Geology Exam #2

The movement of material by moving wind, water, or ice is a process called (1)________ whereas the process that breaks down solid rock into loose sediment is called (2)________. A. (1) mechanical weathering (2) chemical weathering B. (1) chemical weathering (2) mechanical weathering C. (1) erosion (2) weathering D. (1) weathering (2) erosion E. (1) deposition (2) weathering F. (1) weathering (2) deposition

C. (1) erosion (2) weathering

Which of the following are biochemical sedimentary rocks? SELECT THREE A. Coal B. Fossiliferous limestone C. Chalk D. Peat E. Shale F. Coquina G. Conglomerate H. Sandstone

B. fossiliferous limestone C. chalk F. coquina

Which of the following statements about metamorphism is FALSE? A. metamorphic rocks form from existing sedimentary, igneous, or metamorphic rocks B. metamorphism involves melting of existing rocks to form new minerals C. during metamorphism, existing minerals are transformed into new minerals D. metamorphism is controlled by pressure, temperature, fluids, and time E. metamorphic means "change of form" F. A protoliths metamorphoses into a metamorphic rock.

B. metamorphism involves melting of existing rocks to form new minerals

Index minerals are ______. A. Any minerals that grow in metamorphic rocks. B. Minerals that only form at certain temperatures/pressures. C. Minerals that help classify metamorphic rocks. D. Minerals that form at high pressure. E. Minerals that grow in magma F. Minerals found in foliated rocks.

B. minerals that only form at certain temperatures/pressures

A sedimentary bed contains three fossils: A, B, and C. Fossil A formed from an animal that only existed in the Cambrian and Ordovician Periods. Fossil B only existed in the Ordovician Period. Fossil C existed for a very long time on Earth- from the Cambrian to recent. Based on this fossil assemblage, the age of the rock is: A. Cambrian B. Ordovician C. Silurian D. sometime between the Cambrian and recent is all that we can tell E. impossible to determine

B. ordovician

What is the most common material found in sandstones? A. Feldspar B. Quartz C. Lithic fragments D. Chemical sediments E. Pebble F. Granule

B. quartz

When rock undergoes very high directed stress because of tectonism, the rock will be "squished" in one direction. This metamorphic process is called _____. A. contact metamorphism B. regional metamorphism C. shock metamorphism D. burial metamorphism E. fault metamorphism F. impact metamorphism

B. regional metamorphism

The result of differential stress on rocks can: A. cause the rocks to partially erode. B. cause new minerals to grow randomly in the protolith. C. cause mineral crystals to align parallel to each other. D. cause mineral crystals to dissolve. E. cause mineral crystals to melt. F. cause mineral crystals to shrink.

C. cause mineral crystals to align parallel to each other

The remains of sea organisms with shells made of silica accumulate on ocean bottoms as biogenic sediment that eventually forms a type of rock called: A. rock salt B. limestone C. chert D. fossiliferous limestone E. peat F. chalk

C. chert

Which of the following are examples of chemical weathering? SELECT ALL THAT APPLY A. Exfoliation B. Salt expansion C. Dissolution D. Frost wedging E. Hydrolysis F. Oxidation

C. Dissolution E. Hydrolysis F. Oxidation

What makes a shale different from a mudstone? A. Denser B. Darker colored C. Thinly bedded D. Different minerals E. Coarser grained F. Less dense

C. thinly bedded

Which of the soil horizons make up topsoil? A. O and E B. E and B C. A and B D. O and A E. E and A F. E and B

D. O and A

In stratigraphy, the principle of stratigraphic superposition states that: A. all sedimentary beds start off being horizontal B. all sedimentary beds are separated by bedding planes C. a sedimentary bed is younger than the bed above it and older than the bed below it D. a sedimentary bed is older than the bed above it and younger than the bed below it E. a sedimentary bed must be older than any feature that cuts through it or disrupts it F. a sedimentary bed is younger than any adjacent igneous rock

