ObjectivesDescribe the path of minerals through the rock cycle.Compare and contrast igneous, sedimentary, andmetamorphic rocks.Differentiate between weathering and erosion.
The Rock CycleWhat was the name ofthe cycle that we talkedabout the other day? Tectonic Cycle Remind me what that is
The Rock CycleRock Cycle: Constantformation anddestruction of rock Slowest of all of Earth’s cycles
The Rock CycleIf you had to define theterm “rock” how wouldyou do it?Rocks are composed ofmineralsSo the question is, whatis a mineral?
The Rock CycleMineral Characteristics Solid Uniform crystalline structure Form under specific temperature and pressure Generally compounds
The Rock CycleWe are going to movethrough the rock cycleusing the formation ofeach of the 3 majortypes of rock.Each type of rockrepresents a step in thecycle.Does anyone known thethree types of rock?
The Rock CycleIgneous First step in the cycle Forms from cooled magma Classified as basaltic or granite and intrusive or extrusive
The Rock CycleIgneous Basaltic - dark colored, high concentration of dense elements, forms oceanic crust Granite - light color, lighter elements, forms continental crust
The Rock CycleIgneous Intrusive - magma cools underground. Slow cooling leads to large crystals and coarse texture Extrusive - cools quickly on the surface. Quick cooling leads to small crystals and a smooth texture
The Rock CycleOnce rocks are on thesurface, what are thesubjected to? The elementsWhat do you think theelements do to therocks? Break them down
The Rock CycleWeathering vs. Erosion Weathering - the breakdown of a rock Erosion - the transport of sediments that result from weathering
The Rock CycleWeathering Two types Physical - physically breaks down the rock No chemical change Chemical - chemically changes the rock composition
The Rock CycleWeathering Physical Weathering How might a rock be broken down physically?
The Rock CycleWeathering Freeze/thaw Ice wedging Abrasion Biological action
The Rock CycleChemical Chemical reactions lead to degradation Can be sped up by physical weathering Primary minerals react to form secondary minerals
The Rock CycleChemical What could lead to chemical weathering? Water dissolving minerals Lichen dissolving rock Acid Precipitation
The Rock CycleErosion The transport of sediments produced by weathering Accomplished by Wind Water Ice
The Rock CycleErosion When the erosive force stops deposition occurs Deposition - accumulation of transported material Human activities can greatly enhance erosion
The Rock CycleSedimentary rock What is the term for the accumulation of sediment? As sediment collects, what do you think happens to the bottom of the pile?
The Rock CycleSedimentary rock Lower layers of a sediment pile are subject to tremendous pressure Pressure causes grains to cement together Forms sedimentary rock
The Rock CycleSedimentary rock Generally has a layered appearance Why?
The Rock CycleMetamorphic Rock Forms when rock is exposed to extreme heat and pressure Where might this occur?
The Rock CycleMetamorphic Rock Continental boundaries Areas with a large load of overlaying rock layers Exp. marble and slate Often used as building materials
The Rock CycleWhy would sedimentaryrock be the only type ofrock that containsfossils?Why would metamorphicrock be good forbuilding?