Chapter 10 Review Questions and Answers

Multiple Choice Questions

   1.    The geologic history of the North American craton can be divided into two parts, which are

A.  greenstone belt development and accretion

B.   mountain building and shallow transgressive and regressive seas

C.  transgressive and regressive mountain building

D.  deep ocean basins and granite magmatism

E.   none of the above

Answer:  B

 

   2.    The presumed causes for transgressions and regressions of shallow seas during the Paleozoic were

A.  greenhouse effect and glaciation

B.   tectonic activity and continental rifting

C.  glaciation and tectonic events

D.  bolide impact and glaciation

E.   none of the above

Answer:  C

 

   3.    Each of the major continents at the beginning of the Paleozoic can be divided into two major components:

A.  a trough and a range

B.   a craton and a mobile belt

C.  an immobile belt and a rift margin

D.  a craton and a ocean basin

E.   none of the above

Answer:  B

 

   4.    The craton can be subdivided into

A.  a mobile belt and a sub-craton

B.   a sub-craton and a platform

C.  a platform and a mobile belt

D.  a shield and a platform

E.   none of the above

Answer:  D

 

   5.    The Michigan Basin is an important source for

A.  rock salt

B.   anhydrite and gypsum

C.  oil

D.  gas

E.   all of the above

          Answer:  E

 

 

   6.    Rocks of the shield are primarily

A.  igneous

B.   metamorphic

C.  sedimentary

D.  A and C

E.   A and B

Answer:  E

 

 7.      On the surface, the platform is characterized by

A.  flat-lying to gently dipping Paleozoic sedimentary rocks

B.   steeply dipping and folded Paleozoic sedimentary rocks

C.  folded and faulted Precambrian metamorphic rocks

D.  A and C

E.   none of the above

Answer:  A

 

   8.    Which of the following was not a mobile belt affecting the North American continent during the Early Paleozoic?

A.  Franklin

B.   Cordilleran

C.  Hercynian

D.  Ouachita

E.   Appalachian

Answer:  C

 

   9.    Areas of elongate mountain building activity are called

A.  shields

B.   mobile belts

C.  platforms

D.  basins

E.   A & B

Answer:  B

 

10.    During the Cambrian, most of the continents were

A.  together in one landmass

B.   dispersed around polar regions

C.  dispersed in low latitude regions

D.  covered by ice

E.   regions of extreme volcanic activity

Answer:  C

 

 

 

 

 

 

11.    Plate movement in the Ordovician and Silurian resulted in

A.  movement of Gondwana to a south polar region

B.   development of an active eastern margin on Laurentia

C.  collision of Baltica and Laurentia

D.  Siberia and Kazakhstania migrating to north temperate regions

E.   all of the above

Answer:  E

 

12.    In the Cambrian, the major event for the North American continent was

A.  epeiric sea transgression and regression

B.   eastern and western orogenic activity

C.  volcanic activity

D.  emplacement of plutons along the southern margin

E.   all of the above

Answer:  A

 

13.    Extremely large scale lithostratigraphic units bounded by transgressive-regressive unconformities are called

A.  cratonic sequences

B.   mobile belts

C.  facies

D.  supergroups

E.   cratonic unconformities

Answer:  A

 

13.    On the North American continent, how many cratonic sequences have been recognized?

A.  3

B.   4

C.  6

D.  8

E.   10

Answer:  C

 

14.    A cratonic sequence is recognized by

A.  transgressive phase followed by regressive phase

B.   regressive phase followed by a transgressive phase

C.  only a regressive phase

D.  only a transgressive phase

E.   none of the above

Answer:  A

 

 

 

 

 

15.    Global transgressive and regressive cycles can be caused by

A.  major tectonic events

B.   meteorite impact

C.  unusual lunar tidal cycles during early formation of Moon

D.  major glacial events

E.   A and D

Answer:  E

 

16.    The study of rock relationships within a time-stratigraphic framework of related facies bounded by unconformities is called

A.  stratigraphy

B.   sequencing

C.  sequence stratigraphy

D.  stratigraphic sequencing

E.   none of the above

Answer:  C

 

17.    A succession of rocks bounded by unconformities and their equivalent conformable strata is called a

A.  facies

B.   time-bound facies

C.  lithostratigraphic facies

D.  sequence

E.   lithosequence facies

Answer:  D

 

18.    Sequence stratigraphy is based on

A.  lithostratigraphic horizons

B.   time-stratigraphic boundaries to related units

C.  no lithologic variation in a stratigraphic sequence

D.  fossil correlations

E.   radiometric dating

Answer:  B

 

19.    Sequence boundaries form as a result of

A.  relative drop in sea level

B.   relative rise in sea level

C.  global climate change

D.  global atmospheric change

E    none of the above

Answer:  A

 

 

 

 

 

20.    Limestone structures made of the skeletal structures of living organisms are

A.  inorganic colonies

B.   organic reefs

C.  organic colonials

D.  inorganic reefs

E.   None of the above.

Answer:  B

 

