Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Exam 1 Earth Science
Igneous Rocks
| Term | Definition |
|---|---|
| Igneous | soldification of magma or molten, most abundant is BASALT, most abundant IN earths crust |
| Sedimentary | breakdown of preexisting rocks followed by transport and depostion |
| Metamorphic | recrystalization of igneous and sedimentary rocks with earth |
| Phase diagrams | solid, liquid, gas. Dependent on temp, pressurem and composition. Pressure y-axis, temp x-axis |
| temperatures | earth mostly solid, magma forms when temp high, Basalt erupts at 1200 C, melting occurs in mantle below lithosphere |
| geotherm | gives variation of temp with deep in Earth. Temp along this is too low to cause melting in mantle |
| solidus | gives temp necessary for melting to occur |
| anhydrous | without water |
| decompression melting | mantle rises from point a then you bring up to point b where the pressure is lower so it can melt and rise to surface. Occurs at DIVERGENT margins and within mantle plumes |
| divergent margins | occurs as response to lithosphere stretching and thinning. Plates pull apart, mantle rises to replace missing lithosphere, mantle melts to create magma. Passive bc mantle reacts to litho not cause of own |
| Flex melting and subduction | water added to mantle at subduction zones can cause melting to solid mantle because chemical composition changes, and lowers solidus temps causing it to melt without increasing its temperature |
| crystalline structures | interlocking grains, no spaces between grains, common in igneous |
| clastic texture | spaces between grains. May be filled later by cement, common in sedimentary |
| cooling and solidification | involves formation and growth of crystals, submicroscopic nuclei form, atoms must diffuse through melt and become attached to solids for bigger crystals |
| diffusion | takes longer to grow large crystals than small ones |
| rapid cooling forms | forms fine grained lava (rhyorite), and glass (obsedion), extrusive |
| slow cooling forms | forms coarse grained plutoic rocks, gabbro or granite, intrusive |
| extrusion | eruption of basaltic lava flow, can be gentle like lava or explosive, on the SURFACE |
| types of extruded rocks | Basalt (lava, fine grain), Pumice (explosive eruption, vesicular), obsedion (volcanic glass) |
| intrusive | magma chambers in volcanoes. In chambers, surrounding rocks act as blanket causing the heat to take longer exiting the magma so magma solidifies slowly to form coarse grained rocks. CREATES CRUST |
| How intrustive rocks are characterized | by contacts with the host rocks |
| Batholith | large body with irregular contacts |
| Sill | intrusive sheet approximately parallel to earths surface (horizontal) |
| Dike | intrusive sheet approximaley perpendicular to earths surface (vertical) |
| Volcanic neck | eroded remnant of volcano |
| Phaneritic | all coarse grained igneous rocks, granite and gabbro |
| Chemical comp of magma | 8 elements make up more than 98% of earths crust, 12 make up 99.23%. Oxygen most abundant and easy to report elements as oxides |
| Mafic | Basaltic magma rich in MgO, FeO, CaO, poor in SiO2, alkalis, dark colored, gabbro, basalt |
| Felsic | Rhyolite magma relatively rich in SiO2, alkalis and poor in MgO, FeO, CaO, light colored, rhyorite, granite |
| Intermediate Comp | andestic magma, mix of mafic and felsic, diorite, andersite |
| Foresterite | Mg heavy, melts at higher temp |
| Fayalite | Fe heavy, melts at lower temp |
| Partial melting of silicates | when you have minerals combine and ones that take lower temps will melt first leaving behind the other element as solid |
| parital crystallization | Whatever mineral in the compostion crystallizes at a lower temp |
| zoned | layers in a rock of different compositions |
| liquid composition | rich in silicon and alkalis, poor in magnesium, iron, and calcium |
| crystalizaiton differentiation | as you crystalize, you remove mafic elements (Fe and Mg), then it becomes more felsic. Basalt turning into Rhyolite/Granite |
| equilibrium composition | compositiion doesn't change. Start mafic, end mafic |
| Fractional crystalization | As magma cools, different minerals form at different temperature. Minerals denser than surrounding liquid sink to bottom of the magma chamber. This alters the remaining magmas composition leaving it rich in silica which remained in a liquid phase |
| Bowens reaction series | order in which minerals will crystallize given enough magma upon cooling. Mafic to felsic |
| assimilation | take mafic magma and turn it into crust and it has some parital melting but it mixes back into the orignial magma. Intermediate composition |
| magma mixing | 2 different composition of magma run into each other to create intermediate composition |
| Glassy | cooled super quick (obsedion) |
| vesicular | has gas bubbles (pumice or scoria) |
| pyroclastic | broken bits of volcanic rocks (tuff) |
| porphyritic | mix of coarse and fine grained minerals |
| Oceanic | Mafic, new crust forms at divergent margins as asthenosphere rises as plates move apart |
| Continential | melting in plume produces thick basaltic crust, granite magma (Felsic) |
| proto continent | igenous rocks at convergent margins added to edges of continents causing them to grow over time. Most added material is intrsuive. Contient cannot be subducted |
| shields | oldest rocks on earth (archean). Include silic (granitic) masses |
Created by:
omckenna52