exam 2 geology 101
What can occur in association with a thrust fault?
All of these choices are correct.
Which location on this diagram would most likely record contact metamorphism in shallow levels of the crust?
1
Which of the numbers on this figure indicates low pressure/high temperature metamorphic conditions?
1... between schist and gneiss
Which of the numbers on this figure indicates typical continental conditions (regional metamorphism)?
2
Shale is metamorphosed into three rock types: (1) a banded gneissic rock; (2) a rock with small mica crystals with a shiny aspect; (3) a very shiny rock with large mica crystals; and (4) a dull slate with cleavage. Which of the following lists these rocks in order of increasing metamorphic grade?
4, 2, 3, 1
Identify the factor(s) that strongly influence the size, shape, and/or sorting of sedimentary clasts.
All of these choices are correct.
What chemical processes can occur during metamorphism and deformation?
All of these choices are correct.
Which of the following processes produce sedimentary clasts?
All of these choices are correct.
What is the typical relationship of cleavage to folds?
Cleavage is usually parallel to the axial surfaces of folds.
Which of the following is a good interpretation of the environmental significance of an attribute of a sedimentary rock?
Graded beds indicate that the strength of the current decreased through time.
Which of the following is a correct statement about resources in sedimentary rocks?
Groundwater mostly resides in the pore spaces between grains and in fractures.
Which of the following is a valid statement about how rocks respond to stress?
If a rock has strained, then it has changed its size or shape.
The effect of transportation on a pebble's particle size is best summarized by which statement?
Its size decreases.
What type of structure is shown in this figure?
Joint
Which of the following is characteristic of a regression?
Sand dunes and river sediments can be deposited over marine deposits.
What typically happens to the size, shape, and sorting of clasts as they are transported from steep mountains toward more gentle settings?
The clasts become more rounded.
How would the force and stress on the wooden pillar in this figure change if the stone weight were the same size but the wooden pillar were narrower?
The force would remain the same, but the amount of stress would increase.
Which of the following interpretations is consistent with the character and sequence of rocks in this figure?
The lower part of the section is consistent with deposition of marine layers over sand dunes.
Which of the following is a common characteristic of carbonate rocks?
They commonly have a dissolved appearance.
Which of the following statements is NOT true about clastic sedimentary rocks?
To be called a sandstone, quartz must make up more than 95 percent of the grains.
Which of the following is NOT something we can learn by studying geologic structures and metamorphic rocks?
We can learn information about all these things.
Which of the following environments would likely have clasts smaller than sand?
a weak current
If a rock is poorly sorted, this means the rock contains
a wide range in the size of clasts.
What type of structure is shown in this figure?
anticline
What is the typical setting for fold and thrust belts?
associated with convergent plate boundaries
This sandstone includes shells of marine creatures that live in shallow water. What is the most likely environment in which it formed?
beach next to a sea
Why could the geologic setting in this figure cause metamorphism?
because it forces some rocks deeper as they are overridden by rocks above the fault
The rounded clasts in this sedimentary deposit were likely transported
by a river.
A sandstone containing mostly sand but mixed with rounded pebbles and pieces of shells indicates deposition
by waves at the beach.
What type of stress formed the structure shown in this figure?
compression
What are the three main types of stress?
compression, tension, and shear
These sandstone beds are interlayered with dark marine shales. What is the most likely environment in which the sandstone formed?
deep-water turbidity currents
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.
What types of features are shown in this photograph of unmetamorphosed sedimentary rocks?
erosion of strong and weak layers
Fractures along which the rock has slipped relative to the other side are called
faults.
How did the joints in this photograph form?
from cooling
What type of structure is shown in this figure? in a U or V shape
horizontal syncline
A nonfoliated metamorphic rock not created by pressure or differential stress, but by being baked by an igneous intrusion, is a
hornfels.
In what site on this figure would you expect low pressure/high temperature metamorphism?
in magma chamber
Which of the following sites would contain the finest grained sedimentary deposits?
lake at E
Which of the following sites would have the slowest moving or least energetic current?
lake at E
What type of rock forms through solid-state alteration of a previously existing rock, by heating, pressure, and/or fluid chemistry?
metamorphic
What type of fault is shown in this figure?
normal fault
Sedimentary rocks are comprised of material that comes primarily from
other locations
Which of the following processes is NOT considered physical weathering?
oxidation
The two main processes by which sediment is produced are
physical and chemical weathering.
Peat forms from the accumulation of
plant material.
what type of structure is shown in this figure below
plunging syncline
Which of the following is NOT a common type of cement in sedimentary rocks?
pyroxene
The most likely cause of graded bedding found in sedimentary rocks is
reduction in water current velocity.
Sedimentary facies shift toward the sea as the sea moves out during a
regression
What type of fault is forming here?
reverse fault
The rock shown here, with sediment just visible to the naked eye, is a
sandstone.
Most of the exposed surface of the Earth is covered with
sediment and sedimentary rocks.
Clastic sedimentary rocks are classified primarily on the basis of
sediment size.
The special geologic terms used to represent the direction of a horizontal line on an inclined surface (asin a fault) and the angle of that surface to the horizontal are
strike and dip.
A fold in which rocks fold down in the shape of a U is a(n)
syncline
If the view is looking north, which of the following correctly indicates which rocks are higher in metamorphic grade in the following image?
the banded rocks to the east
Which of the rock layers in this figure was most likely deposited by sand dunes on land?
the lowest red sandstone
Sorting describes
the size range of clasts in sediment.
Which of the following features is older than fault 1?
tilted layers
The advance of the sea across a region is known as a
transgression.
Downslope marine flows composed of mixed masses of sand, mud, and water are called
turbidity currents.
