DOC PREVIEW
UM GEO 101N - Igneous Rocks
Type Lecture Note
Pages 5

This preview shows page 1-2 out of 5 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

GEO 101N 1st Edition Lecture 14Outline of Last Lecture I. Magma Formationa. Decompressionb. Volatile additionc. Heat TransferII. Major Types of MagmaIII. Magma Categoriesa. Felsicb. Intermediatec. Maficd. UltramaficIV. Magma MovementV. Rock MeltingVI. Magma CharacteristicsOutline of Current Lecture VII. Igneous Rocks (iclicker question included)VIII. Igneous TexturesIX. Extrusive v IntrusiveX. Classifying Igneous RocksXI. Cooling Time of MagmaXII. Fractional Chemical ReactionXIII. Bowens Reaction SeriesXIV. Volcano EruptionsXV. Volcano TypesCurrent LectureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.VII. Igneous Rocks *in what tectonic setting are water and carbon dioxide most likely to be found in large amounts?-volcanic arc above a subduction zone (due to subduction forcing water down into the earth where it is heated (to a gas) along with rock)a. Crystalline-interlocking crystals fit like puzzle piecesb. Fragmental- pieces of pre-existing rocks, often shatteredc. Glassy: solid glass or glass shards-texture directly reflects magma historyVIII. Igneous Texturesa. Interlocking miniscule grains from solidifying melt b. Reveals cooling historyc. Porphyritic-coarse and fine crystals; cause by 2 stage coolingd. Dark or lighte. Grey, pink, white or blackf. When describing describe the overall hueIX. Intrusive v Extrusive a. Extrusive- cools at or near the surface-solidifies/cools fast-crystals are small or not existent b. Intrusive-magma cools at depth (“underground”) -loses heat slowly = crystal formation-Types1. Dike-a tabular intrusion that cuts across pre-existing layering2. Sill-a tabular intrusion that injects parallel to layering3. Laccolith-inject between layers then domes up, like a blisterc. Intrusive and extrusive rocks commonly form in associationd. Magma chambers feed volcanose. Magma chambers become plutons: blob shaped intrusions that range in size from 10’s of meters across to 10’s of km across f. A string of plutons across a region becomes a batholith (ie, the Sierra Nevada Mtn Range)Little Yosemite Valley, Sierra Nevada Mtns.X. Classifying Igneous Rocks1. Crystalline 2. Glassy (ie Obsidian, Pumice)3. Vesicles: gas bubbles caught in frozen lava, bubbles remain as open holesXI. Magma Coolinga. Depth of intrusion: magma intruded deep in the crust cools more slowlyb. Shape & size of magma body: heat escapes from magma @ the surface of the intrusion, greater surface are = less cool time requiredc. Groundwater: the presence of circulating groundwater leeches off the heat by absorbing it and carrying it awayXII. Fractional Crystallizationa. During the freezing of molten rock many different compounds (so many different minerals) form at the same timeb. “sequential” crystal formation & settling = fractional crystallization: progressively extracts Fe & Mg from remaining lava = FelsicXIII. Bowen’s Reaction SeriesXIV. Volcanic Eruptions-unpredictable, dangerous-eruptions can provide soil and minerals to the soil = fertilization-this helps feed the world-can extinguish populations-can affect the climate for limited time periodsXV. 4 Main Volcano Types1. Composite orStrato- volcano: likeyou drew as a kid2. Shield: looks likeinverted shield3. Scoria: small, showup around othervolcanoes4. Domes: domeshapedXVI. Surface Magma (Lava)1. Mafic: 1100ᵒ-extrudes; flowswell (low viscocity)- low gas content = lava flows-gabbro2. Felsic:600ᵒ; doesn’t flow well, explosive -seen w/Tuf ; a fine grained pyroclastic igneous rock made of volcanic ash; may contain fragments of pumice3. Intermediate: fairly explosive-diorite


View Full Document

UM GEO 101N - Igneous Rocks

Type: Lecture Note
Pages: 5
Download Igneous Rocks
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Igneous Rocks and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Igneous Rocks 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?