Minerals and Rocks (2)
Classifying rocks as igneous, sedimentary, or metamorphic is based upon differences in their
Origin
Rocks that would most likely be SEPARATED by a zone of METAMORPHIC rock are
Granite and limestone
Magnesium, iron, and aluminum
A group of elements is listed in increasing order based on the percent by mass in Earth's crust
Some of the oldest rocks in NY are Precambrian marbles. The predominant minerals that make up these rocks are white or pink in color and bubble when exposed to hydrochloric acid. What are the minerals that make up these marbles?
Calcite
Acid rain reacting with limestone bedrock is an example of
Chemical Weathering
Which PROPERTY of minerals is illustrated by an internal arrangement of atoms such as the peeling of biotite mica into thin flat sheets?
Cleavage
If you observe a wide variety of samples of quartz, which property is likely to change the most, from sample to sample, because of minor impurities?
Color
What PROCESSES can change SEDIMENTS INTO SEDIMENTARY ROCKS?
Compaction and cementation
HEAT and PRESSURE due to MAGMA INTRUSIONS may result in
Contact metamorphism
What causes MOLTEN ROCK material to become GLASSY igneous rock?
Cooling on earth's surface
Dolostone and rock gypsum are formed by the processes of
Erosion and deposition of clastic fragments
What is the NAME of the IGNEOUS rock that has crystallized deep below Earth's surface and has the following composition: 70 percent pyroxene, 15 percent plagioclase feldspar, and 15 percent olivine?
Gabbro (ERST)
Which rock is usually composed of SEVERAL different minerals?
Gneiss
Which property is MOST USEFUL in mineral identification?
Hardness
The minerals of many METAMORPHIC rocks are aligned in bands as a result of
Heat and pressure
What is ONE difference between the metamorphic rocks QUARTZITE and HORNFELS?
Hornfels is produced by contact metamorphism; quartzite is produced by regional metamorphism
In what part of New York State would you most likely find large amounts of bedrock formed by REGIONAL METAMORPHISM?
Hudson Highlands and Adirondack Mountains
Garnet is the state mineral of New York. A variety of garnet called almandine is found in the gneisses of the Gore Mountain region of New York State. How did this mineral form?
It formed when heat and pressure changed existing materials
How does the RATE of COOLING affect the SIZE of mineral crystals?
Large, well-formed minerals are the result of a slow rate of cooling
What rock is commonly composed of the REMAINS of ANIMAL SHELLS?
Limestone
What type (or types) of rock is (are) usually HEATED as part of its (their) formation?
Metamorphic and igneous rocks
A rock made of the SHELLS of MARINE ORGANISMS should be classified as
Organic sedimentary rock
The difference between REGIONAL METAMORPHISM and CONTACT METAMORPHISM is
Regional metamorphism has a larger amount of space than contact metamorphism
What kinds of IGNEOUS ROCKS have the SAME mineral composition?
Rhyolite and granite
What SEDIMENTARY rock would be formed from PARTICLES 2 to 4 centimeters in diameter cemented by a FINE-GRAINED MATRIX?
Sandstone (ERST)
What kind of METAMORPHIC ROCK usually contains abundant MICA CRYSTALS and a FOLIATED TEXTURE?
Schist
What SEDIMENTARY rocks are CLASTIC and consist of particles that have diameters smaller than 0.006 centimeters?
Siltstone and shale
A YELLOW mineral is found near the mouth of a hot spring. IT has a ROTTEN EGG SMELL and a CLEAR STREAK. It also shows FRACTURE. What is the mineral?
Sulfur
What characteristic would indicate that a rock was formed from sediments deposited in shallow water near shore rather than in deep water?
a large grain size
Generally, as the percentage of of fells minerals in a rock increases, the rock's color will become
darker and the density will decrease
Compared with basalt, granite is
darker in color
The BIGGEST DIFFERENCE between a sedimentary rock and metamorphic rock is
environment of formation
The longer time that it takes a rock to solidify, the
larger the crystals will be
Only a small number of Earth's minerals are commonly found in rocks. This fact indicates that most
rocks have a number of minerals in common