|
Aquifer
- a porous or fractured body of rock carrying cold or hot water.
Basin or Sedimentary
basin - a bowl-shaped
depression in the earth filled with sedimentary rocks (rocks
usually formed in water such as sandstone, limestone, etc.).
Fault
- a break in the earth's crust which extends a considerable
distance (horizontally and vertically) along which relative
(sliding) movement occurs.
Fumarole
- a flow of steam from the ground. Fumaroles can be weak or
strong, noisy and superheated (temperature above boiling).
Hot spot
- a relatively small area of a plate heated by a rising plume
of magma from deep within the mantle which produces local volcanic
activity over a long time period.
Plate -
a rigid part of the earth's crust that moves relative to other
plates. The map shows eight major plates and several minor ones.
|
Plate boundary
- where two plates meet. When plates move apart they form a
rift boundary (e.g. the North American and Eurasian plates).
When they move together they can bump to form a collision boundary
(e.g. the Indian and Eurasian plates) or one can slide under
the other to form a subduction boundary (e.g. the Nazca and
South American plates). Sometimes plates just slide past each
other along a fault boundary (e.g. the San Andreas fault between
the North American and Pacific Plates). Some boundaries (e.g.
through Siberia) are poorly defined.
Rift
- a part of the crust that has been pulled apart, usually bordered
by faults. A rift zone is a rift with bordering faults. When
rifting occurs, magma can move near the surface, forming volcanoes
and geothermal systems. Rift zones may become plate boundaries.
Sinter
- a white or gray surface deposit from a hot spring or geyser
consisting of silica (SiO2). Travertine is a similar deposit
consisting of carbonate (usually CaCO3).
|
