GEOL 105 Geology of Colorado CMU

In the Colorado National Monument, a major unconformity exists between the Precambrian rocks (1.4 billion years old) and the Triassic Chinle Formation (200 million years old). The hiatus represented by this gap is:

1200 million years

The oldest rocks in Colorado are approximately... old.

2.7 billion years

The Earth and the Solar System are about... old.

4.6 billion years

Based on the atomic number, there are... naturally occurring chemical elements on the Periodic Chart.

92

Which of the following is not a Physiographic Province in Colorado?

Cascade Mountains

Which of the following academic disciplines are major components of Geology?

Chemistry, Physics, and Biology

Grand Junction is located in the... Physiographic Province.

Colorado Plateau

The last time the area now known as Colorado was flooded by ocean water.

Cretaceous Period (Phase 4)

Numerous paleogeographic maps were shown during Prof. Cole's lectures. The geologist-artist who constructed these maps is...

Dr. Ron Blakey, recently retired from Northern Arizona University

Geologic Eras have longer time durations (more years in them) than Geologic Eons.

False

Mineraloids have a well defined crystalline structure.

False

The Pliocene is a geologic period.

False

The author of your textbook, Dr. Vince Matthews, is the former State Geologist of Utah.

False

We are currently living in the Mesozoic Era.

False

The scientific study of time as it applies the the Earth is called...

Geochronology

Denver is located on the western edge of the... Physiographic Province.

Great Plains

Which statement about James Hutton is true?

He is considered the "Father of Modern Geology".

The... is the driving force behind the formation of sediment at the surface of the Earth.

Hydrologic Cycle

Which of the following statements pertains to the concept of Superposition?

In a stack of undeformed sedimentary rocks, the oldest layer will be at the bottom.

Which of the following components of the Earth System is the most massive (greatest volume and weight)?

Lithosphere

Regarding quantitive (numerical) age dates for Precambrian igneous rocks in Colorado, which of the following statements is correct?

Most dates cluster around 250, 130, and 75 million years ago.

Regarding the Scientific Method, which of the following sequences is correct?

None

The plate-tectonic formation of the supercontinent called... was the trigger for creation of the Ancestral Rocky Mountains.

Pangea

Which of the following is a period in the Paleozoic Era?

Pennsylvanian

The youngest Geologic Eon.

Phanerozoic

The Precambrian includes the following time units.

Phanerozoic and Mesozoic

When did glaciation significantly impact Colorado?

Phase 6

Argon-40 is the radioactive decay product (daughter) of...

Potassium-40

You are driving on Interstate 70 over the Front Range near the Eisenhower Tunnel and your car sputters to a stop. As you wait for help to arrive, you start looking at the rocks in a nearby road cut. Which of the following will you observe?

Precambrian metamorphic and igneous rocks

The giant Phase 6 "crack" (divergent plate boundary) in Colorado is called the:

Rio Grande Rift

This orogeny took place in Utah, Arizona, and Nevada.

Sevier

Which statement summarizes the occurrence of Silurian sedimentary rocks?

Silurian sedimentary rocks are only found in diatremes of north-central Colorado.

The largest Physiographic Province in Colorado is:

Southern Rock Mountain

Which of the following statements is true?

The Miocene is a Geologic Epoch.

This simple statement explains what "Uniformitarianism" is.

The present is the key to the past.

Which of the following statements best summarizes Colorado's history during Phase 2 (Cambrian-Mississippian Periods)?

The seas came in and the seas went out

Which statement is false?

There are 3 types of strain (deformation): elastic, plastic, and spastic.

Which of the following statements describes the velocity at which tectonic plates move?

They move at about the same rate that your fingernails grow (inches per year).

Which of the following is a period in the Mesozoic Era?

Triassic

Geologic Periods have longer time durations (more years in them) than Geologic Epochs.

True

Silicate minerals that contain iron, such as biotite, are usually dark gray to black.

True

The boundary between the Mesozoic and the Cenozoic Eras is 65.5 million years ago.

