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ROCKS
Granitic rock
Duero River
• Earth and Planets are built on rocks
• Rocks are formed on minerals.
minerals Actually every
one is a system in which the chemical
components are organized
i d in
i different
diff
phases‐
h
the minerals ‐ as the answer to the
physicochemical conditions‐ the factors ‐ that
were present at their generation.
• The phases are distributed following a
particular
ti l geometric
t i arrangementt ‐ structure,
t t
microstructure – that is also the consequence
of physicochemical conditions .
• To be used in building they must be able
of being cut in blocks and slices,
slices
polished, carved, etc.
• Depending
p
g on their composition
p
and
structure they show different mechanical
properties like charge resistance,
resistance
hardness, etc.
• And different behavior when they are
cut,
t abraded
b d d and
d suffer
ff weathering,
th i
or
anyy kind of chemical alteration.
• Therefore,, theyy are three bigg ggroups
p of rocks
depending on their minerals and structure,
that are consequence of their origin
•IGNEOUS
•SEDIMENTARY
•METAMORPHIC
METAMORPHIC
Rocks cycle
http:www.minsocam.org
Rocks classification
Rocks classification
• There are different criterion for classification:
• The more general is based in the quantity of The more general is based in the quantity of
the forming minerals that are organized as
• Primary:
Pi
– Essential: more than 5% in volume
– Accessory: less than 5% in volume
• Secondary: formed after any primary
• This general system is mainly working for igneous g
y
y
g
g
rocks
IGNEOUS
• They are formed by solidification of a melt,
mainlyy silicate made, rarelyy carbonate, formed
in the interior of the Earth, in the Mantle or
the Crust :
‐VOLCANIC‐ they solidify on the terrestrial surface
y
y
‐PLUTONIC‐ they solidify in the interior
IGNEOUS ‐
‐VOLCANIC‐ they use to be porous, having isotropic
structure, or less penetrative orientation:
‐massive‐ basalt, andesite, rhyolite, trachyte, etc.
fragmentary they can consolidate forming tuffs
‐fragmentary‐
‐PLUTONIC‐
PLUTONIC massive,
i
non porous, they
th
use to
t be
b
isotropic although they can also be oriented :
gabbro, diorite, granite, syenite, monzonite,
anorthosite, etc.
Classification of Igneous Rocks
volcanic
I.U.G.S.-UNESCO
plutonic
Massif volcanic rocks
Lava flows
Basalt
Fragmentary volcanic rocks
Tuffs
(ignimbrites)
Massif
ass volcanic
o ca c rocks
oc s
Trachyte
Plutonic
Granite
Guisando’s Bulls-Ávila
Plutonic
Vilvestre
Granite
Bernardos phyllite
Mº de El Escorial
Magmatic foliation
phenocryst
porphyritic
porphyritic
Granites: different types
In general, the color is darker in the sense of the arrow
Plutonic
G bb Di it
Gabbro-Diorite
SEDIMENTARY
• They are originated on the earth surface, and
consolidate at moderate deepness by burial,
reaching up about 200 ºC
• They use to be porous, there are two big groups:
‐Terrigenous clastic rocks
‐Chemical and organic origin
SEDIMENTARY
• TTerrigenous
i
clastic–
l i They
Th are formed
f
d through
h
h the
h
breaking of any previous rock. The fragments, clasts,
accumulate
l
and
d have
h
i
interstitial
i i l material
i l like
lik matrix
i
and cement. They are buried and compacted during
a process called
ll d diagenesis
di
i .
• The classification is made following the size of clasts :
‐ conglomerates,
sandstones,
limolites
‐
2mm
0,0625mm
• CHEMICAL and ORGANIC ORIGIN – due to chemical
precipitation and biological activity:
‐ limestones, dolostones, gypsum, silexites, etc
Conglomerate
clast
cement
Casa de las Conchas
Salamanca
Sandstone
conglomerate
granite
it
Sergilla-Syria, first century A.D.
limestone
Limestone blocks
Silex nodules
Al Russafah-Syria
outcrop
Gypsum
METAMORPHIC • They result from the
transformation
f
i
off any
previous rock (protolith),
that
h must be
b adapted
d
d to
new
physicochemical
conditions
di i
‐Pressure
P
and
d
Temperature –that are
ti
l
ti
operating
along
a time
(PTt)
Met. Facies
t
P
Regional Trayectory
Contact Trayectory
T
METAMORPHIC
• Non porous
• They are classified after their structure:
Th
l ifi d ft th i t t
– Isotropic‐ “felses”, granofelses: marble (carbonate fels), quartzite, hornfels, granulite, eclogite, etc.
– Oriented‐ slate, phyllite, schist, gneiss, migmatite, ,p y
,
,g
, g
,
Several other names are based in mineral composition having any structure: having any structure
:
amphibolite, serpentinite, etc
– Usually
Usually the structural name is combined with the names of the minerals that the structural name is combined with the names of the minerals that
form the rock, except several particular terms used by tradition – When the protolith is identified , the name can be the one of the protolith with the prefix “meta”
the prefix meta
microstructures
Isotropic -marble
Oriented-schist
Quartzite
chozo
In situ
Slate-phyillite
Schist
G i
Gneiss
Migmatite
Foliated
Amphibolite
schist
Marble
Macael-Spain
carbonate
veins
Serpentinite
Tessellated pavement-Carranque
(Toledo)
IV Century A.D.
Natural rolling stones
Philip of Macedonia Palace in PellaGreece
̴ 300 y. B C
basalt
limestone
outcrop
Crak des Chevaliers -Syria
granite columns
Baalbek-Lebanon
limestone
Palace in Damask-Rocks having different colors
END