geology part 2 rev Flashcards
What is subduction?
Subduction is the process where one tectonic plate sinks beneath another plate at a convergent boundary. Only caused from oceanic to continental plate.
What is convection?
convection refers to the movement of the Earth’s mantle material caused by variations in temperature and density. This movement plays a significant role in driving the motion of tectonic plates
Who is Alfred Wegener?
Alfred Wegener was a German meteorologist and geophysicist who proposed the theory of continental drift
What is the theory of continental drift?
The continents move slowly over Earth’s surface/Where continents were once together, but drifted away
What is some evidence that supports continental drift?
- Continents fit together
- fossils of organisms and living things were scattered all around the world of continents, with no explanation of how they got there
- Similar geological features; age of rocks, type of rocks, and landforms connect along borders
- Glacial scratches along rocks across continent aligned
What is the supercontinent in this test called?
Pangaea
What is seafloor spreading? / What is the theory of seafloor spreading?
A process in which new crust was being formed at the ridges, forcing continents apart
Who proposed seafloor spreading?
Harry Hess
Who is Harry Hess?
Harry Hess was an American geologist and a pioneer in the theory of seafloor spreading.
What is a lithosphere?
The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the uppermost part of the mantle. It is divided into tecotnoic plates which contribute to the movement
What is the theory of tectonic plates?
states that the Earth’s lithosphere is divided into several large and small plates that float and move slowly overtime on the semi-fluid asthenosphere below.
What is asthenosphere?
The asthenosphere is a semi-fluid layer of the Earth’s upper mantle located beneath the lithosphere. It is composed of partially molten rock
What is some evidence of seafloor spreading?
- Magnetic Striping
- Age of seafloor (layers)
- Sediment thickness (layers)
What is magnetic striping?
refers to the alternating patterns of magnetic polarity recorded in rocks on the ocean floor
What are all the types of boundary interactions?
Transform, converge, and diverge
Who proposed the theory of tectonic plates?
Harry Hess, He proposed that the plates were forced to move due to convection currents in the mantle.
What are some pieces of evidence that support the theory of tectonic plates?
Activity of volcanoes, Earthquakes, and the heat along boundaries of plates.
How does volcanoes support the theory of tectonic plates?
Volcanoes are usually caused by subduction, and subduction is only caused by the movement of plates converging one another, whilst one plate slips underneath to melt, building pressure to eventually cause a volcano, therefore supports this theory
How does earthquakes support the theory of tectonic plates?
Earthquakes can only occur when the immense build of pressure or energy is released from contacting plates, therefore supporting this theory
How does the distribution of heat along boundaries support the theory of tectonic plates?
Gaps between plates (diverge) can release magma, causing heat, as well as the friction caused from contact plates putting force on one another can also cause this heat
What landforms occur between the convergence of a O & C plate?
Volcanoes, volcanic arc, trenches and fold mountains
What landforms occur between the convergence of a O & O plate?
Island arcs, volcanoes caused by subduction of faster moving plate, and trenches
What landforms occur between the convergence of a C & C plate?
mountains
What landforms occur between the divergence of a O & O plate?
Mid ocean ridge/ridge
