The Michigan Basin of Silurian time is famous for its accumulation of great thicknesses of:

•  Black Shales
• Pure Limestones
• Evaporate Minerals
• Coal Deposits
• Gravel

Evaporate Minerals

Exam #3

Rocks shed from the Antler Orogeny eastward down into the tectonic trough toward present-day Montana were predominantely:

• Clastic sediments
• Micrite Limsetones
• Arkoses
• Flood basalts
• Oolitic limestones

Clastic Sediments

Exam #3

Fast, agile predatory Devonian fish with jaws(and many fins) are known as:

• Acanthadonians
• Ostracoderms
• Sharks
• Placoderms
• Spiny Rays

Acanthadonians

Exam #3

This carnivorous reptile with a fan-like, finned back, common in Permian time was an important ancestor of the dinosaurs.

• Ichthyosaurus
• Triceratops
• Dimetrodon
• Hadrosaurus
• Lystrosaurus

Dimetrodon

#3

 The Permian Delaware and Midland basins of Texas are famous for deposists of evaporite minerals and associated

• Uranium
• Coal
• Phosphate
• Oil
• Gravel

Oil

#3

The lower parts of the cyclotherms in the eastern U.S. are economically important because they contain significant deposits of ______ in Pennsylvanian rocks:

• Uranium
• Phosphate
• Arkose
• Marine Limestone
• Coal

Coal

#3

Permian reefs contained ma unusual organisms, but were noteworthy for the presence of :

• Large Trilobites
• Mud Mounds
• Sponges
• Crinoid Thickets
• Eurypterids

Sponges

#3

Small coral "patch reefs", some growing n the same site repeatedly to form tall pinnacle structures in the rock record, are dominant in this Period of geological time:

• Archean
• Mississippian
• Cambrian
• Proterozoic
• Silurian

Silurian

#3

Karst is a term applied to essentially "dissolved" landscapes from long-term weathering of exposed:

• Granites
• Shales
• Sandstones
• limestones
• Lava flows

Limestones

#3

Triassic basins developed in the present eastern U.S. during Triassic time are the result of tectonic:

• Uplift of the eastern part of N.A.
• Strike-slip faulting along a transform plate-boundary
• Extension from continental crust rifting
• Formation of an east-coast subduction zone
• Convergence as tectonic plates collided

Extension from continental crust rifting

#3

Pangaea first became completly assembles during this period of geological time

• Pennsylvanian
• Permian
• Triassic
• Jurassic
• Cretaceous

Permian

#3

These animals resemble a delicate starfish on a long stalk, and are responsible for stablizing sediment and contributing large amounts of debris so that reefs may become established:

• Brachiopods
• Chain corals
• Stromatoporoids
• Cephalopods
• Crinoids

Crinoids

#3

The Phosphoria formation of SE Idaho is thought to have been deposited by strong upwelling, nutrient-rich currents:

• In a river delta complex
• In a deep ocean basin setting
• In the shallow shelf near the beach
• In dense, stagnant mangrove swamps
• At the shelf edge where the continental slope begins

At the shelf edge where the continental slope begins

#3

The crinoids are the best index fossil representative of ______ time:

• Devonian
• Mississippian
• Pennsylvanian
• Permian
• Triassic

Mississippian

#3

True or False:

Extensive, long barrier reefs are common during Devonian time.

True

#3

True or False:

Cosmopolitanism is common in Permain floras and faunas because of mountain building during the assembly of Pangaea.

False

#3

True or False:

The Humboldt Orogeny resulted in a series of basins and block-faulted mountains in the western U.S. during Pennsylvanian time

True

#3

True or False:

Ocean currents on a global scale are more vigorous when a gentle climatic gradient (warm poles and equator) exists without a large temperature contrast.

False.

Contrasting temperatures at the poles cause vigorous ocean currents on a global scale.

#3

True or False:

The Ouachita Orogeny in Arkansas and Texas occurred during Pennsylvanian time.

True

#3

True or False:

Decreasing levels of atmospheric oxygen allow many organisms (such as insects) to attain gigantic proportions.

False.

High levels of atmospheric oxygen cause gigantism in insects.

