Geology sol review Chapters 4 - 12

Ch. 4 Resources Difference between renewable and nonrenewable Hydroelectric Solar Wind Biomass Nonrenewable Fossil fuels (coal, oil, natural gas) Nuclear Minerals Advantages and disadvantages of resources Uses of resources

Ch. 5 Weathering and Erosion Difference between mechanical and chemical weathering Examples of weathering Mechanical – unloading or exfoliation and frost wedging Chemical – hydrolysis, carbonation, oxidation Factors that affect weathering (surface area, climate, temperature, moisture) Water is the most important agent of chemical weathering and erosion A mass movement is any erosion event where large amounts of rock are moved due to gravity Minerals that form first at the highest temperatures will weather the fastest Minerals the form last at the lowest temperatures will weather the slowest

Soil Profile

Chapter 6 Rivers and groundwater Factors that affect stream flow: Gradient – The steeper the slope the faster the flow The larger, smoother, and straighter the channel the faster the flow Discharge – The amount of water in the stream The greater the discharge, the faster the flow

The material carried by the stream is the load Dissolved Suspended Bed (greatest impact on erosion)

Deposition of a river Alluvial fans form on land where the velocity of a river decreases Deltas form at the mouth of a river where it meets a larger body of water

Watersheds of Virginia

Porosity – amount of pore space available in rock Permeability – movement of water through rock Rocks such as sandstone have high permeability Permeable rock layers are called aquifers Rocks such as limestone and shale have low permeability

Review groundwater pollution and wells Zones of Groundwater Review groundwater pollution and wells

Karst Topography Any area that has limestone bedrock Features include caverns, sinkholes, stalactites and stalagmites

Ch. 8 Earthquakes Know the parts of an earthquake Information is needed from 3 seismograph stations in order to find the epicenter Earthquakes occur along faults where movement occurs. Magnitude – energy released Intensity – damage Types of seismic waves: p waves – primary s waves – secondary love and rayleigh waves – surface, most damage

Evidence for continental drift Puzzle like shape Ch. 9 Plate tectonics Evidence for continental drift Puzzle like shape Similar rock types, fossils, and mountain ranges on different continents

Seafloor spreading Mechanism that causes continental drift Spreading occurs along the mid ocean ridge As you move away from the ridge, the age of the ocean floor increases (the youngest rock is close to the ridge) The force that drives seafloor spreading is convection

Plate characteristics Oceanic crust is more dense than continental crust The lithosphere contains both the continental and oceanic crust and the upper mantle The asthenosphere is found beneath the lithosphere and is found in the mantle Convection occurs in the mantle The most dense layer of the earth is the core

Features of plate boundaries Convergent Mountains, trenches, subduction zones, island arcs, continental volcanic arcs Divergent Mid ocean ridges, rift valleys Transform Most earthquakes

Ch. 10 volcanic activity Types of magma Types of volcanoes Felsic (mostly silica, many trapped gases, explosive, continental) Mafic (mostly magnesium and iron, few trapped gases, quiet eruptions, oceanic) Types of volcanoes Island (shield) and continental arcs (stratovolcanoes) - convergent plate boundaries Fissure – form at mid ocean ridge Hot spot – form over a mantle plume of magma; volcanoes form in a chain because the plate moves but the plume doesn’t; form on the ocean floor

Ch. 11 mountain building Most of the mountains in our region are folded mountains The Appalachian mountains are the oldest mountain system in the US Our mountains have undergone a large amount of weathering and erosion

Folds Faults convergent divergent transform

Ch. 12 Relative and absolute dating Relative dating determines the sequence of events, it does not give age Law of superposition – oldest rocks are on the bottom, youngest rocks are on the top Law of crosscutting – faults and intrusions are always younger than the rocks they cut across Unconformities – erosional features in a rock sequence where erosion has removed part of the rock record

Absolute dating provided actual ages of rock Fossils Radiometric dating (using uranium to determine the age of rock) Compare the amount of parent and daughter isotopes to determine the number of half lives Carbon dating (using carbon to determine the age of fossils)