The Rock Cyclex

kayakjokeMécanique

22 févr. 2014 (il y a 3 années et 1 mois)

83 vue(s)


The
rock cycle

is a fundamental concept in
geology

that describes the dynamic
transitions through
geologic time

among the
three main
rock

types:
sedimentary
,
metamorphic
, and
igneous
.


Rocks are formed from cooled magma the
slower they cool the larger the crystals are.
They can be cooled underground and are
called intrusive; if they are cooled above
ground they are extrusive.


A rock resulting from the
change of preexisting rock as
a result of the effect of heat ,
pressure, chemical action or
combination of these.

A rock formed from precipitation from a solution , by
accumulation of organic materials or by sedimentation and
cementation of sediments derived from preexisting rocks and
transported to a site of deposition by water , wind or ice.


Types of Sedimentary rocks
:

Clastic

: fragmented rock

Crystalline,


sedimentary rock that has interlocking crystals.

Amorphou
s: very compact texture finely divided non crystalline
material.


oolitic
: spheroid particles less than 2 millimeters called ooliths.


bioclastic
: This texture Is produced by aggregation of fragments
of organic remains , the most common of which are shell
fragments. .


When liquid or hot magma/lava is reduced in
temperature until it becomes solid.


Heating: When a rock is heated and the
temperature increases until it changes shape
or becomes liquid magma.


Pressure:
Pressure

(the symbol:
P
) is the
force

per unit
area

applied in a direction
perpendicular

to the surface of an object.
Gauge pressure

is the pressure relative to the
local atmospheric or ambient pressure.



The combination of processes that convert a
sediment into sedimentary rock


Intrusive : magma that slowly cools
underground forming crystals.



Extrusive: lava that cools rather quickly above
the ground.