#3

True or False:

The "petrified forest" in Arizona is of Permian age.

False

#3

True or False:

The Silurian sequence of rocks at Niagara Falls represents a regression.

False

#3

True or False:

Mississippian rocks in the western U.S. are characterized by layers of gray sandstone.

False.

#3

True or False:

During times of rapid sea level rise caused by ice cap build-up and retreat, sea level tends to rise faster than it drops.

True

#3

Triassic

#3

Panthalassa

#3

Definitions

Jawless, bottom-feeding Devonian fish with shelly armor.

Definitions

Arkose deposits of the Ancestral Rockies in Colorado.

Jefferson Formation

#3

Definitions

Shallow marine Mississippian limestones in Montana

Madison Groups

#3

Definitions

Huge Devonian fish the size of a school bus.

Dunkleosteus

#3

Definitions

Large coil-jawed Permian shark in SE Idaho rocks.

Helicoprion

#3

Definitions

Major transgressive event that caused the Mississippian onlap.

Kaskaskia

#3

Definitions

Triassic/Jurassic coastal sand dunes in desert SW U.S.

Navajo Sandstone

#3

Definitions

A rock composed entirely of fossil crinoid debris.

encrinite

#3 

Definitions

Colliding exotic terrane responsible for Antler Orogeny.

Klamath Terrane

#3

Definitions

Chocolate brown limestones in SW Montana originating from the Triassic.

Dinwoody Formation

#3

Definitions

Arkose deposits of the Ancestral Rockies in Colorado.

Fountain Formation

#3

Definitions

Plate-covered and armored Devonian fish with jaws.

Placoderms

#3

The Wood River Formation is composed of ______ clastic sediments that filled a small basin near Ketchum and Sun Valley, Idaho from both east and west directions.

• Devonian
• Mississippian
• Pennsylvanian
• Permian
• Triassic

Pennsylvanian

#3 bonus Q.

Eurypterids are most commonly found in the depositional environment:

• Brackish bays (mixed fresh and salt water)
• Shallow fresh water rivers and streams
• Deep ocean basins
• Desert sand dunes

Brackish Bays

#3 bonus Q.

This period of geologic time is notable for extreme temperature contrasts, with very cold polar areas and a tropical equator:

• Devonian
• Pennsylvanian
• Mississippian
• Cambrian

Pennsylvanian

#3 bonus Q.

Short Answer

What are the four phases of Devonian reef development. Name them in order from top to bottom.

Domination

Diversification

Colonization

Stablization(pioneer)

Multiple Choice

Graded beds of sediment deposited by waningg (slowing) water currents are characterized by:

• Layers deposited at an angle
• Fining-upward particle size in a depositional layer
• The presence of mudcracks
• The presence of ripple marks
• The Tracks and burrows of organisms

Fining-upward particle size in a depositional layer.

Sand-----> Silt

Multiple Choice

Sediments that have been bioturbated, resulting in distinct mottling, are the result of:

• Asteroid impacts
• Burrowing organisms
• Tsunamis in shallow seas
• Low-grade metamorphism
• Tectonic effects related to continental collision

Multiple Choice

A sheet-like igneous body which intrudes older rocks by following the existing layers of country rock is known as:

• Dike
• Pluton
• Sill
• Flow
• Batholith

Sill

Exam #2

Multiple Choice

The basic raw material required for cement production is:

• shale
• limestone
• granite
• sandstone
• basalt

Limestone

exam #2

Evidence of extensive "ice-age" glaciation is preserved in the rock record near the end of both _____ and Ordovician time.

