Flashcards
Continental Drift Definitions
Cards in this deck (21)
- 1Define continentssituated on crust with an average thickness of 33km and a mean composition close to that of granite
- 2Define seismic tomographyis a computer imaging technique based on seismic wave velocities
- 3Define diapirlow density, buoyant material rising upwards in the same way as hot wax does in a lava lamp
- 4Define mantle plumea stationary area of high heat flow in the mantle, which rises from great depths and produces magma that feeds hot spot volcanoes
- 5Define hot spota volcano within a plate, which is the surface expression of a mantle plume
- 6Define oceanic platehas no continental material
- 7Define continental platecarries a continent but will also have oceanic crust
- 8Define lithospheredivided into plates, carried by the moving underlying asthenosphere.
- 9Define lithosphere platea layer of thecrust and upper mantle in which the rocks are rigid and brittle
- 10Define depth of focusearthquakes are classified by their depth at which the stress acts
(see 1.3.5) - 11Define ocean basinsare situated on crust with an average thickness of only 7km, formed maninly of rocks with a basaltic composition
- 12Define continental driftthe large sclae horizontal movement of continents during geological time
- 13Define clasticssediments made up of fragments of pre-existing rock
- 14Define planktonicorganisms that float in sea water
- 15Define pelagicis applied to organisms living in, and sediment deposited from, the main body of sea water
- 16Define maficigneous rocks with 45-52% silica, such as basalt
- 17Define gravimetercan be towed behind a ship to measure changes in gravity. (see notes - 1.3.2)
- 18Define magnetometeris towed behind a ship to measure changes is magnetism. It can detect the strength and direction of the magentic field
- 19Define apparent polar wandering curveis depicted by a line on a map, which joins up the apparent positions of the magentic north pole over time
- 20Define evaporitesminerals fomed by the evaporation of saline water for example: calcite, halite, gypsum, k-salts
- 21Define tillitesancient glacial deposits preserved within a rock sequence
Information
- Description
- Undergraduate Geology - Part 1 (Continental Drift) Flashcards on Continental Drift Definitions, created by siobhan.quirk on 08/05/2013.
- Created by
- siobhan.quirk
- Views
- 280
- Tags
- Rating