Chapter 3 Study Guide

rocks that crystallize out of magma

igneous

sedimentary

rocks that form from sediment

existing rocks that change

metamorphic

what is the source of igneous rocks

molten rock

cooling and crystallization of magma creates ___ rock

igneous

weathering and erosion creates ____

sediment

sediment accumulates by ____

deposition

_____ and ______ creates sedimentary rock

compaction and lithification

heat and pressure creates _____ rocks

metamorphic

forms below Earth’s surface when magma cools

intrusive/plutonic

_____ rocks tend to have larger crystals

intrusive or extrusive

intrusive

forms at earth’s surface when lava cools

extrusive

how are igneous rocks named (what is it based off of)

texture and composition

which type of texture:

no mineral grains (obsidian)

glassy

which type of texture:

grain size too fine to see with naked eye

very fine grained

which type of texture:

grain size up to 1 mm

fine grained

which type of texture:

grain size 1 to 5 millimeters

medium grained

which type of texture:

grain size more than 5 mm

coarse grained

which type of texture:

relatively large grains in a finer-grained matrix

porphyry

Granite and ____ are an example of intrusive/extrusive rock pairs

Rhyolite

Granite is _____

intrusive or extrusive

intrusive

does granite have big crystals or small

big

rhyolite is ____

intrusive or extrusive

extrusive

gabbro and ____ are an example of intrusive/extrusive rock pairs

basalt

gabbro is ____

intrusive or extrusive

intrusive

basalt is ____

intrusive or extrusive

extrusive

volcanic glass that forms when lava cools so quickly that crystals don’t have time to form

obsidian

obsidian is ____

intrusive or extrusive

extrusive

sedimentary rock made from pieces/fragments of pre-existing rocks

clastic

conglomerate, sandstone, siltstone and shale are examples of ____ sedimentary rocks

clastic or bioclastic

clastic

sedimentary rocks made primarily from biological material, such as shells or skeletal fragments

bioclastic

limestone is an example of ____ sedimentary rock

clastic or bioclastic

steps of sedimentary rock formation:

1. weathering

2. erosion

3. deposition

4. compaction

5. ______

lithification

sedimentary structure:

layers of sediment, tells us about change in sediment deposition

bedding

sedimentary structure:

layers are inclined/angled rather than horizontal, helps us determine direction of sediment transport/current or wind movement

cross-bedding

sedimentary structure:

small ridges and troughs on sediment, provide clues about direction and/or nature of the water flow

ripple marks

sedimentary structure:

cracks that form when wet mud dries out, they indicate that sediment was exposed to air and drying conditions

mud cracks

the alteration of an existing rock due to heat, pressure, and/or chemically active fluids without melting the rock

metamorphism

original rock before metamorphisis

protolith

degree/intensity of metamorphism a rock has experienced, depends on temp, pressure, duration/depth

metamorphic grade

low grade metamorphism means ____ alteration

more or less

less

true or false

during metamorphosis, minerals texture may recrystallize, grow larger, become aligned, rearrange

true

alignment of mineral into layers or bands due primarily to directed pressure

foliation

most widespread type of metamorphism, occurs over large regions, typically associated with convergent plate boundaries and mountain building

regional dyanothermal metamorphism

regional dyanothermal metamorphism commonly produce _____ metamorphic rocks

foliated

granite and rhyolite = _____

felsic or mafic

felsic

gabbro and basalt

felsic or mafic

mafic

type of metamorphism that occurs when existing rock is heated by a nearby magma intrusion

contact