Chapter 11 (Part 3) Flashcards
Clastic
Loose rock fragments (clasts)
cemented together
Chemical
Minerals that crystallize directly from
water
Biochemical
Cemented shells of organisms
Organic
Carbon-rich remains of once living
organisms
Coarse rocks (Gravel)
Conglomerate
Breccia
Medium (Sand)
Sandstones
Fine (Mud)
Siltstone
Shale
Clastic (Detrital)
Weathering: disintegration
Erosion
Transportation
Deposition
Compaction
Cementation
Dissolved ions in fluids of pore
spaces precipitate out → cement
Lithification
Compaction + Cement
Clastic Rocks
Smooth rocks/ sometimes has other chunks of rocks in them.
Chemical Rocks
Shiny interesting texture
Metamorphic Rock
Rock that has transformed into a new rock due to physical and
chemical changes brought on by increased pressure and heat
Foliated
Repetitive layering in metamorphic rocks.
Non-foliated
Dont have lines in the rocks
What is the large-scale
driving force for the rock cycle?
Plate tectonics
Alfred Wegener
Theory of Continental Drift
Pangea
When the whole Earth was connected
Problems with Wegener’s Theory
He did not have a mechanism behind the drifting of continents.
Arthur Holmes
Continental drift is caused by convection currents in the mantel.
Radioactive decay causes the Earth’s interior to cause convection.
Bathymetry and Paleomagnetism
Led to the theory of plate tectonics
The lithosphere (outermost shell of Earth) is…
…composed of 13 or
more large rigid plates and numerous smaller ones
Continents are…
…old
Geologic activity is concentrated along the…
…boundaries between
plates
Ocean basins are…
…young
Hot spots form…
…where mantle plumes rise from the core-mantle boundary.
Plate boundaries
Divergent <–>
Convergent -><-
Transform (slides past)
What is a factor of volcanos happening?
Convection
Plume locations are stationary in the…
…mantle