D. a sedimentary bed is older than the bed above it and younger than the bed below it.

Minerals like halite and calcite are particularly prone to chemical weathering through the process of dissolution. As a result, the following type of rock is prone to this type of weathering: A. limestone B. rock salt C. marble D. all of the above E. none of the above

D. all of the above

Into what category of sedimentary rocks does the type of rock fall that forms by the evaporation of water and consequent precipitation of minerals like halite? A. organic B. detrital C. clastic D. chemical E. biochemical F. none of the above

D. chemical

Hydrolysis reactions are when hydrogen ions in water replace mineral cations in the mineral crystal, forming a new mineral. This is how feldspars commonly break down to form: A. soil B. quartz C. olivine D. clay minerals E. feldspar fragments F. salt (halite)

D. clay minerals

In sedimentary rock types, the term clastic means the same thing as: A. chemical B. biochemical C. organic D. detrital E. lithic F. biogenic

D. detrital

An example of a trace fossil. Select all that apply: B. fossilized shells C. fossilized bones D. dinosaur footprint Fossil poop (coprolites) A. worm trails E. fossilized seeds

D. dinosaur footprint F. fossil poop (coprolites) A. worm trails

The protolith of marble is ______. A. Shale B. Quartzite C. Sandstone D. Limestone E. Mudstone

D. limestone

What is the most likely cause of a sediment with highly rounded grains? A. Stronger bedrock B. Shorter time since weathering C. Lack of water in environment D. Longer distance transported E. Higher temperatures in environment F. Glacial transport

D. longer distance transported

Match the sedimentary rock type conglomerate with the corresponding grain size below: A. clay B. silt C. mud D. pebble E. sand F. none of the above

D. pebble

What does a phase diagram show? A. Various minerals that are grouped in different metamorphisms B. Tectonic settings for different mineral phases C. Depositional environments for different mineral phases D. Pressure and temperature ranges at which different minerals form E. The progression of phases from low grade to high grade metamorphism F. Minerals that form in different terranes

D. pressure and temperature changes at which different minerals form

The protolith of slate is ______. A. granite B. limestone C. sandstone D. shale E. gneiss

D. shale

Sediment particles in quartz sandstone that formed in an eolian environment are typically: A. poorly sorted and angular B. poorly sorted and well rounded C. well sorted and angular D. well sorted and well rounded E. made of feldspar F. made of lithic fragments

D. well sorted and well rounded

Which of the following statements about sedimentary rocks is TRUE? A. sedimentary rocks only make up about 5% of the crust B. sedimentary rocks are the type of rock we see most often at the Earth's surface C. sedimentary rocks indicate the past environment D. the process of turning loose sediment into rock is called lithification E. all of the above F. none of the above

E. all of the above

Which of the following statements regarding lithostatic pressure is correct? A. it is caused by the weight of the overlying rocks B. it is equal in magnitude from all directions C. it causes rocks to decrease in volume but it does not change the rock shape D. it causes minerals to recrystallize E. all of the above F. none of the above

E. all of the above

When initially flat-lying beds get tilted and eroded, then new flat-lying beds get deposited on top, the type of unconformity that results is called a/an: A. paraconformity B. nonconformity C. nondepositional unconformity D. disconformity E. angular unconformity

E. angular unconformity

The correct combination of ripple shape and potential environment in which the ripple developed is: A. symmetric / single direction wind flow B. symmetric / river channels C. asymmetric / ocean waves D. asymmetric / beaches E. asymmetric / river channels F. none of the above is correct

E. asymmetric/ river channels

Which of the following pairs of words about sedimentary rocks belong together? A. detrital and evaporites B. chemical and pebbles C. biochemical and coal D. chemical and chalk E. detrital and sandstone F. clastic and chert

