1http://www.physicalgeography.net/fundamentals/images/lava_corelp0323283.JPG

Chapter4Chapter4IgneousRocksIgneousRocks

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks22www.matt-willard.com/Artwork/Graphic_Design/Rock-Cycle.jpg

Whatisarock?

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

Magmatismformation of igneous rocks from magma

Plutonismintrusive igneous rock crystallizes from magma and slowly

cools below the surface of the Earth

Volcanismincludes all phenomena resulting from and causing magma within the crust or mantle of a planet to rise

through the crust and form volcanic rocks on the surface

Igneousprocesses

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

WHAT IS MAGMA?molten rock located beneath the

surface of the Earth, and which often collects in a magma chamber.

a complex high-temperature (~650 -~1200 C) silicate solution that is ancestral to all igneous rocks

capable of intrusion into adjacent crustal rocks (plutonism)

capable of extrusion onto the surface (volcanism), sometimes emerges through volcanic vents as lavas and pyroclastic ejecta

collects in many separate magma chambers within the Earth's crust; different compositions in different places

earth.geol.ksu.edu/sgao/g100/plots/1003_magma_chamber.jpg

Magmatism

2N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

Formation of magmasFormation of magmasby by partial meltingpartial melting of rocks through heating and fluxing with waterof rocks through heating and fluxing with water

e.g., e.g., subductionsubduction zoneszones

by by decompressiondecompressione.g., mide.g., mid--oceanic ridges oceanic ridges

Magmatism

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

MAGMA TYPES/COMPOSITION

FELSIC(RHYOLITIC)

INTERMEDIATE(ANDESITIC)

MAFIC(BASALTIC)

ULTRAMAFIC(PICRITIC)

SiO2 > 70% ~ 60% < 50% < 45%Fe - Mg ~ 2% ~ 3% ~ 4% >8% - 32%

MgOTemperature 700C ~1000C up to

~1200Cup to

~1500CViscosity High Intermediate Low Low to Very

LowEruptive behavior

explosive explosive gentle gentle

Magmas

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

CRYSTALLIZATON AND THE BOWENS REACTION SERIES

http://www.georgiacenter.uga.edu/idl/webid/portfolio/graphics/illustrations/bowdens_reaction.jpg

Magmatism

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

earth.geol.ksu.edu/sgao/g100/plots/1003_magma_chamber.jpg

CLASSIFICATIONPLUTONIC VS. VOLCANIC VS. PYROCLASTIC

Igneousrocks

3N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

PLUTONIC ROCKS

http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/Earth_Structure/igenous%20landforms.jpg

Igneousrocks

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

CLASSIFICATION

volcanoes.usgs.gov/Imgs/Gif/Drawings/RockClassif-B.gif

Igneousrocks

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

COMPOSITION (Color Index)

TEXTURE FELSIC INTERMEDIATE MAFIC ULTRAMAFICphaneritic granite diorite gabbro peridotite

aphanitic/ porphyritic

rhyolite andesite basalt basalt

vesicular pumice pumice scoriaglassy obsidian

fragmental Agglomerate, volcanic breccia, lapilli stone, tuff

IDENTIFICATIONIgneousrocks

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

PLUTONIC AND VOLCANIC ROCKS

http://www.geo.umn.edu/mgs/virt_egg/granite.jpg

GRANITE(PHANERITIC)

http://csmres.jmu.edu/geollab/Fichter/IgnRx/HTMLimag/Diorite-3A1.11.JPG

DIORITE

http://www.geo.umn.edu/mgs/virt_egg/gabbro.jpg

GABBRO

http://www.pitt.edu/~cejones/GeoImages/1Minerals/1IgneousMineralz/Olivine/

Peridotite.jpg

PERIDOTITE

http://www.mii.org/Minerals/Minpics1/Rhyolite.jpg

RHYOLITE(APHANITIC)

http://volcanoes.usgs.gov/Imgs/Jpg/Lassen/And-Brokeoff_med.jpg

ANDESITE

http://volcano.und.edu/vwdocs/vwlessons/rocks_pics/basalt.jpg

BASALT

http://www.pitt.edu/~cejones/GeoImages/2IgneousRocks/IgneousCompositions/

1Ultramafic/OlivineThumb.jpg

KOMATIITE

http://www.drexel.edu/coe/enggeo/rocks1/rhyolite_porphyry800.jpg

PORPH. RHYOLITE(PORPHYRITIC)

http://perso.orange.fr/jacques.delfour/photos/andesit.jpg

PORPH. ANDESITE

http://www.ukge.co.uk/UKGEDATA/images_versions/5275.jpg

PORPH. BASALT

Igneousrocks

4N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

FRAGMENTAL/PYROCLASTIC ROCKS

GLASSY ROCK

http://resourcescommittee.house.gov/subcommittees/emr/usgsweb/photo

gallery/images/Pumice%203_jpg.jpg

PUMICE

http://www.nps.gov/tont/nature/graphics/InsideOutside/scoria.jpg

SCORIA

http://homepage.smc.edu/robinson_richard/rocktest/igneous_web/images/

tuff%20breccia%202.jpg

TUFF

http://www.decadevolcano.net/photos/keywords/photos/P5071453.jpg

IGNIMBRITE

http://www.texasbeyondhistory.net/kids/images/obsidian-sm.jpg

OBSIDIAN

Igneousrocks

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

Philippine Philippine metallic minesmetallic mines

Igneousrocksandmineralresources

66331133

272711

55

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

Philippine Philippine metallic minesmetallic mines

Igneousrocksandmineralresources

66331133

272711

55Ore Asia Mining & Development Ore Asia Mining & Development CorporationCorporation

Lepanto ConsolidatedLepanto ConsolidatedMining CompanyMining Company

PhilexPhilex Mining CorporationMining Corporation

KromincoKrominco Inc.Inc.

Rio Tuba Nickel Rio Tuba Nickel Mining CorporationMining Corporation

Rapu-RapuMinerals, Inc.

Oceana Gold (Philippines), Inc.Oceana Gold (Philippines), Inc.

N. Ramos | Geology 11 Principles of Geology Lecture Notes: Igneous Rocks

Review: Plate tectonics and the formation of metallic and non-metallic resources

Igneousrocksandmineralresources