Geology final Flashcards
Understand the vastness of geologic time
Earth is 4.5 billion years old, human history is a small fraction of earths life.
Be able to utilize superposition and cross-cutting principles
older rock is on the bottom, anything that cuts a sequence is younger than the sequence.
dentify and understand three types of plate boundaries
Convergent, divergent, and transform. Convergent together and divergent away.
Know the characteristics of the lithosphere and asthenosphere
lithosphere is the upper layer made of crust asthenoshpere is underneath soft molten
Be able to explain how all three rock types are formed
Cooling of molten rock creates igneous rock. Combination of heat and pressure create metamorphic rocks and weathering plus erosion and deposition creates sedementary rocks.
Understand the cations, colors, SiO2 content, etc. of mafic, and felsic rocks
Felsic is light colored with more silica and has the cations K, Na, and Al. Mafic is dark colored with less silica contains the cations Ca, Mg, and Fe.
Understand the relationship between viscosity, SiO2, and explosivity
Magma that is high in silica is more viscosity and creat more explosivity
Identify igneous rocks by their chemistry (mafic/felsic) and texture (aphanitic/phaneritic)
Granite, Diorite and Gabbro all phaneritic. Rhyolite andesite and basalt are aphanetic. Granite and rhyolite are felsic, Diorite andesite are intermediate, and Gabbro and basalt are mafic.
Know the composition of oceanic and continental crust
Oceanic is composed of basalt and continental contains granite.
Understand the difference between weathering, erosion,
Weathering is the destructive process that changes the physical nature or chemistry of the rock. Erosion is the removal of weathered material.
Know the difference between mechanical and chemical weathering
Mechanical weathering is the breaking down of rock, chemical weathering involves a reaction decompostion of the mineral into something else.
Understand chemical weathering’s relationship with water
Water contains acid which is the main agent in chemical weathering.
Know the four products of weathering of minerals in Bowen’s series
Quartz, Iron Oxide, clay, and dissolved ions
Know the detrital grain sizes and their resulting sedimentary rocks
Gravel size makes breccia and conglomerate, Sand size makes sandstone, silt size makes siltstone, and clay size makes shale.
Know the compostion of limestone
Limestone can be easily dissolved by rainwater.
Understand rounding and grain size and how they change with distance of transport from source area
The farther we go the smaller and more round the rocks become.
Understand the differences (origin, textures, extent) between contact and regional metamorphism
Origin of contact metamorphism is heat from the magma body bakes the rock it touches, For regional tectonic forces squeeze rock and cause minerals to line up. Contact has non foliated textures while regional is foliated. Contact affects a much smaller area than regional.
Understand how gradient affects stream velocity
More steep more velocity
Understand the three ways a stream transports sediment
Disssolved load, Suspended load, and bedload
Relate downcutting, base level, graded streams, and lateral erosion (
Base level is the level which a stream cannot downcut under, generally streams with a high base level tend to be doing more downcutting than lateral erosion. Streams with low base level will have more lateral erosion than downcutting.
Understand what recurrence interval for a flood means
Gives a statistical probability of flooding in a given year.
Know the difference between porosity and permeability
Porosity is the amount of holes and permeability deals with how fast water can move through the rock.
Know and recognize on a diagram or sketch all groundwater zones (11). (the five zones: water table, confined aquifer, unconfined aquifer, saturated zone, unsaturated zone)
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Understand the formation of caves
Happens below the surface, when groundwater leaks through fractures in the limestone for the water to get in
Know the main landform-shaping agent in deserts
Water
Know & ID desert features of the Colorado Plateau
Canyons, Plateaus, Buttes, and Mesas.
Understand longshore current, longshore drift, and their causes
Longshore current refers to the water drift refers to the sand being moved by that water. Happens when the waves hit the shore at an angle.
Know the source and mineralogy of most beach sand and why
Rivers carry the sand from weatherd areas to the ocean. Mostly made up of quartz.
Know the different types of stress (and what they do to crust) and strain
Compressive, Tentional, and Sheer. Compressive stress squeezes and the crust becomes shorter and thicker. tentional stress makes the crust longer in the horizontal dimension and shorter vertically. Sheer stress does neither. Compressive for convergent, divergent is tentional, and transform is sheer. Reaction will either be elastic, brittle, or ducktile.
Understand strike and dip and be able to read them on a geologic map
Identify folds from descriptions AND on a geologic map
Dip reversal indicates a fold if fold is anticline then arrows point away from the fold. Sincline is indicated by the arrows pointing towards eachother.
estuary,
Drowned river mouth.
brackish,
mix of salt and fresh water.
barrier island
Ridge of sand paralleling the shoreline and extending above sea level.
dentify from a description AND diagram all types of faults discussed and hanging wall/footwall(15). (normal, reverse, left-lateral strike slip, right-lateral strike slip)
Top heavy is the footwall bottom heavy is the hanging wall. Normal fault the hanging wall moves down Tensional. Reverse fault is the result of compression stress hanging wall moves up. Both strike slip faults are sheer stress at transform boundaries.
Be able to relate a structure to the type of stress that formed it
Folds are the result of compressive stress, reverse faults are the result of compressive stress, normal faults are tensional stress and strike slip faults are sheer stress.
Understand what an unconformity is
A surface that represents a break in the geologic record, with the rock unit immediately above it being considerably younger than the rock beneath.
Know the 3 types of seismic waves and differences between them (16). P, S, surface
p waves are the fastest, s waves are the second fastest but can’t go through water, surface are the most damaging to the land.
Understand the difference between quake intensity and magnitude
Magnitude is the energy released by the earthquake, intensity is what it does to buildings and people.
Know the worldwide distribution and causes of earthquakes
Most occur at plate boundaries
Understand the accuracy of earthquake prediction
Not that good at prediction
Match metals to their common ore sources
Iron comes form hematite magnetite creates steel. Copper is from chalcopyrite and us used in electricity and brass. Aluminum comes from bauxite used in everything. Lead comes from galena, used in batteries. Zinc is found in sphalerite and us used to galvanize brass and steel. Silver is a byproduct of zinc mining, used mainly for jewelry and tableware. Gold is a natural element used for electronics, coins and jewelry.
Describe the three elements necessary for petroleum deposits
Exploitable petroleum resources require a carbon-rich sourcerock (often shale), a permeable reservoirrock (oft. sandstone), and a low-permeability traprock (oft. shale) to halt migration of petroleum to the surface
Explain possible causes of + and – magnetic (Fe) and gravity (mass) anomalies
Magnetic anomalies have to do with total iron and gravity deals with total mass.
Explain isostatic crustal responses to deposition and erosion
Sink as more weight is added and rise as weathering and erosion takes place.
Explain the significance of the P-wave and S-wave shadow zones.
P-wave shadow zone shows us the location of the core mantle boundary, the s-wave shows us that the core is liquid.
