Practice Questions for Chapter 23
Geology 1200
Use these questions to test your knowledge of Chapter 23.
Multiple-Choice Questions
1) All of the following Mesozoic tectonic events occurred in western North America EXCEPT:
a) mountain building
b) breakup of Pangaea…
c) continental collisions.
d) accretion of terranes.
2)
The longest period of the Mesozoic Era was:
(a) they were all of equal length.
(b) the Triassic Period.
(c) the Jurassic Period.
(d) the Cretaceous Period..
3) Which of the following is NOT true concerning the periods of the Mesozoic?
(a) They all measure equal intervals of time..
(b) They were each defined from a different country.
(c) They all contain marine fossils where they were defined.
(d) The oldest interval was defined last.
4) The one Mesozoic period that was NOT defined in Europe was:
(a) the Cretaceous Period.
(b) the Jurassic Period
(c) the Triassic Period.
(d) all three periods were defined in Europe..
5) The Earth’s continents attained their familiar form by the beginning of the Cenozoic with the:
a) fragmentation of Pangaea…
b) accretion of Eurasia.
c) fragmentation of Eurasia.
d) accretion of Pangaea.
6) At the beginning of the Mesozoic, Pangaea:
a) stretched from pole to pole.
b) equally straddled the equator with both Northern and Southern hemispheres.
c) was surrounded by a worldwide ocean.
d) all of the above..
7) All of the following “breakup of Pangaea” events occurred in the Mesozoic EXCEPT:
a) South America separated from Africa.
b) North America separated from South America.
c) Australia separated from Antarctica…
d) North America separated from Africa.
8) The first stage in the breakup of Pangaea occurred when:
a) South America separated from Africa.
b) North America separated from South America.
c) Australia separated from Antarctica.
d) North America separated from Africa…
9)
All of the following tectonic events helped to form the Gulf of Mexico EXCEPT:
(a) rifting of North America from Africa.
(b) rifting of North America from South America.
(c) rifting of South America from Africa…
(d) flooding of the rift zone between North America and South America.
10) In the Late Jurassic, a three-way rift between Africa and South America produced an
aulacogen now occupied by the:
(a) Nile River.
(b) Amazon River.
(c) Niger River..
(d) Congo River.
11) The final stage in the breakup of Pangaea occurred when:
a) South America separated from Africa.
b) India separated from the rest of Gondwana.
c) North America separated from South America.
d) Australia separated from Antarctica…
12) In the Mesozoic, the continent of Pangaea was ice-free because:
a) warm equatorial waters from the Panthalassa Ocean reached both poles.
b) the Gondwana landmass drifted north into warmer climates.
c) the warming effects of the monsoon pattern, as indicated by paleosols.
d) a greenhouse atmosphere
e) All of the above..
13) Which of the following statements concerning Pangaean sediments is NOT true?
a) Mesozoic plant fossils indicate subtropical conditions in high latitude locations.
b) Ocean temperatures can be estimated by analysis of the shells of marine organisms.
c) Evaporite and eolian deposits indicate arid and semi-arid conditions for the Pangaean
interior.
d) Triassic coal deposits in Australia and Antarctica show strongly seasonal temperatures..
14) Which of the following statements concerning the Mesozoic climate of Pangaea is NOT true?
a) Glaciation briefly occurred in southern Gondwana..
b) Monsoon patterns were well developed in south Pangaea during Triassic and Jurassic
time.
c) Aridity in the interior of Pangaea occurred because of its isolation from ocean waters.
d) Red paleosols indicate wet and dry seasons for parts of Pangaea.
15) Laboratory measurements of carbonates reveal large concentrations of carbon dioxide present
in the Mesozoic atmosphere. This suggests:
a) a greenhouse climate.
b) an icehouse climate.
c) windy weather.
16) All of the following are sources for excessive Mesozoic carbon dioxide EXCEPT:
a) chemical weathering of the Appalachian Mountains (uses up CO2)..
b) rapid Cretaceous sea-floor spreading (volcanoes provide new CO2).
c) magmatic arcs of western North America (volcanoes provide new CO2).
d) volcanism associated with the breakup of Pangaea (volcanoes provide new CO2).
17) Which structure was not a product of the Mesozoic tectonic activity of eastern North
America?
a) Narrow sea. (rifting)
b) Passive margin. (drifting)
c) Island arc.. (these are associated with subduction zones)
d) Rift basins. (rifting)
18) Middle Triassic crustal extension produced what structural feature along the Atlantic margin?
a) Thrust faults. (convergent)
b) Normal faults.. (divergent)
c) Reverse faults. (convergent)
d) Complex folds. (convergent)
19) Which statement about Late Triassic and Early Jurassic sediments in eastern North America
is NOT true?
a) Sediments of the Newark Supergroup were briefly interrupted by volcanic activity.
b) Sediments of the Newark Supergroup filled Mesozoic rift basins.
c) Sediments of the Newark Supergroup represent alluvial deposits.
d) Sediments of the Newark Supergroup include a brief marine transgression..
