Chapter 1 + 2 Flashcards
Name the earths layers and what they are mostly made out of
Core- iron
Mantle- igneous rock (peridotite)
Asthenosphere- surrounds the lower mantle. Moves like plastic and generates magma. Some rises to the surface cause it’s less dense
Lithosphere- upper mantle. Where plate techtonics are.
What is the plate tectonic theory?
Large segments of earths lithosphere move relative to one another
Zones of volcanic and eatherquakes mark plate boundaries
Provides an explanation to unrelated phenomena
How are the rock cycle and plate tectonics related?
- plate movement: driving mechanism of the rock cycle
- plate interaction helps determine which of the three rocks will form
What is the theory of organic evolution?
Everything is related; descended with modifications
Fossils- provide evidence for evolution and life before humans
What is geologic time?
Humans perspective time is short- earth goes through long cycles
Geologic scale divides time into hierarchy of increasingly shorter time intervals
What is uniformitarianism
Present- day processes have operated throughout geologic time
“The present is the key to the past”
Kamloops is an example (use to me a glacier lake)
What are some evidence of plate tectonics?
Continents fit together like puzzles pieces
Similar rock sequences and mountain ranges
Glacial evidence
Fossils
What are 10 features of the sea floor
Continental shelf Continental slope Abyssal plain Ocean ridge Submarine hydrothermal vent Ocean trench Seamounts Guyots Aseismic ridge
What are the continental margins?
Active- leading edge of continental plate where lithosphere is subducted. Narrow continental shelf
Passive- within a plate. Lack of volcanic and seismic activity
How did scientist figure out magnetic field has changed over years?
Looking at continental lava flows: age dating, determined the orientation of the remnant magnetism
Deep sea drilling at the mid ocean ridge
What are the three types of plate boundaries and what do they create?
Divergent- plates are spreading < > Crust is extending and thin C-C rift valleys (East African Rift Valley) O-O mid ocean ridge
Convergent- plates colliding > <
C-C mountains
O-C island arcs, ocean trenches
O-O mountains, trenches
Transform- plates sliding passed each other
Changes the motion of plates
C-C crustal deformation
O-O offset mid ocean ridge
What is a Hot spot?
Within a plate where a stanionary column of magma has formed a volcano
Explains some geologic activity occurring in plates
How do scientists know plate movement?
Dating magnetic anomalies on the sea floor
Satellite laser ranging techniques
What are the driving mechanisms of plate tectonics
Convection heat system: radioactive decay in earths interior; additional heat comes from the core
Slab pull: descending lithosphere pulls the plate along
Ridge-push: rising magma and gravity push the lithosphere out from the mid-ocean ridge
