7th Science Ch. 3
A rock is always _____.
a mixture of minerals, organic matter, volcanic glass, or other materials
Quartz is a mineral; granite is _____.
a rock
An igneous rock can form from _____ magma.
basaltic; andesitic; grantic
The process in which minerals hold sediment together, like glue, making a detrital sedimentary rock.
cementation
a kind of organic sedimentary rock
coal
The process in which pressure from the upper layers of sediment pushes down on the lower layers, causing the sediments to stick together and form solid rock.
compaction
Sandstone is a(n) _____ sedimentary rock.
detrital
Sedimentary rocks formed from broken fragments of other rocks are _____.
detrital
the movement of weathered material
erosion
When lava cools at Earth's surface, _____ igneous rocks are formed.
extrusive
Lava that cools quickly forms _____ rocks.
extrusive igneous
Metamorphic rocks that show layers of dark minerals alternating with layers of light minerals are classified as _____.
foliated
A classification of metamorphic rocks would include whether they are _____.
foliated or nonfoliated
Sedimentary rocks are _____.
formed when loose materials become pressed or cemented together or when minerals form from solutions
Sediments in sedimentary rocks are often _____.
held together with natural cements
Granite is a(n) _____ rock.
igneous
Obsidian is a(n) _____
igneous
When magma cools deep inside Earth, _____ igneous rocks are formed.
intrusive
Magma from deep inside Earth rises toward the surface because _____.
it is less dense than surrounding solid rock
The crystals that form in slowly cooled magma produce _____ mineral grains.
large
Foliated rocks are distinguished by _____.
layers
a kind of chemical sedimentary rock
limestone
Detrital rocks are _____.
made from broken fragments of other rocks.
The molten material deep inside Earth from which igneous rocks form is called _____.
magma
Igneous rocks form from _____ when it cools.
magma; lava
a kind of nonfoliated metamorphic rock
marble
Changes that take place in rocks never create or destroy _____.
matter
Gneiss is a(n) _____ rock.
metamorphic
Slate is a(n) _____ rock.
metamorphic
Sedimentary rocks formed from the remains of once-living things are _____.
organic
The pressure and heat that produce magma are caused in part by _____.
radioactive elements
Basaltic igneous rocks are _____.
rich in iron and magnesium
Limestone is a(n) _____ rock.
sedimentary
Rock salt is a(n) _____ rock
sedimentary
Sandstone is a(n) _____ rock.
sedimentary
a kind of foliated metamorphic rock
slate
A detrital rock is named according to _____.
the shape and size of the sediments
The process in which rock is exposed to air, water, or ice and breaks into pieces.
weathering