• Silurian
• Cambrian
• Devonian
• Mississippian
• Proterozoic

Proterozoic

Exam #2

Multiple Choice

Organic reefs of Cambrian time were constructed primarly by these organisms:

• Stromatolites
• Corals and stromatoporoids
• Archeocyathids
• Oysters and clams
• Brachiopods and crinoids

Archeocyathids

Exam #2

Multiple Choice

The unique, soft=bodied organisms of the Middle Cambrian Burgess fauna lived in a(n) ____ and were deposited in a(n) adjacent:

• Shallow coral reef, shallow sandstone bed
• Algal reef, deep water black shale
• Sandstone bed, basalt flow
• Shallow continental shelf, sand dune deposit
• Alpine meadow, lake deposit

algal reef, deep water black shale

Exam #2

Multiple Choice

Rocks of the _____ Group/Formation within the Belt Supergroup are the only unit likely to indicate ocean water entering the basin and depositing abundant carbonate rocks:

• Ravalli
• Piegan (middle belt)
• Missoula
• Prichard
• Uinta

Piegan

Exam #2

Multiple Choice

Triolbites are considered an index fossil for this period of Paleozoic time:

• Permian
• Pennsylvanian
• Mississippian
• Cambrian

Cambrian

Exam #2

Multiple Choice

These shellfish superficially resemble clams, and are important fossils throughout Paleozoic time:

• stromatolites
• corals
• archeocyathids
• acritarchs
• brachiopods

brachiopods

exam #2

Multiple Choice

The unique Ediacaran fauna of soft-bodied organisms is of this age:

• Late Proterozoic
• Cambrian
• Silurian
• Ordovician
• Devonian

Late Proterozoic

exam #2

Multiple Choice

The Belt basin accumulated a tremendous thickness of sediment, but remained shallow over a long period of geologic time because of the effects of:

• tidal action
• orogenies
• subsidence
• isostacy
• subduction

isostacy

exam #2

Diaictites are very good indicators of sediment deposition related to:

• Rivers
• Deserts
• Swamps
• Glaciers
• High Mountains

Glaciers

Exam #2

Multiple Choice

The late Proterozoic Windermere Group rocks are characterized by:

• Fine-grained immature clastic sediments
• coral reef limestones
• deep water black shales
• algal reef limestones

fine-grained immature clastic sediments

Exam #2

Multiple Choice

Rocks of the Belt Supergroup consist mostly of:

• Intrusive rocks
• High temperature volcanics
• pillow lavas
• greenstone belts
• slightly metamorphosed sediments

slightly metamorphosed sediments

exam #2

Multiple Choice

This unusual large predatory creature of the Burgess Shale is about a meter long with a segmented body and a pair of grabbing tentacles:

• Hallucegenia
• Phacops
• Catenipora
• Halysites
• Anomalocaris

Anomalocaris

Exam #2

Multiple Choice

The Proto-Atlantic ocean, closing slowly during the early Paleozoic, is known as the:

• Tethys
• Iapetus
• Hercynian
• Panthalassa
• Pacific

Iapetus

Exam #2

Multiple Choice

"Black Smokers" are:

• Proterozoic lava flows
• Submarine hot springs
• Pre-cambrian dust storms
• Deep-water stromatolites
• Asteroid impact sites

submarine hot springs

exam #2

Multiple Choice

The ultimate cause of extinctions among shallow marine organisms during times of global sea-level lowering is generally:

• Overcrowding
• Abnormally high water temperatures
• Starvation
• Lack of Competition w/in same species
• Lack of genetic diversity

Overcrowding

Exam #2

Multiple Choice

The _____ is the fundamental unit of stratigraphy, and describes a distinct rock unit (layer) that is laterally extensive and of mappable thickness:

• Supergroup
• Formation
• member
• Bed

Formation

Exam #2

True or False

Coarse sediemnts of gravel size are very rare and unusual in the Belt Supergroup rocks.

True.

exam #2

True or False

Cosmopolitan organisms are present over a large geographic area. 

True

exam #2

True or False

The Depositional basin for the Belt rocks most likely orignated through crustal faulting related to a continental rifting event. 

True

exam #2

True or False

Paleozoic sediments are much thicker than Precambrian units in both Idaho and Western Montana. 

False

Exam #2

True or False

Windermere sedimentary rocks were deposited as a sediment wedge into the open ocean to the west.

True

exam #2

True or False

Cephalopods (large squid in long shell) were major late Proterozoan predators.

False

exam #2

True or False

Major mountain-building is absent in western North America during the early Paleozoic. 

True.

exam #2

True or False

Regressive sequences generally show evidence of erosion that removes the upper part of the stack (sequence) after deposition. 

True

exam #2

True or False

North America was located in a equatorial position during the Cambrian period. 

