Download Historical Geology, Chapter 1 Learning Objectives and Study

Historical Geology, Chapter 1
Learning Objectives and Study Questions
1. Explain how our current understanding of actualism accounts for the fact that some types of
rocks, such as komatiites and banded iron formations, formed on Earth during the past but
are no longer being formed today.
2. Use the relative dating principles discussed in class to order the sequence of events shown
on a geologic map or in a cross-section, and justify your decisions.
3. Draw a diagram of the geologic time scale and label the names and beginning and ending
dates of the major subdivisions discussed in class.
4. Draw a neatly labeled cross-section that shows the structure of Earth’s lithosphere and
includes the names, rock types, and thicknesses of its major parts.
5. Distinguish between the three types of plate boundaries based on the relative motions of
the lithospheric plates across them and the general patterns of seismicity and volcanism
along them.
6. Recognize an unconformity on a simple geologic map or cross-section, and correctly
interpret its significance for the geologic history of the region shown.
1. The principle that ancient geologic features can be interpreted in terms of modern
processes because physical laws remain constant is called _____.
A. actualism
B. catastrophism
C. neptunism
D. plutonism
E. uniformitarianism
2. The view, which persisted into the early 1800s, that Earth and all its life formed only 6,000
years ago required that geologic changes occurred very rapidly and on scales we do not see
today. This view is embodied in the principle of _____.
A. actualism
B. catastrophism
C. neptunism
D. plutonism
E. uniformitarianism
3. To locate the oldest strata in the Grand Canyon you would look at the bottom of the gorge
according to the principle of _____.
A. original horizontality
B. lateral continuity
C. inclusions
D. crosscutting
E. superposition
4. In the accompanying cross-section we
can infer that the dike D is _____ fault
F on the basis of the principle of
cross-cutting relationships.
A. older than
B. the same age as
C. younger than
D. of indeterminate age relative to
E. way cooler than
5. The widespread development of hard parts in animals marked the beginning of the _____
about 540 Ma (million years ago).
A. Archean Eon
B. Hadean Eon
C. Paleozoic Era
D. Proterozoic Eon
E. Mesozoic Era
6. The beginning of the Cenozoic Era about 65 Ma was marked by:
A. formation of Earth’s oldest rocks
B. a mass extinction
C. widespread development of hard parts in animals
D. the development of large continents
E. formation of an oxygen-rich atmosphere
7. Compared to the underlying asthenosphere, Earth’s lithosphere (“plates”) are _____ and
_____.
A. cool, weak
B. warm, weak
C. cool, rigid
D. warm, rigid
E. dense, weak
8. Typically, continental lithosphere extends to a depth of about _____ kilometers.
A. 7
B. 45
C. 100
D. 150
E. 350
9. Continental margins marked by: deep ocean trenches, dipping zones of shallow to deep
earthquakes, and chains of volcanoes on the continents are likely to be:
A. divergent boundaries
B. convergent boundaries
C. shear boundaries
D. inactive boundaries
E. hotspot tracks
10. Oceanic plate boundaries characterized by: relatively high elevations, shallow earthquakes,
extensional faulting, and eruptions of basalt lava are likely to be _____.
A. divergent boundaries
B. convergent boundaries
C. shear boundaries
D. inactive boundaries
E. hotspot tracks
11. The surface that separates
sedimentary beds S from the
underlying rock units is a/an _____.
A. fault
B. bed
C. fracture
D. unconformity
E. horizon