Chapter 4 (Rocks) Flashcards
Mixture of one or more minerals, rock fragments, volcanic glass, organic matter, or other natural materials; can be igneous, metamorphic or sedimentary
Rock
model that describes how rocks slowly change from one form to another through time.
Rock Cycle
Rock formed when magma or lava cools and hardness.
Igneous Rock
Molten rock that flows from volcanos onto earth’s surface.
Lava
Describes a type of igneous rock that generally contains large crystals and forms when magma cools slowly beneath the earth’s surface.
Intrusive rocks
Describes fine grain igneous rock when magma cools quickly at or near the earth’s surface.
Extrusive rocks
Igneous rocks that are dense, dark-colored rocks.
They form from magma that is rich in iron and magnesium and poor in silica.
Basaltic rocks
Igneous rocks that are light-colored rocks of a lower density than basaltic rocks. The magma from this rock is thick and stiff and contains lots of silica but lesser amounts or iron and magnesium.
Granitic rocks
Rocks that have mineral compositions between this of basaltic and granitic rocks. Many volcanos around the rim of the Pacific Ocean formed from this type of magmas.
Andesitic rocks
Pumice, obsidian and scoria are some examples of this type of rock. These rocks cooled so quickly that few or no mineral grains formed.
Volcanic glass
Rocks that have changed because of changes in temperature and pressure or the presence of hot, watery fluids.
These rocks can form from igneous, sedimentary or others.
Metamorphic rocks
Types of metamorphic rocks.
Foliated rocks and
Nonfoliated rocks
metamorphic rocks such as gneiss, and slate which have a layered or banded appearance that is produced by exposure to heat and high pressure
Foliated rocks
metamorphic rocks such as marble and quartzite which DO NOT have a layered or banded appearance.
Nonfoliated rocks
Changes in pressure, temperature, or the presence of fluids can cause _______________ rocks to form
Metamorphic
True or False
Rock, altered by metamorphic processes at high temperatures and pressures, changes in the solid state and starts melting
False
Rock, altered by metamorphic processes at high temperatures and pressures, changes in the solid state WITHOUT melting
Hot fluids that move through and react with preexisting rock are composed mainly of ___________ and ____________
Water and Carbon dioxide
True or false
Any PARENT rock type —- igneous, or sedimentary —- can become a metamorphic rock.
True
loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice or gravity.
Sediments
Rocks formed when sediments are pressed and cemented together, or when minerals form from solutions
sedimentary rock
Sedimentary rocks classification
DETRITAL
CHEMICAL
ORGANIC
These rocks consist of sediment grains derived from the weathering and erosion of other rocks. They are by far the most abundant of the sedimentary rocks. Common ————— rocks are shale, sandstone and conglomerate.
DETRITAL SEDIMENTARY ROCKS
the name “detritus” (Latin for loose material derived from disintegration).
These rocks are composed mostly of mineral crystals that form and settle (precipitate) from water, either lakes, the ocean, or groundwater. They are extremely valuable to industry. Common chemical rocks are rock salt, rock gypsum and chemical limestone.
CHEMICAL SEDIMENTARY ROCKS
These rocks contain significant amounts of biologic material, usually in the form of fossil fragments that were originally deposited on the ocean floor. Examples of such rocks are coquina and chalk, which are types of limestones. Heating of organic material can cause it to slowly alter into useful forms of petroleum. Examples of such rocks are oil shale and coal.
ORGANIC SEDIMENTARY ROCKS