True

The most common rock-forming mineral in the Earth's crust is quartz.

True

Which of the following is required for contact metamorphism to happen?

a magma body cooling at depth

If sedimentary rocks are deformed into a "Sag"-shaped fold (cross-sectional view), the structure is called:

a syncline

If sedimentary rocks are deformed into an "Arch"-shaped fold (cross-sectional view), the structure is called:

an anticline

Igneous rock type (magma type) that is created by partial melting of oceanic crust in a subduction zone.

andesite

Which of the following is an intermediate volcanic rock?

andesite

This partially molten layer of igneous rock underlies the lithosphere.

asthenosphere

The assigned video was produced by geologists and graphic artists...

at the University of Colorado, Boulder

The largest igneous pluton is called a...

batholith

Diamond is composed of this chemical element:

carbon

From the surface of the Earth downward to the center, the Earth's internal zones are:

crust, mantle, outer core, inner core

Extrusive igneous rocks have large crystals and intrusive igneous rocks have small crystals.

false

Which of the following is not a basic type of heat transfer?

gravity

The energy that drives the "tectonic engine" (plate movement) comes from:

heat, which comes from radioactive decay of uranium, thorium, and potassium, plus heat left over from the Earth's formation.

This oxide mineral has a rusty color.

hematite

Rhyolite belongs to this rock group.

igneous

The Earth's core is thought to be composed of mainly...

iron and nickel

If we could use a time machine to visit Grand Junction area during late Phase 3 (Jurassic) when the Wingate Sandstone was being deposited, we would see:

large migrating sand dunes

Igneous rocks form from crystallization of...

magma

During contact metamorphism, a limestone becomes a...

marble

Gneiss belongs to this rock group.

metamorphic

Heat, pressure, and chemical alteration of a preexisting rock in the subsurface are required to form this group of rocks.

metamorphic

By definition, the rocks below a nonconformity consist of:

metamorphic and/or igneous rocks

A spectacular fold called a... can be seen in the sedimentary rocks along the front of the Colorado National Monument.

monocline

Which of the following is a mica mineral?

muscovite

Which of the following igneous rocks has a glassy texture?

obsidian

The term used to define a period of mountain building in the geologic past.

orogeny

Which of the following is an ultramafic igneous rock?

peridotite

Which of the following is foliated metamorphic rock?

phyllite

An igneous rock that has both large and small crystals is said to have a... texture.

porphyritic

Contact metamorphism of sandstone will produce a...

quartzite

Which of the following is a chemical sedimentary rock?

rock salt (halite)

Chemical and physical weathering at the Earth's surface are required to form this rock group.

sedimentary

Limestone and sandstone belong to this rock group.

sedimentary

Which of the following is a biochemical sedimentary rock composed of sea shells?

skeletal limestone

As heat and pressure are applied to a shale, which of the following is the correct sequence of foliated metamorphic rocks that will form as time passes?

slate (first), phyllite, schist, gneiss (last)

New oceanic crust is created here.

spreading ridges at divergent plate boundaries

These two sedimentary rock units are Precambrian in age.

the Uinta Mountain and Uncompahgre Groups

A normal fault is defined by:

the foot-wall block moving up with respect to the hanging-wall block.

The time required for one-half of the radioactive parent atoms to decay to their stable daughter atoms is called:

the half life

A reverse fault is defined by:

the hanging-wall block moving up with respect to the foot-wall block.

An arkosic sandstone has more than 25 percent feldspar grains.

true

Igneous dikes cut across the layering found in sedimentary rocks.

true

Toadstool (mushroom) shaped intrusive igneous bodies (plutons) are called laccoliths.

true

Volcanic cinders, ash, and bombs are called "pyroclastics".

true

To create a sedimentary rock, which of the following sequences is correct?

weathering (first), transportation, deposition, and lithification (last)

When an igneous rock is dated by the uranium-lead or other radiometric methods, the number (date) that is obtained indicates:

when the magma cooled and solidified into rock.

If an igneous dike cross-cuts a sandstone bed, the dike is... the sandstone.

younger than