geology 6, 7, 8

Which of the numbered features is a lava flow?

1

Which of the numbers on this figure indicates typical continental conditions (regional metamorphism)?

2

Flood basalts influence life on Earth because:

Eruptions can release large amounts of gas that cool the atmosphere Large volumes of flood basalts are erupted during a short time Eruptions can release large amounts of gas that warm the atmosphere

The effect of transportation on a pebble's particle size is best summarized by which statement?

Its size decreases

This relatively small volcanic feature consists of solidified lava and some volcanic ash. What kind of volcano is it?

NOT composite volcano scoria cone caldera shield volcano

What can you infer from this contact between an overlying conglomerate and underlying sandstone?

There was an abrupt event, such as a flood.

What feature is displayed as the two prominent, vertical lines cutting across the metamorphic rock in the image?

Two thin shear zones

In what site on this figure would you expect high pressure/low temperature metamorphism?

a and b

What type of tectonic event formed the main structures in the Valley and Ridge Province of the Appalachian Mountains?

a continental collision

What type of eruption formed this flow-banded rhyolite?

a pyroclastic column

What type of volcanic eruption is shown in this photograph?

a pyroclastic column

What type of eruption formed this unit composed of volcanic blocks and volcanic ash?

a pyroclastic eruption

Which of the following does NOT help define layers in some sedimentary rocks?

a sharp contact between two rock types a change in mineral composition a change in grain size a change in color

If a rock is poorly sorted, this means the rock contains:

a wide range in the size of clasts

This photograph shows chalk. How is it formed?

accumulation of microscopic organisms composed of calcium carbonate

This photograph shows chert. How does it form?

accumulation of silica-rich organisms or mixing of seawater and groundwater

Which of the following does NOT help define lineation in some metamorphic rocks?

alternating layers of dark- and light-colored rock types

What type of volcanic eruption is probably shown in this photograph?

basaltic

Sediments with a large amount of sand are most likely at:

braided river at C and delta at D

Which of the following is most likely to occur at shallow crustal levels?

brittle deformation

Huge circular depressions from which volcanoes erupt are called

calderas

This relatively large, symmetrical volcano contains interlayered lava flow, pyroclastic deposits, and volcanic mudflows. What kind of volcano is it?

composite volcano

Which of the following sites would most likely have turbidity currents?

deep seafloor at D

These sandstone beds are interlayered with dark marine shales. What is the most likely environment in which the sandstone formed?

deep-water turbidity current

Which of the following sites would have sand and silt deposited by slowing of the current?

delta at d

A very well sorted sandstone with large-scale cross-bedding indicates the sand was likely:

deposited by the wind in dunes

When a rock is subjected to tectonic forces and experiences stress that is not the same in all directions, it is under:

differential stress

Which of the following types of volcanic eruption have occurred on Mount St. Helens since it began erupting in 1980?

eruption column volcanic dome pyroclastic flow

Fractures along which the rock has slipped relative to the other side are called:

faults

What type of metamorphic feature is shown in this photograph?

foliation in banded gneiss

When basaltic lava reach the ocean they:

form pillow basalts

Under what conditions was this rock likely deformed?

hot and deep conditions

Lithifies can be defined as:

loose sediment hardens into sedimentary rock

Long, thin lava flows are typically produced by:

low-viscosity lavas

A fold that has only one dipping segment is a(n):

monocline

What tectonic setting is interpreted to be the cause of volcanism at Yellowstone?

movement of North America over a mantle plume

What type of basaltic feature is shown in this photograph?

pahoehoe lava flow

The two main processes by which sediment is produced are:

physical and chemical weathering

What type of material likely composes this volcano?

pyroclastic flows felsic to intermediate lava flows volcanic mudflows and landslides

What type of fault is shown in this figure?

reverse fault

This volcano is relatively small and composed of volcanic cinders. What kind of volcano is it?

scoria cone

Most of the exposed surface of the Earth is covered with:

sediment and sedimentary rocks

Which of the following matches a sedimentary rock with a possible metamorphic equivalent?

shale-slate

What type of stress formed the structure shown in this figure?

shear

This volcano is broad and low, and is composed of basaltic lava flows. What kind of volcano is it?

shield

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?

the area was experiencing a regression

Imbricated clasts in this river means that:

the current flowed from right to left

Which of the following processes is NOT considered to be chemical weathering?

thermal expansion

Which of the following environments would most likely have sediment formed by evaporation of seawater?

tidal flat at E

What are the rounded hills inside the Valles Caldera?

volcanic domes