E. detrital and sandstone

Which of these fit polymorphism? A. Same mineral, different crystal structures B. Same mineral, different chemical formulas C. Same crystal structure, different chemical formulas D. Same crystal structure, different minerals E. Same composition, different crystal structures F. Same composition, different chemical formulas

E. same composition, different crystal structures

What is the number-one direct cause of changes in depositional environment? A. Rivers changing course B. Glaciers advancing and retreating C. Lakes swelling and evaporating D. Deserts migrating and growing E. Sea level rising and falling F. Earth changing its movements

E. sea level rising and falling

Which of these would likely produce the LEAST reliable absolute age of a rock from radiometric dating techniques? A. High-grade metamorphic rock B. Low-grade metamorphic rock C. Intrusive igneous rock D. Extrusive igneous rock E. Sedimentary rock

E. sedimentary rock

The global climate changes in geologic past resulted from: A. Rivers changing course B. Glaciers advancing and retreating C. Lakes swelling and evaporating D. Deserts migrating and growing E. Sea level rising and falling F. Earth changing its movements

F. earth changing its movements

The epoch that we currently live in is called the: A. Hologene B. Pleistocene C. Pliocene D. Miocene E. Paleocene F. Holocene

F. holocene

A foliation develops in a metamorphic rock because: A. platy minerals always align with each other during any type of metamorphism B. the original rock that got metamorphosed must have had a foliation in it C. directed stress causes minerals to align parallel to each other D. high temperatures during metamorphism always cause minerals to recrystallize with a foliation E. a platy form is the optimal shape when mineral crystals recrystallize F. this is what defines a metamorphic rock in the first place

C. directed stress causes minerals to align parallel to each other

Which of the following depositional environments has the least water? A. Fluvial B. Lacustrine C. Eolian D. Abyssal E. Paludal F. Littoral

C. eolian

Which of the following is the largest geologic time unit? A. Period B. Era C. Eon E. Epoch F. Age

C. eon

The type of sedimentary structure that describes a layer of sediment in which the grain size steadily decreases from the bottom to the top of the layer is called: A. bedding B. cross bedding C. graded bedding D. ripple marks E. Imbrication F. Lamination

C. graded bedding

Which of these would likely produce the most reliable absolute age of formation from radiometric dating techniques? A. High-grade metamorphic rock B. Low-grade metamorphic rock C. Igneous rock D. Clastic sedimentary rock E. Chemical sedimentary rock F. Sediments

C. igneous rock

Heat promotes recrystallization by __________. A. separating ultramafic elements from mafic ones B. causing minerals to melt C. increasing atomic vibration D. stripping away electrons E. adding catalysts to reactions F. increasing pressure

C. increasing atomic vibration

What materials were used to determine the age of the Earth? A. Samples of oceanic crust B. Zircons from the oldest continental crust C. Meteorites D. Gneisses from the oldest continental crust E. Rock samples from the outer core F. Rock samples from the mantle

C. meteorites

Which of these indicate changing water conditions, from wet to dry, in an arid land? A. Graded bedding B. Cross bedding C. Mudcracks D. Ripple marks E. Bioturbation

C. mudcracks

Match the sedimentary rock type arkose with the corresponding grain size below: A. clay B. silt C. sand D. pebble E. boulder F. none of the above

C. sand

A sedimentary bed contains three fossils: A, B, and C. Fossil A formed from an animal that only existed in the Ordovician and Silurian Periods. Fossil B only existed in the Silurian Period. Fossil C existed for a very long time on Earth- from the Cambrian to recent. Based on this fossil assemblage, what must the age of the rock be? A. Cambrian B. Ordovician C. Silurian D. sometime between the Cambrian and recent is all that we can tell E. it's impossible to tell

C. silurian

A typical feature of the sediment particles in glacially produced tillite is that they: A. are poorly sorted and angular B. are poorly sorted and well rounded C. are well sorted and angular D. are well sorted and well rounded E. are fine grained F. thinly laminated