20) Which type of volcanic activity was NOT present in the Early Jurassic of eastern North
America?
a) Island Arc volcanics..
b) Extensive rift valley basalts.
c) Emplacement of dikes
d) Emplacement of sills
21) The Atlantic margin of eastern North America contains:
a) rift basins.
b) continental shelf rocks.
c) wedges of sedimentary rocks that thicken seaward.
d) All of the above..
22) Which Mesozoic depositional event was NOT responsible for Gulf Coast petroleum deposits?
a) Deposition of Triassic redbed sediments..
b) Deposition of Early Jurassic evaporites.
c) Deposition of Late Jurassic and Early Cretaceous sediments over the evaporites.
d) Formation of Middle Cretaceous reefs
23) The source of organic matter for Gulf Coast petroleum deposits was:
a) deposition of Triassic redbed sediments.
b) deposition of Early Jurassic evaporites.
c) deposition of Late Jurassic and Early Cretaceous sediments over the evaporites..
d) formation of Middle Cretaceous carbonate reefs
24) Formation of the Gulf Coast petroleum deposits can be attributed to:
a) deposition of Triassic redbed sediments.
b) deposition of Early Jurassic sandstones
c) deformation of Late Jurassic and Early Cretaceous sediments by squeezed-up evaporites..
d) formation of Middle Cretaceous rudist reefs
25) Which Milankovitch cycle had the greatest period length?
(a) Earth’s axial wobbling.
(b) Earth’s orbital eccentricity..
(c) Earth’s axial tilt.
26) After a detailed structural and stratigraphic study of the western margin of North America, it
was realized that many problems in correlation were brought on by the presence of numerous:
(a) thrust faults.
(b) displaced terranes.
(c) rift basins.
(d) magmatic arcs.
27) The geologic history of displaced terranes is further complicated by:
(a) younger intrusion of older terranes.
(b) multiple episodes of folding and faulting.
(c) later movement along transform faults.
(d) All of the above..
28) After the Late Triassic, subduction of the Farallon plate beneath North America formed a
coastal:
(a) passive margin.
(b) rift zone.
(c) magmatic arc..
(d) mountain belt.
29) All of the following orogenies represent episodes of the Cordilleran Orogeny EXCEPT:
(a) the Nevadan Orogeny.
(b) the Sonoma Orogeny..
(c) the Sevier Orogeny.
(d) the Laramide Orogeny.
30) The Late Triassic to Late Jurassic Nevadan Orogeny is characterized by:
(a) uplift of basement rocks.
(b) thin-skinned tectonics.
(c) westward-dipping subduction.
(d) massive crustal intrusions (batholiths)..
31) The Cretaceous Sevier Orogeny is characterized by:
(a) uplift of basement rocks.
(b) thin-skinned tectonics..
(c) westward-dipping subduction.
(d) massive crustal intrusions.
35) The cause of compression during the Sevier Orogeny may be the docking of:
(e) Wragellia..
(f) Sonomia.
(g) Klamathia.
(h) none of the above.
32) All of the following represent geologic structures formed by the Laramide Orogeny
EXCEPT:
(a) deep basins.
(b) broad uplifts.
(c) steep-sided folds.
(d) massive batholiths..
33) The Late Cretaceous to Early Tertiary Laramide Orogeny was characterized by:
(a) near vertical uplift of blocks of basement rocks..
(b) thin-skinned tectonics.
(c) westward-dipping subduction.
(d) massive crustal intrusions.
34) Mesozoic tectonic activity in western North America included all of the following EXCEPT:
(a) volcanism.
(b) block uplifts.
(c) arc magmatism.
(d) rifting..
35) All of the following events occurred during the Mesozoic in western North America
EXCEPT
(a) erosion of orogens.
(b) sedimentation in foreland basins.
(c) thin-skinned tectonics.
(d) sedimentation in rift basins..
36) All of the following environments represent Mesozoic sedimentation in western North
America EXCEPT:
(a) alluvial plains.
(b) cyclic lake sequences..
(c) shallow cratonic seas.
(d) coastal dunes.
37) The cause of Late Cretaceous marine transgression involves all of the factors below
EXCEPT:
(a) rapid rates of sea-floor spreading.
(b) glacial melting..
(c) crustal subsidence.
38) All of the following marine sediments were deposited in western North America during the
Late Cretaceous EXCEPT:
(a) marginal marine clastics.
(b) chalk deposits.
(c) evaporites..
(d) dark shales.
39) All of the following tectonic regions in the Mesozoic western margin of North America are
present in California EXCEPT:
(a) the foreland basin..
(b) the forearc basin.
(c) the accretionary wedge.
(d) the magmatic arc.
40) Sediments of the Great Valley Group were deposited:
(a) in the foreland basin.
(b) in the forearc basin..
(c) as the accretionary wedge.
(d) in the magmatic arc.
41) Sediments of the Franciscan Group were deposited :
(a) in the foreland basin.
(b) in the forearc basin.
(c) as the accretionary wedge..
(d) in the magmatic arc.
E. Short Answer
1. Why is correlation of sedimentary rocks in western North America so difficult?