True

Exam #2

True or False

The tail portion of a trilobite is known as the cephalon. 

False!

The head portion is known as the "cephalon"

Exam #2

Definition

Coarse mine waste rock from pre-1930 (local distribution near source).

Jig Tailings

exam #2

Definition

Complex cells with a nucleus containing genetic material.

Eukaryote

exam #2

Definition

Uppermost stratigraphic unit of the Belt Supergroup

Missoula

exam #2

Definition

Cambrian transgressive event.

Sauk

Exam #2

Definition

Tectonic trough thought to represent the failed arm of a triple-junction rift center

Aulacogen

Exam#2

Definition

Simple cells with no nucleus and asexual reproduction.

prokaryotes

exam #2

Definition

Slightly metamorphosed claystone or shale.

Argilite

exam #2

Definition

bizarre Burgess Shale creature with many spikes.

Hallucigenia

exam #2

Definition

late Proterozoic diamictite-bearing unit in S.E. Idaho

Pocatello Formation

exam #2

Definition

Major transgression during Ordovician time.

Tippecanoe

exam #2

Definition

Fine-grained mine waste, consisting of powedered rock in liquid (far reaching down-streams)

floatation slimes

exam #2

Definition

intracratonic basin beginning in early Paleozoic time.

Williston

exam #2

Definition

Cambrian rock unit important in local cement production.

Lakeview Limestone

exam #2

Definition

White, resistant basal Ordovician sands in central idaho

Kinnikinnic Quartzite

exam #2

Definition

Release dissolved zinc highly toxic to aquatic life.

Sphalerite

exam #2

Multiple Choice

The oldest unit of the Belt Supergroup is:

• The missoula group
• The ravalli group
• The piegan group
• the revett formation
• the prichard formation

The prichard formation.

exam #2

Multiple Choice

Plants became new inhabitants of the land during this period of Paleozoic time:

• Mississippian
• Pennsylvanian
• Ordovician
• Devonian
• Cambrian

Cambrian

exam #2

Multiples Choices

These microfossils resemble tiny teeth and are important index fossils in Paleozoic rocks:

• Conodonts
• Acritarchs
• Graptolites
• Crinoids
• Brachiopods

Conodonts

exam #2

True False

Eruptions of the Columbia River basalts resulted in extensive global extinction event.

False

exam #4

True False

Dark tonalites are common along the east side of the Idaho batholith intrusion complex. 

False.

exam #4

True False

The Western Snake River Plain was formed directly by volcanic eruptions from the yellowstone hotspot. 

False

exam #4

True False

The western Cascade mountains are older than the Coast Range. 

False.

exam #4

True False

The Columbia River Basalts were erupted from a series of fissures or tensional cracks during Miocene tim. 

True.

Exam #4

True False

The Imnaha Formatino is the oldest unit of all the Columbia River Basalts. 

True

exam #4

True

exam #4

True False

The Atlanta Lobe (Idaho Batholith) is younger than the Bitterroot Lobe. 

False.

The Atlanta lobe is oldest

exam #4

True False

The chimney of a magma plume is much narrower than the plume head.

True.

exam #4

True False

The Baker Terrane represents the subduction zone trench sediments of the exotic terrane in Hells Canyon. 

True

Exam #4

Multiple Choice

The most voluminous and widespreadunit of the Columbia River basalts is the:

• Grande Ronde
• Saddle Mountains
• Wanapum
• Imnaha
• Craters of the Moon

Grande Ronde

#4

Multiple Choice

Which of the following is not characteristic of Tertiary plutons in central Idaho:

• Relatively shallow depths of emplacement
• myarolitic(low pressure) cavities
• smoky quartz crystals
• Wide contact metamorphism border zones
• Pink granites

Wide contact metamorphism border zones

#4

Multiple Choice

In a cross-sectional view, the Idaho batholith would resemble:

• a balloon
• a thick column
• a thick sill
• a thick dike
• a sphere

a balloon

#4

Multiple Choice

The most commonly accepted idea for the outpouring of Columbia River Basalts is that they are a direct result of:

• the emergence of a large Miocene mantle plume beneath the area
• the impact of a huge asteroid that punched completely through the earth's crust
• Crustal extension in the area, forming cracks perpendicular to the direction of stretching
• Extreme compression along the western margin of North America

Crustal extension in the area forming cracks perpendicular to the direction of stretching.

