Page 1
Igneous Rocks and
Processes
Page 2
Other minerals are important for the full description of igneous rocks:
Olivine, Pyroxene, Hornblende, Biotite and Muscovite
Page 3
General Classification of Igneous Rocks
Extrusive Rocks(Volcanic)
Intrusive Rocks (Plutonic)
Page 4
General Classification of Igneous Rocks
MaficFelsic Intermediate
Increasing Fe & Mg
Increasing Si & Al
Page 5
Common Igneous Rocks
Fine
Grained
(Extrusive)
Coarse
Grained
(Intrusive)
Felsic Intermediate Mafic
Rhyolite Andesite Basalt
Granite Diorite Gabbro
Page 6
Classification of Igneous Rocks
Streckheisen classification is based on only three minerals:
Quartz, Plagioclase, Potassium Feldspar
Page 7
Norman Bowen (1887-1956)Father of Experimental Petrology
Page 8
Bowen’s Reaction SeriesPredictable Mineral Associations
Page 9
Bowen’s Reaction Series
Discontinuous Series
Page 10
Bowen’s Reaction SeriesWhat is the trend in silicate structures? Why?
Discontinuous Series
Page 11
Bowen’s Reaction Series
Continuous Series
Page 12
Bowen’s Reaction SeriesWhy would aspects of this igneous concept apply to
sedimentary rocks as well?
Least Common Minerals in Sediments
Most Common Minerals in Sediments
Page 13
Metamorphic Rocks
and Metamorphic Processes
Page 14
General Rules of Metamorphism
Metamorphism is due to solid-state reactions between minerals due to change in temperature and pressure
Most metamorphic reactions liberate volatiles(H2O and CO2)
The minerals in low-grade metamorphic rocks have more volatiles than high-grade metamorphic rocks e.g., micas amphiboles pyroxenes
Increasing metamorphic grade generally corresponds to increasing grain size e.g., clays micas
Page 15
Classification of Metamorphic Rocks
Foliated (Banded) Non-Foliated (Massive)
Page 16
Classification of
Foliated Metamorphic Rocks
Slate Schist Gneiss
Increasing Temperature
Page 17
Metamorphic Texture Changes
Granite Gneiss
Page 18
Formation of
Foliated Metamorphic Rocks
Shale Gneiss
Mic
roscope
Hand S
am
ple
Schist
Page 19
Classification of
Non-Foliated Metamorphic Rocks
Quartzite Marble Serpentinite
Sandstone Limestone Peridotite
Page 20
Metamorphic Texture Changes
Quartz Arenite
Quartzite
Page 21
Metamorphic Texture Changes
Quartz Arenite
Quartzite
Limestone Marble
Page 22
Metamorphic Facies
Page 24
Identifying Rocks
Foliated/Layered Non-Foliated/Non-Layered
Sedimentary Metamorphic Igneous
Page 25
Identifying Rocks
Grains Crystals
Sedimentary Metamorphic Igneous
Page 27
Composition of the Crust
GraniteBasalt,
Gabbro
Si, Al,
Na, KSi, Al,
Ca, Fe, Mg
Page 28
Composition of the Earth
Page 31
Distribution of Late Paleozoic
Fossils
Page 32
Bathymetry of the Ocean Floor
Page 34
Volcanoes of the World
Page 35
Volcanoes Correlate Globally with
Deep Earthquakes
Page 36
Benioff Zone of Seismicity
Page 37
Plate Tectonic Model
Page 38
Mantle Convection