Geology final exam

The Cenozoic is the time of:

– Adaptive radiation of the mammals
– Cooling of the Earth's climate resulting in the Ice
Ages
– Evolution of humans

The Cenozoic Era consists of three periods:

– Quaternary (youngest)
– Neogene
– Paleogene (oldest)

North America
During Paleogene

Presence of mountain and lakes along west coast because of subduction zones.

Eocene Green River Formation is a lake deposit
during “hot-house” world, contains.....

richest oil shale deposit in the world.

Basin and Range province is dominated by up-faulted mountain ranges and down-
faulted basins, likely due to......

Miocene crustal extension and normal faulting, related to plate
movements along Pacific coast, particularly San Andreas fault.

The Grand Canyon formed because of?

Colorado Plateau Uplift (remember colorado river contribution)

Colorado Plateau was repeatedly raised
during Pliocene and...

Extensive erosion occurred due to
uplift, generating Grand Canyon.

Sierra Nevada Mountains are in

California (Sierra Nevada batholith)

A chain of explosive volcanoes in northwestern USA started ~16 Ma ago,
similar to Hawaiian Islands

Yellowstone Hotspot

What's Happening around the world? Himalayan Mountains are the........

longest in the world, created by the Indian Plate colliding with Asia continental plate.

East African Rift - ?

Formation of Rift Valleys of East Africa
during NEOGENE
– indicate a continent breaking up by a normal fault, extension causes volcanoes and lakes.

Messinian Salinity Crisis (Mediterranean drying out)

Sea level drop due to glaciation, led to isolation of basin (land locked), led to development of thick evaporites (gypsum, halite)

Sudden cooling in the ________ created the _______ ice sheet

Oligocene, Antarctic (South Pole)

North Pole ice happened with the second drop in temperature around the ________

Pleistocene (Quaternary)

Pleistocene Ice Age

Repeated interglaciation of northern ice sheets (greenland)

10-degree temperature drop at end of Cretaceous or....

end of Mesozoic "Greenhouse" condition

Circumpolar currents isolated Antarctica from warmer waters
leading to cooling of Antarctica and building of.......

south-pole ice-sheet

Temperatures dropped dramatically around ......

Eocene-Oligocene boundary

Hot house conditions were replaced by Ice house conditions from...

Oligocene to present.

North Pole -
South Pole -

Greenland ice sheets
Antarctic ice sheets

Pleistocene Ice Age
• Brief warming during early Pliocene suddenly
reversed with the start of

the Northern
Hemisphere glacial cycles at 3.2 Ma ago (Pleistocene Ice Age)

Pleistocene Ice Age -

extensive glaciation(continental glaciers covering North America and Europe) and development of North Poles

Result of Pleistocene Ice Age -

Extensive sea level drop, led to the exposure of land bridges (Bering straight) and migration of mammals, including humans.

Milankovitch Cycle

hypothesis that temperature
fluctuations is related to Earth's orbital oscillations.
– affecting the amount of solar radiation received at Earth.

Great Lakes were formed because of the

Ice Age

Cenezoic is the _____

Age of mammals

Late Cretaceous extinction

K-T boundary

Miocene Cooling (start of everything)

Since mid Miocene (15 Ma), Earth started to cool
rapidly
– Cooler Miocene seas sent less water to atmosphere through
evaporation, causing less rainfall on global continents.

Less rainfall led to ___________ expansion which impacted ___________

Grassland
Climate

Because of changing climate it led to _______ mammals

grazing

grazing mammal evolution led to impacts on teeth like

high crowned cheek teeth that continue
to grow at the roots (face length in front of eyes also increased)

Grassland expansion cascaded upward through food
webs:

– Rats/mice and songbirds eat grass seeds
– Snake eat rats/mice and eggs/chicks of songbirds

During Pleistocene glaciation many ______ and ______ mammals existed

Large and trunk bearing

Last glaciation was _________

20,000 y. ago.

Development of
Panama (Panamanian) land
bridge ~3 m.y. ago
(during Late
Pliocene)

– led to the
migration of
mammals between
North and South
America.

Bering land bridge existed
between North America
and Eurasia during ________, now occupied by the ________

Pleistocene
Bering Sea

Why is climate change man-made (anthropogenic)?

Greenhouse Gases CO^2 + CH^4 (Carbon Dioxide, Methane)

Exponential growth of CO^2 after ________

Industrial Revolution

______ increase of CO^2 in atmosphere

50%

How do we know what kind of C0^2?

Measure gas bubbles found in ice samples

Global surface temperatures have increased which have led to the

decrease of snow cover and floating arctic ice in northern hemisphere (Greenland)

Melting of sea ice will not rise sea level, only melting of ______ will increase sea level

land ice

melting of sea ice has opened

arctic passage

Mountain glaciers are _______ and ________ fast

melting, disappearing

Gas hydrates (frozen methane) located within ocean sediments will lead to

a positive feedback cycle because of global warming

Earth warming will lead to.....

Intense and more frequent storms, as well as sea level rise affecting coastal cities

We are currently in the 6th (Anthropogenic) .....

mass extinction

Who are humans?

Homo sapiens

Primates are defined by characteristics adapted for living in trees

Good shoulder joints for swinging from branches.
– Large eyes
– Excellent eye-hand coordination:
– Larger brains than other mammals

Primates, appeared in

Paleocene (55 Ma
ago) after K-T
extinction event.

Geographic distribution of primates?

Along the equator where there are more trees.

What separates hominins from other primates?

Bipedalism

When did hominins split off from other primates?

6 million y ago. split off

What other primates are closely related to us?

chimps

Ardi -

4.4 ma old
biped
big toe for back to trees

Lucy -

biped

Homo erectus - brain size ______
Homo sapien - brain size _______

brain size doubled (developed stone tools)
brain size tripled

Neanderthals - we _____ with them

bred

We all share neanderthal DNA besides

Africans

We all link back to a single tribe in ______

Africa

Homo erectus was the first to leave ______

Africa

Drivers of human evolution _______

climate change

Humans first set foot in new world ________

15,000 y. ago

Hominin fossil found in _____
Why? vegetation _____

East African Valley, change

Hypothesis of human evolution

bipedalism

As trees were getting further in distance, we were forced to walk upright because it was more ________

energy efficient

Tectonic Rift hypothesis

created more valleys and savannahs