the full version of the plate tectonics vocabulary
East Africa Rift Zone
an active continental rift zone in eastern Africa that appears to be a developing a divergent tectonic plate boundary. It is part of the larger Great Rift Valley. The rift is a narrow zone in which the African Plate is in the process of splitting into two new tectonic plates and is home to some active as well as dormant volcanoes.
a ship that collected fossil samples from areas around the Mid-Atlantic Ridge, with the newest fossils closest to the ridge, giving evidence of seafloor spreading.
J Tuzo Wilson
suggested that Hawaii and other volcanic island chains may have formed due to the movement of a plate over a stationary hotspot in the mantle.
a group of rocks that has attached itself to a tectonic plate and migrated away from its place of origin.
single Landmass thought to have been the origin of all continents
Young Ocean Floor
new rock on the ocean floor caused by seafloor spreading; the movement of ocean floor away form either side of a mid-ocean ridge
border formed by the collision of two lithospheric plates
looping pattern of flowing magma
sourthern landmass that broke away from pangaea and later formed South America, Africa, India, Australia, and Antarctica
Layers of the Earth
the lithosphere: made up of the crust and a portion of the mantle, is divided into moving plates that ride on the denser asthenosphere: the layer made of plastic rock just under the lithosphere
boundary formed by two lithospheric plates that are moving apart
neither plate is subducted, because they have the same density, so the colliding edges are crumpled and uplifted, producing large mountain ridges including the Himalayas
the theory that all geologic phenomena may be explained as the result of existing forces having operated uniformly from the origin of the earth to the present time
region where one lithospheric plate moves under another
formed by the Eurasian and Indo-Australian plates colliding.
chain of volcanic islands formed along an ocean trench
hypothesis stating that the continents once formed a single landmass, broke up, and drifted into their present locations
hess and dietz
hess suggested the hypothesis, later named seafloor spreading by Dietz, in which the valley at the center of a ridge is actually a rift in the earth's crust where magma wells up, creating new rocks.
Ring of fire
an area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur, and is a direct result of plate tectonics and the movement and collision of crustal plates
boundary formed where 2 lithospheric plates slide past each other (San Andreas)
a german scientist who proposed a hypothesis known as continental drift, which stated that the continents had moved
system of undersea mountain ridges that wind around the earth
a chain of islands created by the pacific plate moving over a stationary hotspot wehre the magma rises above the mantle and crust to erupt on the seafloor
a collision where the less dense oceanic crust is subducted under the denser continental crust
wegener found identical fossil remains of Mesosaurus, an extinct reptile, on both eastern South America and western Africa, and since they couldn't have swam all that way and there weren't any known land bridges, they must have been connected at some point.
deep valleys in the ocean floor
areas of volcanism within a lithospheric plate
a useful way of telling geologic time... radiometric dating is a method of obtaining a rock's age by measuring the relative abundance of radioactive and radiogenic isotopes
mirrored patterns of reverse polarity and normal polarity on the ocean floor, with the line of symmetry being an ocean rift
225-200 million years ago
the supercontinent, Pangaea, began to break up, eventually forming the continents we know today
San Andreas Fault
a major transform boundary between the Pacific Plate and the North American plate
new madrid earthquake
an intraplate earthquake that can be estimated to have an 8.0 or greater magnitude on the not yet invented Richter scale
stripes of reveresed polarity and normal polarity that can be found on the oceans floor symmetrically on the sides of a rift.
an area of the earth's crust wehre movements, sometimes volcanism, occur. it is also known as a seismic area
lava and pyroclasitc material built up on the earth's surface around a vent
2.5 to 15 centimeters per year
the pace at which the earth's tectonics plates move
global positioning system...
using these you can figure out where a certain thing is and then measure the distance it moves
northern landmass that broke away from pangaea and later formed north america and eurasia
evidence of plate movement...
a deep ocean trench forms when these plates are subducted