Igneous Rocks and

Processes

Other minerals are important for the full description of igneous rocks:

Olivine, Pyroxene, Hornblende, Biotite and Muscovite

General Classification of Igneous Rocks

Extrusive Rocks(Volcanic)

Intrusive Rocks (Plutonic)

General Classification of Igneous Rocks

MaficFelsic Intermediate

Increasing Fe & Mg

Increasing Si & Al

Common Igneous Rocks

Fine

Grained

(Extrusive)

Coarse

Grained

(Intrusive)

Felsic Intermediate Mafic

Rhyolite Andesite Basalt

Granite Diorite Gabbro

Classification of Igneous Rocks

Streckheisen classification is based on only three minerals:

Quartz, Plagioclase, Potassium Feldspar

Norman Bowen (1887-1956)Father of Experimental Petrology

Bowen’s Reaction SeriesPredictable Mineral Associations

Bowen’s Reaction Series

Discontinuous Series

Bowen’s Reaction SeriesWhat is the trend in silicate structures? Why?

Discontinuous Series

Bowen’s Reaction Series

Continuous Series

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

Metamorphic Rocks

and Metamorphic Processes

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

Classification of Metamorphic Rocks

Foliated (Banded) Non-Foliated (Massive)

Classification of

Foliated Metamorphic Rocks

Slate Schist Gneiss

Increasing Temperature

Metamorphic Texture Changes

Granite Gneiss

Formation of

Foliated Metamorphic Rocks

Shale Gneiss

Mic

roscope

Hand S

am

ple

Schist

Classification of

Non-Foliated Metamorphic Rocks

Quartzite Marble Serpentinite

Sandstone Limestone Peridotite

Metamorphic Texture Changes

Quartz Arenite

Quartzite

Metamorphic Texture Changes

Quartz Arenite

Quartzite

Limestone Marble

Metamorphic Facies

The Rock Cycle

Identifying Rocks

Foliated/Layered Non-Foliated/Non-Layered

Sedimentary Metamorphic Igneous

Identifying Rocks

Grains Crystals

Sedimentary Metamorphic Igneous

Composition of the Crust

GraniteBasalt,

Gabbro

Si, Al,

Na, KSi, Al,

Ca, Fe, Mg

Composition of the Earth

Plate Tectonics

Pangea

Distribution of Late Paleozoic

Fossils

Bathymetry of the Ocean Floor

Volcanoes of the World

Volcanoes Correlate Globally with

Deep Earthquakes

Benioff Zone of Seismicity

Plate Tectonic Model

Mantle Convection

Tectonic Plates