Geol Set 3

Front 1

% Igneous in Crust =

Back 1

65%

Front 2

% Metamorphic in Crust =

Back 2

35%

Front 3

% Sedimentary in Crust =

Back 3

5%; 75% of Earth's Surface

Front 4

Pressure =

Back 4

Weight per Area

Front 5

Mixtures of minerals create disorder, so the melting point...

Back 5

lowers/decreases

Front 6

Lithostatic pressure creases order amongst the atoms in minerals, so the melting point...

Back 6

rises/increases

Front 7

Igneous rocks

Back 7

are HARD rocks that crystallize from a melt.

Front 8

Intrusive rock

Back 8

Forms from magma within Earth's surface

Front 9

Extrusive rock

Back 9

Forms from lava on Earth's surface

Front 10

Water pressure (hydrostatic pressure) decreases order, so melting points...

Back 10

lower/decrease

Front 11

Igneous activity is associated with...

Back 11

plate boundaries

Front 12

Igneous rocks are classified based upon:

Back 12

The temperature at which they form and their mode of origin (extrusive vs intrusive).

Front 13

The mode of origin reveals itself in ____________

Back 13

textures - the shape, size and appearance of mineral grains.

Front 14

Phaneritic

Back 14

Rocks formed intrusively that cool slowly and form with larger, visible mineral grains.

Front 15

Aphanatic

Back 15

Rocks formed extrusively that cool quickly and are characterized by fine-grained textures in which individual crystals are microscopic.

Front 16

Glassy

Back 16

Rock that cools so quickly that crystal structures do not form or do not form very well. leaving the rock as glass. These are rocks blown out of a volcanic erruption.
Ex. Obsidian

Front 17

Vesicular

Back 17

Porous; shows holes where gases escaped from rock as it cooled.

Front 18

Frothy

Back 18

Full of holes, making rock less dense than water. Rock is mostly air.
Ex. Pumice

Front 19

Pegmatitic

Back 19

Intrusive igneous rock with extremely large visible crystals. Form very slowly below the Earth's surface and often contain valuable minerals.

Front 20

Porphyritic

Back 20

Rocks that contain both large and small grains.

Front 21

At what temperature do most minerals melt?

Back 21

1600ºC

Front 22

Mafic Rocks

Back 22

The first rocks to form. Crystallize at high temperatures. Consist primarily of mafic minerals (olivine, horneblende, amphibole, calcium feldspar, and biotite mica). DARK in color.

Front 23

Silicic Rocks

Back 23

The last rocks to form; crystallize at low temperatures. Consist primarily of silicic and felsic minerals (quartz, muscovite mica, and kspar). Light in color.

Front 24

Intermediate rocks

Back 24

Crystalize at intermediate temperatures. Mixed in color (dark and light).

Front 25

Gabbro

Back 25

An intrusive (phaneritic) rock that forms at high temperatures (mafic).

Front 26

Diorite

Back 26

And intrusive (phaneritice) rock that forms at intermediate temps (intermediate).

Front 27

Granite

Back 27

An intrusive (phaneritic) rock that forms at low temps (silicic).

Front 28

Basalt

Back 28

An extrusive (aphanitic) rock that forms at high temps (mafic).

Front 29

Andesite

Back 29

An extrusive (aphanitic) rock that forms at intermediate temps (intermediate).

Front 30

Rhyolite

Back 30

And extrusive (aphanitic) rock that forms at low temps (silicic).

Front 31

Intrusive rock examples:

Back 31

Gabbro, Diorite & Granite

Front 32

Extrusive rock examples:

Back 32

Basalt, Andesite and Rhyolite

Front 33

Mafic rock examples:

Back 33

Gabbro and Basalt

Front 34

Intermediate rock examples:

Back 34

Andesite and Diorite

Front 35

Silicic rock examples:

Back 35

Granite and Rhyolite

Front 36

Partial Melting

Back 36

Lithospheric plate is dragged down to great depth, where temperature are only hot enough to melt silicic and felsic (quartz and feldspar) minerals. Only parts of the plate melt.

Front 37

Fractional Crystallization

Back 37

The segregation of magma chambers in terms of light and dark (silicic and mafic) minerals. This happens because mafic minerals will crystallize at the highest temps (first) and fall to the bottom of the chamber.

Front 38

Plutons

Back 38

Intrusive bodies of igneous rocks. 4 types:
- Batholiths - Stocks - Dikes - Sills

Front 39

Batholiths

Back 39

Largest of the plutons. Typically form within convergent plate zones and made of granite.

Front 40

Stocks (lacoliths)

Back 40

Small batholiths

Front 41

Dikes

Back 41

Plutons that cross-cut through layers of previously existing rocks. Fluids that melt their way through rocks and then crystallize in space. Younger than what they cut; usually silicic.

Front 42

Sills

Back 42

Plutons that form parallel to existing rock layers.

Front 43

Ocean crust:

Back 43

Basalt, Mafic dominated, very dense, Extrusive, thin and young.

Front 44

Continental crust:

Back 44

Granite dominated, but all petrologies; silicic dominated, light density, intrusive, thick and old (all ages present).