69 terms

Plate Tectonics

Plate tectonics and the ocean floor flash cards.
Volcanic rock common in continental arcs.
A "plastic" or highly viscous top layer of mantle just below the lithosphere.
The last stage in reef formation when a landmass becomes completely submerged, but the coral reef continues to grow.
Barrier Reef
The second stage in reef formation. They can be linear or circular and are separated from the landmass by a well-developed lagoon.
An igneous (volcanic) rock that is very dense and makes up a good bit of the oceanic crust.
Continental Accretion
A process that adds material to continents.
Continental Arc
A volcanic arc that forms along the edge of a continent above a subduction zone.
Continental Crust
A layer of rock, mostly granite, that makes up the continents.
Continental Drift
An idea by Alfred Wegener that the continents were slowly drifting across the globe. It was a precursor to Plate Tectonics.
Continental Transform Fault
A transform fault (movement of one plate past another) that cuts across a continent.
Convection Cell
The mechanism thought to be behind sea floor spreading. It's a circular-moving loop of matter.
Convergent Boundary
A lithospheric plate boundary where two plates collide producing island arc systems, continental volcanic arcs, or folded mountain ranges.
Coral Reef
A marine ridge or reef consisting of coral and other organic material consolidated into limestone that goes through 3 stages of develoment.
The innermost part of the Earth with a solid interior of mostly iron and nickel and a liquid exterior of the same material.
Makes up the oceanic plates (of basalt) and continental plates (of granite).
Curie Point
The temperature at which magnetic signatures are "set" in basalt.
Charles Darwin
A naturalist who, among other things, hypothesized about coral development during his voyage on the HMS Beagle.
Divergent Boundary
A plate boundary where two plates are moving apart, such as along the crest of the mid-ocean ridge where sea floor spreading is occurring. Rift valleys are common.
East Pacific Rise
This is a gently sloping and fast-spreading part of the mid-ocean ridge between the Nazca and Pacific Plates with a small central rift valley.
Fringing Reef
This is the first stage in reef development. They initially develop along the margin of a landmass where conditions are just right and are often associated with volcanoes.
A hypothetical ancient protocontinent made up of Africa, Antarctica, Australia, India, and South America.
Great Barrier Reef
The largest reef system in the world near northeastern coast of Australia.
Another name for a tablemount; a flat-top peak on the ocean floor.
Hawaiian Islands-Emperor Seamount Chain
An island chain oriented in a NW direction in the Pacific Plate made up of over 100 volcanoes.
Heat Flow
The measurement of heat moving from Earth's interior to the surface.
Harry Hess
A geologist who published the idea of sea floor spreading with convection cells as the driving mechanism.
Hot Spot
A relatively stationary surface expression of a persistent column of molten mantle rising to the surface.
Ice Age
A glacial period in Earth's history.
Inner Core
Inner-most part of the Earth made of solid material, mostly iron and nickel.
Isostatic Adjustment
Adjustment of crustal material due to the reaching equilibrium in which the rigid crustal units float on the underlying mantle.
Isostatic Rebound
The upward movement of crustal material due to reaching equilibrium in which the rigid crustal units float on the underlying mantle.
A protocontinent of the Northern Hemisphere composed of North America and Eurasia.
The outer layer of Earth's structure that is broken into plates.
Magnetic Anomaly
Distortion of the regular pattern of Earth's magnetic field, resulting from the various magnetic properties of local concentrations of minerals in Earth's crust.
Magnetic Dip
The dip of magnetite particles in rock units of Earth's crust relative to sea level. It is approximately equivalent to the latitude at which the rock formed.
Magnetic Field
The region surrounding a magnet or celestial object that generates magnetism that is influenced by that magnetism.
Magnetic Inclination
Another term for magnetic dip.
A naturally magnetic iron mineral found in igneous rocks.
The zone between the core and the crust of the Earth.
Mantle Plume
Columns of molten material that arise from deep within the mantle and erupt onto Earth's surface at relatively fixed locations called hot spots.
Mid-Atlantic Ridge
A slow-spreading divergent plate boundary running north-south and bisecting the Atlantic Ocean.
Mid-Ocean Ridge
A linear volcanic mountain range that extends through all the ocean basins.
A linear chain of islands and/or seamounts that are progressively older in one direction. It is created by passage of a tectonic plate over a hotspot.
Ocean Trench
A long linear depression in the ocean floor associated with subduction on one oceanic tectonic plate beneath another oceanic plate or continental plate.
Oceanic Crust
A thick mass of igneous rock (basalt) which lies under the ocean floor.
Oceanic Ridge
Any section of the narrow, largely continuous range of submarine mountains that extends into all the major oceans and at which new oceanic lithosphere is created by the rise of magma from the earth's interior.
Oceanic Rise
A long, broad elevation of the bottom of the ocean.
Oceanic Transform Fault
Faults on the ocean floor that neither create nor destroy lithosphere, whose relative motion is horizontal . They form a series of short zigzags accommodating seafloor spreading.
Outer Core
The outer most section of Earth's interior that is composed of thick liquid iron and nickel.
The study of Earth's ancient magnetic field.
An ancient supercontinent of the geologic past that contained all the continents.
Plate Tectonics
The theory that the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.
Polar Wandering Curve
A curve that shows apparent change in the location of Earth's poles over time.
Intrinsic polar separation, alignment, or orientation, especially of a physical property like magnetic or electrical ones.
Rift Valley
A deep fracture or break, extending along the crest of a mid-ocean ridge.
The movement of two plates in opposite directions such as along a divergent boundary.
San Andreas Fault
A transform fault that cuts across California from the northern end of the Gulf of California to Point Arena north of San Francisco.
Sea Floor Spreading
A process producing the lithosphere when convective upwelling of magma along the oceanic ridges moves the ocean floor away from the ridge axes.
An individual peak extending more than 1000 meters above the ocean floor.
Spreading Center
A divergent plate boundary.
A process by which one lithospheric plate descends beneath another. The surface expression of such a process may be an island arc-trench system or a folded mountain range.
Subduction Zone
A long narrow region beneath Earth's surface in which subduction takes place.
A flat-topped seamount; a guyot.
Transform Boundary
The boundary between two lithospheric plates formed by a transform fault.
Transform Fault
A fault characteristic of oceanic ridges along which they are offset.
The property of a substance to offer resistance to flow; internal friction.
Volcanic Arc
An arc-shaped row of active volcanoes directly above a subduction zone. Can occur as a row of islands (island arc) or mountains on land (continental arc).
Alfred Wegener
A German meteorologist and geophysicist who was the first to advance the idea of mobile continents in 1912 (Continental Drift).
Wilson Cycle
A cycle that illustrates the process by which ocean basins form as a result of continental rifting, growth, and then destruction by plate tectonic processes.