3Weathering in the Rock Cycle AndPressureCementationWeathering/ErosionSedimentary RocksSedimentWeathering/ErosionHeatErosionPressureWeatheringHeat and PressureMetamorphic RocksIgneousRocksHeatCoolingMagma
4Three Dynamic Processes of Breaking and Removing rock Weathering - the disintegration and decomposition of rock at or near the surfaceErosionMass Wasting
5Types of Weathering Mechanical – physical breakdown of rocks. Chemical – decomposition of rocks by chemical reactions.
17Thermal expansionrepeated daily heating and cooling of rock;heat causes expansion; cooling causes contraction.
18Chemical Weathering Chemical alteration of minerals. Results in new minerals and ions in solution.Water and acid are essential.
19Types of Chemical Weathering Hydrolysis - any reaction in which water participates.Ion Exchange – H+ replaces other cations.Dissolution - mineral completely dissolves, leaving only ions in solution.Oxidation - reaction in which elements gain or lose electrons (example: rust).
20Carbon dioxide reacts with water to form carbonic acid (Equation 1) Carbon dioxide reacts with water to form carbonic acid (Equation 1). Carbonic acid then dissociates to give the hydrogen ion (H+) and the hydrogen carbonate ion (HCO3-) (Equation 2). The ability of H2CO3 to deliver H+ is what classifies this molecule as an acid, thus lowering the pH of a solution.