Dictionary of Meaning
<<Back
Please select a letter:
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
0-9
Click here for Shopping
Rock (geology)
*** Shopping-Tip: Rock (geology)
Image:North america rock types.jpg thumb|100px|right|[[:Image:North america rock sedimentary.jpg|Sedimentary,
:Image:North america rock volcanic.jpg volcanic,
:Image:North america rock plutonic.jpg plutonic,
:Image:North america rock metamorphic.jpg metamorphic rock types of
North America. ]]
'''Rock''' is a naturally occurring aggregate of
minerals and/or
mineraloids. Rocks are classified by
mineral and
chemical composition; the texture of the constituent particles; and also by the processes that formed them. These indicators separate rocks into
igneous rock igneous,
sedimentary rock sedimentary, and
metamorphic rock metamorphic.
'''
Igneous rocks''' are formed from molten
magma and are divided into two main categories: Plutonic rock and Volcanic rock.
''
Intrusion Plutonic rocks'' result when the magma cools and crystallises slowly within the Earth's crust, while ''
Volcanic rocks'' result from the magma reaching the surface either as
lava or fragmental ejecta.
'''
Sedimentary rocks''' are formed by deposition of either detrital or organic matter, or chemical precipitates (
evaporites), followed by compaction of the particulate matter and cementation. The latter can occur at or near the earth's surface, especially in the case of carbonate-rich sediments.
'''
Metamorphic rocks''' are formed by subjecting any rock type (including previously-formed metamorphic rock) to different
temperature and
pressure conditions than those in which the original rock was formed. These temperatures and pressures are always higher than those at the earth's surface, and must be sufficiently high so as to change the original minerals into other mineral types or else into other forms of the same minerals (e.g. by
recrystallisation).
The transformation of one rock type to another is described by the geological model called the
rock cycle.
The
Earth's crust (including the
lithosphere) and
Earth's mantle mantle are formed of rock.
Petrology is the study of rocks.
See also
*
List of minerals
*
List of rocks (geological)
*
List of stone (building stone)
*
Quarrying
*
Rock formations (a list of scenic features)
*
Megalith (Archaeology)
*
Riprap (civil engineering use)
Category:Petrology
Category:Materials
bg:Скала
ca:Roca
cs:Hornina
cy:Cerrig
da:Klippe (geologi)
de:Gestein
es:roca
et:Kivim
fr:Roche
fi:Kivi
he:סלע
hu:KÅ‘zet
id:Batu
it:roccia
ja:岩石
mk:Карпа
ms:Batu
nl:Rots
pl:Skała
pt:Rocha (geologia)
ro:piatră
ru:ГорнаÑ? порода
sl:Kamnina
sr:Стене
sv:bergart
th:หิน
tr:kayaç
vi:Ä?á (địa chất)
zh:岩石
*** Shopping-Tip: Rock (geology)
