Exam #1 for Geology Study Guide
Jakob Valleroy
Spheres: Atmosphere, Biosphere, Hydrosphere (cryosphere), Geosphere (crust & upper most
mantle)
• The universe is older than the solar system
• The universe originated as a result of the big bang
• Mars was the planet to exhibit evidence of free water in the past
Earth’s layers:
Core:
• Inner: solid, temperature higher, pressure higher
• Outer: liquid, convecting, magnetic poles
Crust:
• Silicates –> feldspar to clay
• Quartz
• Carbonates (Co3)
• Halides (Na)
2 types of crust:
• Ocean: thinner, more dense
• Continental: thicker, less dense
Lithosphere: upper most mantle, rigid, elastic
Asthenosphere: ductile, plastic, convects
Mantle: partially molten, made of oxides (O) and silicates (SiO4), any mineral that ends in O is
an oxide. (asthenosphere)
• SiO4- olivine
• FeO- magnetite
3 types of plate boundaries
• Diverging: generate new crust all the time, 2 plates move away from other (cause
volcanic activity and shallow earthquakes)
• Converging: gets rid of all crust, 2 plates moving toward each other, one plate “subducts”
beneath the other (variety of earthquakes, line of volcanoes on the overriding plate)
• Transform: plates slide by each other horizontally (shallow earthquakes with little to no
volcanic activity)
Plate tectonic theory
• Seafloor spreading: every young in the center, old close to continents, generating new
rock and ages at the edges of continents, comes up and spreads apart, radiometric
isotopes
• Continental drift: continents move around, puzzle fit, fossil evidence (same organisms on
widely separated), rock sequences (from super continent “Gondwana”), glacial evidence.
Lithospheric plates: crust and uppermost mantle
• Passive: no tectonic activity, but there is erosion and deposition
• Active: tectonic activity occurs
Types of plate boundaries:
Type: Divergent:
• Oceanic (telegraphic high) -> Example: Mid-Atlantic Ridge (M-AR) / East Pacific Rise
(EPR) -> Landforms: Mid oceanic ridge with axial rift valley –> Volcanism: Basalt
• Continental (telegraphic low) -> Example: East African Rift Valley -> Landforms: Rift
valley (basin filling up with water) –> Volcanism: Basalt & Rhyolite, NO andesite
Type: Convergent