A. are poorly sorted and angular

Which of the following are part of the process of diagenesis? SELECT ALL THAT APPLY A. Cementation B. Compaction C. Recrystallization D. Crystallization E. Melting F. Deposition

A. cementation B. compaction C. recrystallization

Which of the following are part of the process of lithification? SELECT ALL THAT APPLY A. Cementation B. Compaction C. Recrystallization D. Crystallization E. Melting F. Deposition

A. cementation B. compaction F. deposition

Which of the following are index minerals? SELECT ALL THAT APPLY A. Chlorite B. Garnet C. Quartz D. Kyanite E. Staurolite F. Biotite

A. chlorite B. garnet D. kyanite E. staurolite F. biotite

Match the sedimentary rock type shale with the corresponding grain size below: A. clay B. silt C. sand D. pebble E. boulder F. none of the above

A. clay

What type of metamorphism results in the development of an aureole? A. contact metamorphism B. regional metamorphism C. shock metamorphism D. burial metamorphism E. fault metamorphism F. impact metamorphism

A. contact metamorphism

When magma intrudes pre-existing country rock, the rock will be cooked by the magma. This metamorphic process is called _____. A. contact metamorphism B. regional metamorphism C. shock metamorphism D. burial metamorphism E. fault metamorphism F. impact metamorphism

A. contact metamorphism

Which of the following directly causes sinkholes? A. dissolution B. frost wedging C. salt expansion D. exfoliation E. hydrolysis F. oxidation

A. dissolution

A bed with a mix of sandstone and conglomerate sedimentary rocks with ripple marks, cross beds, and leaf fossils likely formed in which depositional environment? A. Fluvial B. Alluvial C. Paludal D. Eolian E. Glacial F. Abyssal

A. fluvial

Which of the following types of metamorphic rocks is NOT foliated? A. hornfels B. gneiss C. slate D. phyllite E. schist

A. hornfels

Why is the mineral zircon good for absolute dating? SELECT ALL THAT APPLY A. It is durable B. It contains uranium C. It reacts easily D. It contains potassium E. It forms in all igneous rocks F. It is widespread.

A. it is durable B. it contains uranium

Which of the following depositional environments are characterized by fine-grained sediment (mud)? SELECT ALL THAT APPLY A. Lacustrine B. Alluvial C. Abyssal D. Eolian E. Fluvial F. Glacial

A. lacustrine C. abyssal

Why are fossils so uncommon in older rocks? A. Life had not developed hard body parts yet B. Early organisms were so small that the fossils are hardly discovered C. Fossilized early organisms resemble mineral grains D. The older rocks that include fossils are too deep in the crust to collect and study E. Early organisms were not widespread enough to be found

A. life had not developed hard body parts yet

Which of the following forms of weathering does NOT involve a mechanical weathering process? SELECT ALL THAT APPLY A. oxidation B. frost wedging C. salt expansion D. exfoliation E. root wedging F. Dissolution

A. oxidation F. dissolution

About 540 million years ago, the _____. SELECT ALL THAT APPLY A. Proterozoic ended B. Precambrian ended C. Paleozoic began D. Phanerozoic began E. Paleogene began F. Mesozoic ended

A. proterozoic ended b. precambrian ended c. paleozoic began d. phanerozoic began

Which of the following metamorphic rocks does not belong in the same list as the others? A. quartzite B. schist C. phyllite D. gneiss E. slate

A. quartzite

Which of these can indicate a paleocurrent direction? SELECT ALL THAT APPLY A. Ripple marks B. Mudcracks C. Imbrication D. Cross bedding E. Raindrop impressions F. Bioturbation

A. ripple marks C. imbrication D. cross bedding

Which sequence list shows metamorphic rocks in order from low-grade to high-grade? A. slate→phyllite→schist→gneiss B. slate→phyllite→gneiss→schist C. phyllite→slate→schist→gneiss D. schist→slate→gneiss→phyllite E. gneiss→schist→slate→phyllite F. gneiss→schist→phyllite→slate

