Rocks
Fill in the Blanks
coarse extrusive extrusive fine gabbro granite igneous igneous intrusive lava magma Marble metamorphic metamorphic Sandstone Schist sedimentary sedimentary sediments Shale
The three major classes of rocks are
,
, and
. Molten rock material is called
. Rocks which have formed from the cooling and solidification of molten material are
rocks. Magma that reaches the surface of the earth still molten (that is, erupts out of a volcanic vent) is called
, or
igneous rock. Magma which cools and solidifies below the earth's surface is
igneous rock, also called plutonic rock.
Extrusive igneous rock is generally
-textured (choose fine- or coarse-), because it cools so rapidly that there is little time for crystals to form. Intrusive igneous rock is
-textured (choose fine- or coarse-), because it cools slowly, so large mineral crystals may form.
Loose particles that result from the weathering of pre-existing rocks, or from chemical action or an accumulation of organic material, are called
. When such particles lithify to form rocks owing to pressure or chemical cementation, the rocks belong to the major rock class called
rocks.
Rock which has been changed into a different rock as a result of heat and/or pressure (but not enought heat to completely melt the rock) is called
rock.
Basalt is an
(extrusive or intrusive) igneous rock ciomposed of minerals high in iron and magnesium. The plutonic rock with a similar composition but a coarse-grained texture is
. Rhyolite is a fine-grained volcanic rock high in quartz and feldspars. The plutonic rock with a similar composition, but a coarse-grained texture is
.
is a sedimentary rock formed from compacted sand grains.
is a sedimentary rock formed from fine-grained clay and silt particles.
is a metamorphic rock usually derived from limestone.
is a foliated metamorphic, with very thin layers of platy materials such as mica.
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