21.    Organic reefs are useful paleoecological indicators because modern reef builders only

A.  form limestone reefs in cold, tropic waters

B.   form limestone reefs where there is a great abundance of mineral matter in the water

C.  only form limestone reefs in warm, clear, shallow water

D.  only form limestone reefs between 30 degrees north and south of the equator

E.   C and D

Answer:  E

 

22.    Reefs typically form

A.  as a build-up along a beach

B.   circular features in deep basins

C.  linear masses that separate a shallow platform from deep marine environment

D.  only in high turbulence, wave zones

E.   none of the above

Answer:  C

 

23.    Reefs first appeared in the geologic record in great abundance during the

A.  Cambrian

B.   Early Ordovician

C.  Late Proterozoic

D.  Late Ordovician

E.   Late Devonian

Answer:  D

 

24.    All of the following played a role in development of thick evaporite sequences in reef-fringed basins except

A.  rise in sea level after reef formation

B.   upward growth of the reef

C.  drop in sea level after reef formation

D.  evaporation

E.   restriction of circulation

Answer:  A

 

 

 

 

25.    The Tippecanoe Sea had retreated to the craton margin by the

A.  Late Ordovician

B.   Silurian

C.  Late Devonian

D.  Early Devonian

E.   Early Ordovician

Answer:  D

 

26.    The Taconic orogeny that began in the _______ _______ can be related to _______

A.  Middle Carboniferous, closing of Iapetus

B.   Late Ordovician, opening of Iapetus

C.  Middle Ordovician, closing of Iapetus

D.  Middle Ordovician, collision of North America and Gondwana

E.   Silurian, collision of North America and Australia

Answer:  C

 

27.    The onset of mountain building in the Appalachian mobile belt is characterized by all of the following except

A.  platform carbonate deposition

B.   thin bedded black shales

C.  coarse sandstones

D.  graywackes

E.   volcanic rocks

Answer:  A

 

28.    Which of the following is evidence for the Taconic orogeny?

A.  angular unconformities between Ordovician and Silurian rocks

B.   volcanic activity and intrusive igneous bodies

C.  regional metamorphism

D.  clastic wedge deposits

E.   all of the above

Answer:  E

 

29.    The Queenston Delta formed in response to

A.  erosion of the Taconic Highlands

B.   subduction of the Iapetus plate

C.  uplift of the Caledonides

D.  carbonate deposition on a passive margin

E.   delta deposition of a Paleozoic fluvial system

Answer:  A

 

 

 

 

 

 

30.    All but which are examples of Early Paleozoic mineral deposits

A.  silica sand

B.   rock salt and anhydrite

C.  lead and zinc

D.  iron

E.   chromite

Answer:  E

 

31.    The basal unit of the Tippecanoe sequence is an important source for

A.  lime

B.   copper

C.  aluminum

D.  silica sand

E.   iron

Answer:  D

 

32.    The Silurian Clinton Formation is an important source for

A.  rock salt

B.   oil and gas

C.  iron

D.  silica

E.   lime

Answer:  C

 

33.    Lead and zinc deposits in Missouri are found in Paleozoic rocks of this period:

A.  Cambrian

B.   Mississippian

C.  Ordovician

D.  all of the above

E.   A & C

Answer:  D

 

34.  The first mountain building episode of the Appalachians was the

         A. Acadian orogeny

         B. Caledonian orogeny

         C. Franklin orogeny

         D. Ouachita orogeny

         E. Taconic orogeny

         Answer:  E

 

 

 

 

 

 

 

35.  The first reef builders of the Paleozoic were the

         A. archaeocyathids

         B. bryozoans

         C. corals

         D. stromatoperoids

         E. All of the above

         Answer:  A

 

36.  The geologist responsible for developing sequence stratigraphy is

         A.  Darwin

         B.  Hutton

         C.  Sloss

         D. Taconic

         E. Wallace

         Answer: C

 

37.  In the Ordovician, carbonate reef deposition resulted from

         A. chemical precipitation in a saturated lake

         B. calcium carbonate secreting organisms

         C. formation of ooids in a deep sea environment

         D. evaporation within a shrinking continental basin

         E.  A & C

         Answer:  B

 

38. A primary difference between limestone and dolostone is

         A. limestone has a higher magnesium content

         B. dolostone has a higher magnesium content

         C. dolostone has been metamorphosed

         D. limestone is a carbonate mineral

         E. dolostone is a carbonate mineral

         Answer:  B

 

39.  Of the following, which is the mineral first precipitated when seawater evaporates?

         A. calcium carbonate

         B. dolostone

         C. gypsum

         D. halite

         E. It depends upon the composition of the seawater.

         Answer:  A

 

 

 

 

 

 

 

40.  The basin within the Tippecanoe Sequence in which evaporites precipitated is the

         A. Cordilleran

         B. Michigan

         C. Ouachita

         D. Taconic

         E. Williston

         Answer:  B

 

