Glossary Flashcards
Asthenosphere
A layer of mantle below the lithosphere.
Basalt
Dark fine-grained igneous rock formed from the rapid cooling of low-viscosity lava, rich in magnesium and iron.
Borehole
A deep narrow hole drilled down into the ground to extract, for example, oil, gas, water, or samples of rock.
core (inner)
hot dense ball of mostly iron.
Core (outer)
Third layer of the earth and the only liquid layer, mainly made up of the metals iron and nickel.
Crust (continental)
Layer of granitic, sedimentary, and metamorphic rocks, which form the continents and the areas of shallow seabed close to their shores.
Dolerite
Fine-to-medium-grained, dark grey to black intrusive igneous rock. extremely hard and tough.
Gabbro
igneous rock formed in the slow cooling of magnesium rich and iron rich magma deep beneath the earths surface.
Gutenberg Discon.
Marks the boundary between the mantle and core.
Granite
Coarse-grained intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase.
Lehmann discon.
In between the inner and outer core of the earth.
Lithosphere
The upper rigid layer of the crust and upper mantle.
Longitudinal wave
Waves were the displacement of the medium is in the same direction as the direction of the travelling wave.
Low velocity zone
Characterised by low seismic velocities
mantle
Mostly solid bulk of earths interior.
Meteorite (iron)
Thought to represent the core of a planet-like object, which formed early in the history of the solar system.
Meteorite (stony)
Thought to represent the mantle of a planet-like object.
Moho
Boundary broadly between the crust and the mantle where P and S wave velocities decrease.
Ophiolite
sections of the oceanic crust that have been tectonically moved onto continental crust.
Partial melting
Occurs when a small proportion of the rock melts, usually between 1 and 5%.
peridotite
An ultramafic igneous rock composed of the minerals olivine and pyroxene.
rheid
A non-molten solid that deforms by viscous or plastic flow, in response to an applied force.
seismic
vibration generated by an earthquake, explosion, or similar energetic source.
seismogram
The paper or electronic record made by a seismograph.