01:460:100 Lecture Notes - Lecture 7: Silicate Minerals, Thermal Expansion, Weathering
11 Mar 2019
School
Department
Course
Professor
01:460:100 verified notes
7/14View all
Document Summary
Chapter 7 - pages of earth"s past: sedimentary rocks. Sediments - rock and mineral fragments, shells, mineral precipitates. Sedimentary cover - the veneer caps igneous and metamorphic basement. rocks. Sediment cover varies in thickness from 0 to 20 km. Thinner (or missing) where ig and meta rocks outcrop. Weathering - processes that break up rock to create sediment. Creates broken fragments or detritus. detrital fragments classified by size. Jointing - deep crustal rocks are hot and under high pressure. Chemical - decomposition by reaction with water. Saprolite. chemical weathering is virtually absent in deserts. Hydrolysis - water breaks cation bonds in silicate minerals. Oxidation - a reaction whereby a metal loses electrons. Hydration - absorption of water into a mineral structure. Minerals differ in their tendency to weather chemically. High t and p minerals tend to weather quickly at low t and p. low t and p minerals are more stable at earth"s surface.