True-False Questions

   1.    _______  During the Paleozoic Era, cratons were covered with large bodies of water called epeiric seas. (T)

 

   2.    _______  The rise and fall of sea level in epeiric seas could be directly correlated with changes of Moon-Earth distance relations. (F)

 

   3.    _______  Mobile belts form when convergent plate margins develop. (T)

 

   4.    _______  Rise and fall of sea level in epeiric seas can be partly explained by continental glaciation events. (T)

 

   5.    _______  The Appalachian and Ouachita mountains represent ancient mobile belts. (T)

 

   6.    _______  Platform sedimentary rocks are entirely carbonate rocks. (F)

 

   7.    _______  Paleogeographic maps reconstruct what Earth looked like at a given time in the past. (T)

 

   8.    _______  Paleogeographic reconstructions are based only on paleomagnetic data. (F)

 

   9.    _______  Reconstruction of Paleozoic paleogeography is well documented by magnetic stripe data from rocks 600 to 250 million years old on the ocean floor. (F)

 

10.    _______  Paleozoic paleogeographic reconstructions are based primarily on structural relations, sedimentary facies, and fossil distribution. (T)

 

11.    _______  At the beginning of the Paleozoic there were eight major continents. (F)

 

12.    _______  At the beginning of the Cambrian, all of the continents were dispersed in high latitude regions of the globe. (F)

 

13.    _______  The presence of tillites in Upper Ordovician age rocks found in the modern Sahara indicates that the paleocontinent of Gondwana was once closer to the South Pole. (T)

 

14.    _______  Mesozoic and Cenozoic paleogeographic reconstructions are more accurate than those for the Paleozoic because magnetic anomaly patterns for Mesozoic and Cenozoic age rocks are better preserved in ocean crust. (T)

 

15.    _______  The first major transgression onto the craton during the Paleozoic was the Tippecanoe. (F)

 

16.    _______  The four Paleozoic transgressive sequences are in order from oldest to youngest are Tippecanoe, Sauk, Kaskaskia, and Zuni. (F)

 

17.    _______  During the Sauk transgression, the Transcontinental Arch was a basin in which evaporite deposition occurred. (F)

 

18.    _______  The Transcontinental Arch and portions of the Canadian Shield were areas not covered by seas in the Sauk transgression.  (T)

 

19.    _______  During a transgressive sequence, sedimentary facies migrate toward the ocean. (F)

 

20.    _______  A normal sequence of sedimentary facies representing transgression would be from the bottom of a vertical sequence toward the top (a) sand, (b) mud, and (c) carbonate. (T)

 

21.    _______  Cambrian rocks exposed in the Grand Canyon region represent biostratigraphic zones. (F)

 

22.    _______  During a transgressive sequence, all nearshore facies sediments were deposited at the same time. (F)

 

23.    _______  The concept of time transgressive facies means that rocks of a particular facies type may not be the same age everywhere they are found.  (T)

 

24.    _______  After the Sauk Sea had regressed, the exposed surface of the North American continent was subjected to extensive glaciation. (F)

 

25.    _______  The boundary between the Tippecanoe and Sauk sequences is a vast unconformity with deep erosional relief. (T)

 

26.    _______  The basal unit of the Tippecanoe sequence is the Tippecanoe Sandstone. (F)

 

27.    _______  The basal unit of the Tippecanoe sequence is the St. Peter Sandstone. (T)

 

28.    _______  In the Tippecanoe Sequence, widespread carbonate deposition was related to the Taconic orogeny. (F)

 

29.    _______  The formation of dolostones is a result of calcium substituting for magnesium in the mineral calcite. (F)

 

30.    _______  Thick sections of evaporite deposits that were formed in basins surrounded by large reef complexes are common in the Tippecanoe sequence. (T)

 

31.    _______  The Taconic orogeny was the last of the major mountain building events in the Appalachians. (F)

 

32.    _______  A clastic wedge is a wedge shaped block of sedimentary rocks bounded by faults that intersect at an acute angle. (F)

 

33.    _______  The earliest organic reefs are known from the Ordovician Period. (F)

 

34._______  Clastic wedge deposits are thickest on the carbonate platform and thinnest near the highlands where they pinch out. (F)

 

35. _______ The mirror image of the Taconic orogeny in Europe is the Acadian orogeny in North America. (F)

 

36. _______  A shield consists of an exposed portion of Cambrian sedimentary and igneous rocks. (F)

 

37._______  The regressive phase of a sequence is marked by an unconformity. (T)

 

38._______  Within an evaporating basin, the first mineral to generally precipitate is calcium carbonate. (T)

 

39._______ In the Early Paleozoic, the Iapetus Ocean separated Lauentia from Baltica. (T)

 

40. _______The Paleozoic history of most continents involves very little tectonic activity, but a series of transgressions and regressions because of glaciation episodes. (T)