Exam #4

Multiple Choice

A body of intrusive rock more than 40 square miles in surface area is known specifically as a:

• Stock
• Dike
• Pluton
• Batholith
• Sill

Batholith

exam #4

Multiple Choice

A chaotic assemblage of large blocks mixed with deformed and metamorphosed fine-grained sediments (as in the Fransiscan Terrane) is known as

• Flysch
• Shale
• Conglomerate
• Melange
• Turbidite

Melange

exam #4

Multiple Choice

The laste three major eruption in the Yellowstone area have been of this composition:

• andesitic
• dacitic
• rhyolitic
• syenitic

rhyolitic

exam #4

Multiple Choice

The general term for any intrusive igneous body, regardless of size, is:

• stock
• pluton
• sill
• batholith
• dike

pluton

exam #4

Multiple Choice

The key piece of evidence that some of the Hells Canyon rocks originated in tropical latitudes was the presence of:

• pillow basalts
• basaltic lava flows
• coral reefs
• metamorphic rocks
• granitic rocks

coral reefs

exam #4

Multiple Choice

The Owyhee area of southwestern Idaho is notable for extensive outcrops of this volcanic rock related to the early stages of Yellowstone hotspot migration:

• andesite
• basalt
• granodiorite
• rhyolite
• dacite

rhyolite

#4

Definitions

 Huge wolf-like predator of Tertiary times

Andrewsarchus

exam #4

Definitions

 Seamounts with flat tops from wave erosion

Guyots

#4

Definitions

 Latest Cretaceous and Tertiary block faulting deformation.

Laramide Orogeny

#4

Definitions

 Upthrown block mountains of basin and range province.

Horsts

exam #4

Definitions

 mother of all sloths, late Cenozoic time.

Megatherium

exam #4

Definitions

 Huge, ill-tempered "super-pigs" of the Tertiary

Entelodonts

exam #4

Definitions

 Down-dropped fault blocks of the Basin and Range province

Grabens

#4

Definitions

Relatively shallow Cretaceous thrusting and folding.

Sevier Orogeny

#4

Definitions

 Intrepid U.S. Dinosaur and mammal collector in Mongolia. Basis for Indiana Jones.

Roy Chapman Andrews

#4

Definitions

Cretaceous unit of black shales of the Inland Sea.

Mowry Formation

#4

Joseph Leidy

#4

Rudists

#4

Multiple Choice

The Miocene Columbia River basalts typically weather to a redder, rustier color than younger basalts from Quaternary time because:

• Contain more iron
• Submerged in lakes
• Miocene climate wet and warm
• Buried deeply before being exposed
• They are much older

Wet and warm climate

#4

Multiple Choice

Which of the following is currently thought to be the strongest driving force for tectonic plate movement?

• slab pull into subduction zones
• ridge push at mid-ocean ridges
• magma bouyancy
• hotspot drive
• gravity sliping away from spreading ridges

Multiple Choice

Precambrian time represents about this much of all geologic time since the formation of the earth?

• 10%
• 25%
• 50%
• 75%
• 90% 

90%

exam #1

Multiple Choice

When oceanic crust is in tectonic collision with the other oceanic crust, _____ will form.

• A volcanic island arc
• A mass of continental crust
• a transform margin
• rift zone
• a mid-ocean spreading ridge system 

A volcanic island arc.

exam #1

Multiple Choice

The oldest, generally crystalline rocks comprising the interiors the interiors (cores) of continents are collectively known as the:

• platform
• shield
• craton
• lithosphere
• asthenosphere 

Multiple Choice

When compared to continental crust, oceanic crust is generally:

• thicker
• lighter
• more dense
• much cooler
• much older 

more dense

exam #1

Multiple Choice

Archean sedimentary rocks are mostly composed of:

• extensive limestone deposits
• fine-grained mudstones
• very mature (clean) quartz sandstones
• immature coarse grained angular gravels and sands
• iron-oxide deposits