Section 2 Flashcards
What is the definition of Plate Tectonics?
A scientific theory explaining the movement of Earth’s lithosphere, divided into tectonic plates that float on the semi-fluid asthenosphere beneath.
What occurs at convergent boundaries?
Plates collide, forming mountains or subduction zones.
What happens at divergent boundaries?
Plates move apart, creating mid-ocean ridges or rift valleys.
What is the result of transform boundaries?
Plates slide past each other, causing earthquakes.
What are three pieces of evidence supporting Plate Tectonics?
- Fossil distribution
- Matching geological formations across continents
- Seafloor spreading
What are faults?
Breaks in Earth’s crust where movement has occurred.
What causes normal faults?
Tensional stress, where the hanging wall moves down.
What are reverse faults caused by?
Compressional stress, where the hanging wall moves up.
What characterizes strike-slip faults?
Horizontal movement.
What are folds in geology?
Bends in rock layers due to compressional forces.
Define anticlines.
Upward arching folds.
Define synclines.
Downward troughs.
What are monoclines?
A single bend in otherwise horizontal layers.
What is Bowen’s Reaction Series?
A model describing the sequence of mineral crystallization from magma as it cools.
What happens in the discontinuous branch of Bowen’s Reaction Series?
Minerals change composition as magma cools.
What is an example of a mineral in the discontinuous branch?
Olivine → pyroxene → amphibole → biotite.
What characterizes the continuous branch of Bowen’s Reaction Series?
Plagioclase feldspar evolves from calcium-rich to sodium-rich.
Why is Bowen’s Reaction Series important?
Explains rock diversity and how minerals relate to igneous rock formation.
What is a crater in volcanic terms?
Depression at the summit of a volcano.
What is a caldera?
Larger depression formed when a volcano collapses.
What is a vent in the context of volcanoes?
Opening through which lava and gases escape.
What are lava flows?
Streams of molten rock.
What are lava plateaus?
Extensive flat areas covered by lava.
How are volcanic domes formed?
By viscous lava piling up near the vent.
