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
