Studied by 4 people
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
Note
Flashcard