Ch. 5 Fall 2010 Note: not covered – fossils, names of rock units, correlation
Concepts: unconformities – disconformity, angular unconformity, nonconformity
sedimentary facies
marine transgression – regression – Walther’s law
Review Questions Pg. 99: 6, 7, 9, 10, 11, 12, 14 (answers at back of book)
Review terms: angular unconformity, conformable, disconformity, fossil (in
general), marine regression, marine transgression, nonconformity, principle of
fossil succession, principle of inclusions, relative geologic time scale,
sedimentary facies, unconformity, Walther’s law
Practice Questions:
1. An erosional surface that separates strata that are parallel with one another is called
a(n)
A. angular unconformity
B. disconformity
C. nonconformity
D. bedding plane
2. An erosional surface that separates tilted strata below from flat lying strata above is
called a(n)
A. angular unconformity
B. disconformity
C. nonconformity
D. bedding plane
3. An erosional surface that separates older metamorphic or igneous rocks from younger
overlying sedimentary rocks is called a(n)
A. angular unconformity
B. disconformity
C. nonconformity
D. bedding plane
4. What is the correct order of sedimentary facies, from shoreline toward open water?
A. shale, mud, and sand
B. limestone, sand and conglomerate
C. limestone, shale, and mud
D. sandstone, shale, and limestone
5. The term facies in sedimentary rocks refers to the
A. lateral changes resulting from deposition in different depositional environments
that had existed simultaneously
B. vertical variation resulting from deposition in the same environment separated
by significant time intervals
C. lateral variation resulting from deposition in the same environment separated by
significant time intervals.
D. laterally homogeneous strata deposited over a long time interval in the same
environment
6. Sedimentary facies are a result of
A. similar depositional processes operating in adjacent environments
B. similar depositional processes operating in geographically separate
environments
C. different depositional processes operating in geographically separate
environments
D. different depositional processes operating in adjacent environments
7. Which of the following is a cause of marine transgressions?
A. continental uplift
B. lowering of sea level with respect to a continent
C. rapid sea floor spreading
D. formation of large glaciers.
10. Of the following, which was not used by 19th century geologists for developing the
geologic column?
A. fossil succession
B. radiometric age dating
C. superposition
D. rock types and composition
12. Radiometric dating of detrital minerals (particals) in sedimentary rocks gives
A. the exact age of the sedimentary rock
B. an age older than the sedimentary rock
C. an age younger than the sedimentary rock
D. the age of lithification of the sedimentary rock
13. You date an igneous rock that cuts across a sedimentary layer. What can you
determine about the age of the sedimentary rock?
A. a minimum age
B. a maximum age
C. no age inference can be made at all
D. an exact age
E. an age range
14. In the field, a geologist notices igneous rock below parallel sedimentary layers. The
igneous rock has pieces of limestone from the first sedimentary layer contained
within it. What can be said about the age of the limestone?
A. The limestone was deposited simultaneous as the emplacement of the igneous
rock.
B. The limestone is older than the igneous rock
C. The limestone is younger than the igneous rock
D. The limestone can only be dated through its included fossils
15. Which is not true in the following diagram?
A. This represents a rise in sea level.
B. The sandstone at point A is younger than at point B.
C. The limestone at point C is the same age as the shale at point D.
D. The principle of superposition can be applied to these layers.
A
C
B
D
16. According to Walther’s Law, which of the following is true?
A. Figure A represents a marine regression and Figure B represents a marine
transgression
B. Figure A represents a marine transgression and Figure B represents a marine
regression
C. Both figure A and B represent marine transgressions
D. The horizontal lithology is required to determine what the layers mean.
Limestone
Sandstone
Shale
Shale
Sandstone
Limestone
Fig. A
Fig. B