Even more igenous rocks

Types of Igneous
Plutons

Volcano

Dikes
Laccolith
Sills

p.140-141d

Volcanic Pipe

Original artwork by Gary Hincks

Dikes
Batholith


Fig. 6.08b
Stephen Marshak



Types of Igneous
Plutons

Volcano

Dikes
Laccolith

Sills

p.140-141d

Volcanic Pipe

Original artwork by Gary Hincks

Dikes
Batholith


Fig. 6.10
W. W. Norton


Fig. 6.11a
Stephen Marshak


Fig. 6.11de
Paul Hoffmann


Fig. 6.18
W. W. Norton


Plate Tectonic Setting as a Context
For Magma Generation

1) Mantle
plumes &
hot-spots

3) Divergent
4) Melting of
2) Convergent
margins:Melting lithosphere &
margins:
of lithosphere
crust beneath
Subduction of
along ocean
continental rift
slabs of
spreading
zones
lithosphere
centers


Fig. 6.14ab
W. W. Norton


Ways To Melt Rock:

Fig.
Lower pressure

6.04a

in the mantle
(e.g. along W. W. Norton
divergent margins)


Fig. 6.03
W. W. Norton
“Decompression
melting”

Rock
moving
from point
A to point
B in the
mantle
sees a
decrease in
pressure.


Ways To Melt Rock

Fig. 6.04a

Raise the temperature

of the surrounding rock

W. W.
to melting temperature

Norton


Ways To Melt Rocks

Fig. 6.04c
Add
water!

W. W. Norton


Fig. 6.04b
W. W. Norton


Making Silica-rich Magmas

Fig. 6.05a
W. W. Norton

1) Partial melting of mafic, or ultramafic rocks.


Making Silica-rich

Magmas:

2) Assimilation of
siliceous “country
rocks”


Fig. 6.09ab
W. W. Norton


Making Silica-rich Magmas

Fig. 6.05c
W. W. Norton

3) Fractional crystallization & gravity settling
of early formedmafic minerals.