GEOL 100 ch 6-8
Which of the numbered features is a lava flow?
a. 1
What type of tectonic event formed the main structures in the Valley and Ridge Province of the Appalachian Mountains?
a. a continental collision
What type of eruption formed this flow-banded rhyolite?
a. a viscous lava flow
A fold that has only one dipping segment is a(n):
a. monocline
What type of basaltic feature is shown in this photograph?
a. pahoehoe lava flow
This volcano is relatively small and composed of volcanic cinders. What kind of volcano is it?
a. scoria cone
What are the rounded hills inside the Valles Caldera?
a. volcanic domes
Which of the numbers on this figure indicates typical continental conditions (regional metamorphism)?
b. 2
This photograph shows chalk. How is it formed?
b. accumulation of microscopic organisms composed of calcium carbonate
When a rock is subjected to tectonic forces and experiences stress that is not the same in all directions, it is under:
b. differential stress
What type of metamorphic feature is shown in this photograph?
b. foliation in banded gneiss
Long, thin lava flows are typically produced by:
b. low-viscosity lavas
What tectonic setting is interpreted to be the cause of volcanism at Yellowstone?
b. movement of North America over a mantle plume
Which of the following matches a sedimentary rock with a possible metamorphic equivalent?
b. shale-slate
Imbricated clasts in this river means that:
b. the current flowed from right to left
In what site on this figure would you expect high pressure/low temperature metamorphism?
c. A and B
What can you infer from this contact between an overlying conglomerate and underlying sandstone?
c. There was an abrupt event, such as a flood
What type of eruption formed this unit composed of volcanic blocks and volcanic ash?
c. a pyroclastic eruption
Which of the following does NOT help define lineation in some metamorphic rocks?
c. alternating layers of dark- and light-colored rock types
This relatively large, symmetrical volcano contains interlayered lava flow, pyroclastic deposits, and volcanic mudflows. What kind of volcano is it?
c. composite volcano
A very well sorted sandstone with large-scale cross-bedding indicates the sand was likely:
c. deposited by the wind in dunes
Fractures along which the rock has slipped relative to the other side are called:
c. faults
Under what conditions was this rock likely deformed?
c. hot and deep conditions
What type of fault is shown in this figure?
c. reverse fault
What type of stress formed the structure shown in this figure?
c. shear
In this section, a lower gray rock is successively overlain as follows: limestone is overlain by mudstone, which is overlain by beach sandstone. What is the best interpretation of what was going on?
c. the area was experiencing a regression
What feature is displayed as the two prominent, vertical lines cutting across the metamorphic rock in the image?
d. Two thin shear zones
This photograph shows chert. How does it form?
d. accumulation of silica-rich organisms or mixing of seawater and groundwater
Flood basalts influence life on Earth because:
d. all of these
What type of material likely composes this volcano?
d. all of these
Which of the following types of volcanic eruption have occurred on Mount St. Helens since it began erupting in 1980? a. eruption column b. volcanic dome c. pyroclastic flow d. all of these
d. all of these
These sandstone beds are interlayered with dark marine shales. What is the most likely environment in which the sandstone formed?
d. deep-water turbidity currents
What type of metamorphic feature is shown in this photograph?
d. foliation in banded gneiss
When basaltic lava reach the ocean they:
d. form pillow basalts
Which of the following does NOT help define layers in some sedimentary rocks?
e. all of these are ways that can define layers in sedimentary rocks
Which of the following is most likely to occur at shallow crustal levels?
e. brittle deformation