A. slate→phyllite→schist→gneiss

Which of the soil horizons make up humus? A. the O horizon B. the E horizon C. the A horizon D. the B horizon E. the O and A horizons F. the A and E horizons

A. the O horizon

If we see a sedimentary bed that has a fault cutting through it as well as a dike that cuts through both the bed and the fault, we can use the principle of cross-cutting relationships to infer: A. the bed formed first, then the fault, then the dike B. the bed formed first, then the dike, then the fault C. the fault formed first, then the bed, then the dike D. the fault formed first, then the dike, then the bed E. the dike formed first, then the bed, then the fault F. the dike formed first, then the fault, then the bed

A. the bed formed first, then the fault, then the dike

What are the components of soil? SELECT ALL THAT APPLY A. Weathered rock B. Unweathered rock C. Eroded rock D. Organic material (humus) E. Water F. Air G. Regolith

A. weathered rock D. organic material (humus) E. water F. air G. regolith

What are the characteristics of an index fossil? A. Widespread geographically, chronologically limited B. Localized geographically and chronologically C. Widespread geographically and chronologically D. Localized geographically, chronologically widespread E. The most representative fossils in an area F. The most representative fossils in a geologic time

A. widespread geographically, chronologically limited

Which of the following statements about radioactivity is FALSE? SELECT ALL THAT APPLY A. radioactive dating is a technique of relative dating B. all isotopes of an element have the same number of neutrons and different numbers of protons C. in radioactive decay, daughter isotopes turn into parent isotopes D. all isotopes of an element have the potential to undergo radioactive decay E. the amount of parent isotopes is always increasing F. all available atoms of an unstable isotope will fully decay after two half-lives

All answers are false.

If the half-life of an isotope is 1 million years, and 100 of the isotope are in an igneous rock when it first forms, how old will the rock be when there are only 25 of these isotopes left in the crystal? (If this question is on the exam, some numerical values will be modified, but they remain as simple so that you do not need a calculator.) A. 1 million years old B. 2 million years old C. 3 million years old D. 4 million years old E. 5 million years old F. 25 million years old

B. 2 million years old

What mainly causes agents of transport, like wind or water, to deposit sediment? A. Increases speed B. Decreased speed C. Increased temperature D. Decreased temperature E. Increased weathering F. Decreased weathering

B. Decreased speed

A rock stratum is tiled noticeably from horizontal. What is the most reasonable conclusion you can draw? A. The stratum was deposited on the angle of the continental slope B. A tectonic event has occurred in the area since deposition of the stratum C. A meteorite struck that region, and the stratum is bowed up near the margin of the crater D. A volcano punched through the region deforming the stratum E. The layers have slowly rotated as the ground around them has been compressed with lithification F. Erosion removed the base strata, tilting the overlying strata.

B. a tectonic even has occurred in the area since deposition of the stratum

Which of the following statements about radioactivity is FALSE?: SELECT ALL THAT APPLY A. the rate of decay of an isotope never changes B. the amount of daughter isotopes is always decreasing C. all isotopes of any element decay D. all isotopes have the same half-life value E. decay rates are affected by the physical and chemical environment F. one half of the available unstable isotopes always decays during one half-life

B. the amount of daughter isotopes is always decreasing C. all isotopes of any element decay D. all isotopes have the same half-life value E. decay rates are affected by the physical and chemical environment

If we see a sedimentary bed that has a dike cutting through it as well as a fault that cuts through both the bed and the dike, we can use the principle of cross-cutting relationships to infer: A. the bed formed first, then the fault, then the dike B. the bed formed first, then the dike, then the fault C. the fault formed first, then the bed, then the dike D. the fault formed first, then the dike, then the bed E. the dike formed first, then the bed, then the fault F. the dike formed first, then the fault, then the bed

B. the bed formed first, then the dike, then the fault