GLG 141 Parks and Plates Pt. 1

lithospheric plates

consist of crust, upper mantle, they are the moving plates on the surface

Soft-rigid lithosphere

the plates are the lithospheric broken chunks that move in response to forces

oceanic crust has more

iron and magnesium

continental crust has more

silica

lithosphere crust is made of two types of

igneous rocks

igneous rocks form from

the cooling of magma

earths first crust was formed after

the molten surface of the earth cooled

what two igneous rocks make up lithosphere crust

oceanic basalt, continental granite

the asthenosphere is below the

upper mantle

upper mantle is thicker under the

continents (continental crust)

upper mantle is thinner under the

oceans (basalt or oceanic crust)

characteristics of the aesthenosphere

soft, able to flow, solid elastic

the type of crust and type of boundary dictate

the type of geology that we observe at the surface

most earthquake activity aligns along

plate boundaries

geology that indicates plate movement (where lithospheric plates are)

mountains, trenches, volcanoes, land disturbance

75% of the worlds active volcanoes are in the

ring of fire

the ring of fire

a long chain of volcanoes and other tectonically active structures that surround the pacific ocean

90% of the most powerful volcanic eruptions and 81% of the world largest earthquakes occurred along the

ring of fire

Alfred Wagner first proposed

the idea of continental drift

Evidence of continental drift

climatic belts, fossils, matching geologic units, mapping the sea floor

climatic belts

glacial deposits that would fit together if continents were put back together

matching geologic units

distinctive belts of rocks such as mountains found all over the world, the same mountains in separate continents

distribution of fossils

the same species can be found on different continents

mapping the sea floor

subduction areas