ESS 101 B Lab 5 EXAM- updated with
detailed questions and A+ rated accurate
answers
How are metamorphic rocks formed? - CORRECT ANSWER Metamorphic rocks are
created by the physical or chemical alteration by heat and pressure of an existing
igneous or sedimentary material into a denser form. ... In some cases, heat from the
Earth's interior can melt the rock slightly, in a process termed "contact metamorphism."
Would chemical or mineral composition be more important for identifying the protolith of
a metamorphic rock before metamorphism? - CORRECT ANSWER The chemical
composition
Would pressure or temperature composition be more important for identifying the
protolith of a metamorphic rock before metamorphism? - CORRECT ANSWER
Mineralogical changes during metamorphism of the sedimentary rock shale. Note that
the elemental composition will not change, but the mineral composition will reflect the
pressure/temperature condition.
What happens to the grain size of crystals as a rock gets more and more
metamorphosed? - CORRECT ANSWER The change in the particle size of the rock
during the process of metamorphism is called recrystallization. For instance, the small
calcite crystals in the sedimentary rock limestone and chalk change into larger crystals
in the metamorphic rock marble; in metamorphosed sandstone, recrystallization of the
original quartz sand grains results in very compact quartzite, also known as
metaquartzite, in which the often larger quartz crystals are interlocked. Both high
temperatures and pressures contribute to recrystallization. High temperatures allow the
atoms and ions in solid crystals to migrate, thus reorganizing the crystals, while high
pressures cause solution of the crystals within the rock at their point of contact.
What is a half-life of a radioactive isotope? - CORRECT ANSWER The rate at which a
radioactive isotope decays is measured in half-life. The term half-life is defined as the
time it takes for one-half of the atoms of a radioactive material to disintegrate. Half-lives
for various radioisotopes can range from a few microseconds to billions of years.
What is the law of cross-cutting relations? - CORRECT ANSWER Cross-cutting
relationships is a principle of geology that states that the geologic feature which cuts
another is the younger of the two features. It is a relative dating technique in geology.
What happens during metamorphism that can make us numerically date a metamorphic
rock incorrectly? - CORRECT ANSWER Erosion can remove layers, etc.
detailed questions and A+ rated accurate
answers
How are metamorphic rocks formed? - CORRECT ANSWER Metamorphic rocks are
created by the physical or chemical alteration by heat and pressure of an existing
igneous or sedimentary material into a denser form. ... In some cases, heat from the
Earth's interior can melt the rock slightly, in a process termed "contact metamorphism."
Would chemical or mineral composition be more important for identifying the protolith of
a metamorphic rock before metamorphism? - CORRECT ANSWER The chemical
composition
Would pressure or temperature composition be more important for identifying the
protolith of a metamorphic rock before metamorphism? - CORRECT ANSWER
Mineralogical changes during metamorphism of the sedimentary rock shale. Note that
the elemental composition will not change, but the mineral composition will reflect the
pressure/temperature condition.
What happens to the grain size of crystals as a rock gets more and more
metamorphosed? - CORRECT ANSWER The change in the particle size of the rock
during the process of metamorphism is called recrystallization. For instance, the small
calcite crystals in the sedimentary rock limestone and chalk change into larger crystals
in the metamorphic rock marble; in metamorphosed sandstone, recrystallization of the
original quartz sand grains results in very compact quartzite, also known as
metaquartzite, in which the often larger quartz crystals are interlocked. Both high
temperatures and pressures contribute to recrystallization. High temperatures allow the
atoms and ions in solid crystals to migrate, thus reorganizing the crystals, while high
pressures cause solution of the crystals within the rock at their point of contact.
What is a half-life of a radioactive isotope? - CORRECT ANSWER The rate at which a
radioactive isotope decays is measured in half-life. The term half-life is defined as the
time it takes for one-half of the atoms of a radioactive material to disintegrate. Half-lives
for various radioisotopes can range from a few microseconds to billions of years.
What is the law of cross-cutting relations? - CORRECT ANSWER Cross-cutting
relationships is a principle of geology that states that the geologic feature which cuts
another is the younger of the two features. It is a relative dating technique in geology.
What happens during metamorphism that can make us numerically date a metamorphic
rock incorrectly? - CORRECT ANSWER Erosion can remove layers, etc.
