Geology 106 CH 22

Triassic (245 Ma) Jurassic (208 Ma) Cretaceous (144 Ma)

Triassic (245 Ma) Jurassic (208 Ma) Cretaceous (144 Ma)

Arrange different periods of Mesozoic in correct order and timeline.

reptiles (dinosaurs), mammals, birds, flowering plants

Which were most important evolutions in Mesozoic?

1 Triassic 2 Jurassic 3 Cretaceous 4 Cenozoic

Identify different stages of the breakup of Pangaea according to the periods of Mesozoic era.

Triassic

rifting of Laurasia and Gondwana

Jurassic

breakup of East Gondwana

Cretaceous

South America and Africa separate

Cenozoic

Greenland separates

rising sea level; separated the continents

What is ‘Rifting’? Describe its role in the breakup of Pangaea.

Tethys Sea

Identify the source of water flow in the Atlantic ocean and Gulf of Mexico during the breakup of Pangaea.

dry area with salt and gypsum deposition

Gulf of Mexico contains the formation of thick evaporite deposits from Mesozoic era. What type of environments were the reasons behind those formations?

Jurassic --India had broken away from the landmass

When did Australia and Antarctica detach from each other?

Greenland separated from Europe and North America

What happened during the final stage of Pangaea’s breakup?

False

Statement: During the Early and Middle Triassic, coarse detrital sediments derived from erosion of the recently uplifted Appalachian mountains made a large lowland area. (True/False)

• Coarse clastics

• Up to 6 km thick

• High content of unweathered feldspar

• Weathering of granitic highlands bordered by fault basins

• Terrestrial conditions (Mud cracks, Dinosaur footprints)

What is Newark group?

volcanism

Why numerous dykes and sills were found in Newark group?

The Gulf Coastal region was the site of major evaporite accumulation during the Jurassic as North America rifted from South America.

a column of salt has risen toward the surface because it has a lower density than the rocks above it.

How did salt domes appear in Gulf coast region? Describe reasons of their ‘dome’ shape.

True

Statement: Salt domes work as possible petroleum traps. (True/False)

Upper Cretaceous, deposition of chalk

When did major transgression happen in Mesozoic? What type of environment was widespread in the Gulf coast region due to this major transgression?

1 Sonoma 2 Nevadan 3 Sevier 4 Laramide

How many tectonism processes occurred in the western region of North America during the Mesozoic era? Arrange them according to the timeline.

the cause of the Sonoma, Nevadan, Sevier, and Laramide orogenies was the changing angle of subduction of the oceanic Farallon plate under the continental North American plate

What was the driving force of Mesozoic tectonics?

deep ocean volcanic rocks and sediments that were in a submarine trench

What types of rocks are contained in the Franciscan complex?

batholiths; during the Cretaceous, the angle of the subducting Farallon plate became less steep and the orogeny moved eastward into Nevada and Idaho.

What type of rocks were formed during Nevadan orogeny? What was the reason behind this?

False

Statement: Regions affected by volcanic activities are not affected by the angle of subducting plate. (True/False)

the changing angle of subduction of the oceanic Farallon plate under the continental North American plate

What was the main reason of Sevier orogeny?

consisted of several different mountain- building events that overlapped in time. They resulted from the North American plate overriding the subducting Farallon plate

Note down the specific regions that were affected by different Cordilleran orogeny processes.

The Late Triassic Chinle Formation with its petrified wood

the Early Jurassic Navajo sandstone with its wind-blown desert crossbeds are famous formations of this area

When did Chinle formation and Navajo sandstone form? What are their characteristics?

Regression of Sundance Sea

• Meandering rivers, flood plains

• 70 species of dinosaurs

• Including biggest ever existed

How did Morrison formation develop? Why Morrison formation is famous?

True

Statement: More than 25% of the North American western margin originated from the accretion of terranes. (True/False)

coal, petroleum, uranium, gold, and copper

What are the resources contained by Mesozoic rocks?

formed during the Mesozoic and Cenozoic along the western margins of North and South America

Locate world’s largest copper deposits. When did they form?

Bivalves, Cephalopods, Gastropods

What were the Molluscs classes of Mesozoic era?

Belemnites (squid-like animal with internal shell)

Which is used as the guide fossil for Triassic-Cretaceous?

Scleractinian corals and rudist

Which was important reef builders throughout the Mesozoic era?

microorganisms, including foraminifera (single-celled consumers) and primary producers, diversified

Describe primary consumers and producers in the Mesozoic seas.

the flowering plants, evolved during the Early Cretaceous, diversified rapidly, and soon became the dominant land plants

Production of seeds, fruits, nuts Today: 250,000- 300,000 species! 90% of all land plants

What is Angiosperms? What are the advantages of flower plants?

crocodiles, dinosaurs, birds, and flying reptiles

Archosaurs are ancestors of several animals. List those animals that evolved from Archosaurs.

Draw the pelvic structure of Saurischia and Ornithischia.

Theropods - bipedal carnivorous dinosaurs Sauropods - giant quadrupedal herbivorous dinosaurs

What are the differences between Theropods and Sauropods?

Theropods: Allosaurus, Coleophysis, Compsognathus, Deionchyus, Tyranosaurus, Velociraptor

Sauropods: Apatosaurus, Brachiosaurus, Camarasaurus, Diplodocus, Titanosaurus

List some familiar genera of Theropods and Sauropods.

front teeth replaced by beak suitable for cropping vegetation

Why ornithischian dinosaurs had beak?

defense

What was the use of tail spikes in Stegosaur?

Ankylausor, Ceratropsia (Triceratops)

Which type of dinosaurs had horns?

• Numerous openings in the bones to allow more blood flow

• Eating a lot to keep their metabolic rate up

• A large brain requires a constant body temperatur

• 4-chambered heart

What were the possible reasons to believe that dinosaurs were warm-blooded animals?

birds

Are pterosaurs probable ancestor of birds or bats?

• heavy-bodied marine reptiles that probably came ashore to lay eggs

• Late Jurassic

• Predatory marine reptile

• Paired fins, good swimmers

• No armor: very vulnerable

• Survived by sight, speed, camouflage colors

• Laid eggs like sea turtle in sand

Describe Plesiosaurs

they attract animal pollinators, like insects

Why the evolution of flowers was important?

True

Pterosaurs are the probable ancestor of the birds.

dentary and squamosal

The jaw-skull point in mammals is between ________.

True (?)

High concentration of iridium in the Cretaceous-Paleogene boundary is a possible postulation for the impact of a big meteorite because some meteorites contain high concentration of iridium. A. True B. False

True

In the case of a salt dome, a column of salt has risen towards the surface because it has a lower density than the rocks above it. A. True B. False

Cretaceous

When reefs were widespread in the Gulf Coast region?

True

The various rock types suggest that rocks of the continental shelf, slope, and deep-sea environments were brought together in a submarine trench when North America overrode the subducting Farallon plate. A. True B. False

True

Sevier thrust faults brought older rock strata on top of younger strata. A. True B. False

Nevadan orogeny: Nevada, California, Idaho

According to the effect of different orogeny in different places-

which one is correct?

True

Navajo sandstone is one of the thickest early Jurassic-age wind-blown deposits. A. True B. False