly from water solutions (ex. Limestone: formation of clastic sedimentary rocks, weathering- the process that break up and corrode solid rock, eventually transforming them into sediment. Physical (mechanical) weathering- the process in which intact rock breaks into smaller grains or chunks (chemistry of rock does not change) Frost wedging- expansion of water in cracks by freezing, wedging the rock apart. Unloading (pressure release)- as pressure is decreases due to removal of overlying rock by erosion, igneous/metamorphic rock expands and fractures in large sheet-like layers. Thermal expansion and contraction- rapid heating and cooling of a rock"s surface, resulti(cid:374)g i(cid:374) (cid:373)ore rapid e(cid:454)pa(cid:374)sio(cid:374) a(cid:374)d co(cid:374)tractio(cid:374) of the rock surface than the rock interior. Biological activity- the cracking and expansion of rocks as a result of plant growth or animal activity.