History of Earth (Bio 301M)
Geologic
History of Earth - See cross-section of earth here and here.
- Continental
drift
- plate tectonics (See links below)
(OH) and (OH)
- -
types of boundaries (OH) and the mid-oceanic
ridge (OH)
- -
The mid-Atlantic
ridge
and the repeated reversal of the earth's magnetic field
- convection cells in the mantle
(OH) similar to those
in boiling water (OH)
- Pangaea
- -
Where'd
that Indian
plate
go?
- -
California - into the sea? The San Andreas fault - a map and a picture.
- Wegener's evidence (1) Africa and S. America
(2) biogeograpy (3) glacial deposits
- -
See drawings from 1858 by Antonio Snider-Pellegrini before and after the breakup of Pangaea,
which was not even named until 1912 (by Wegener).
Alternation between hot & cold climates which resulted in:
- the rising and falling of sea levels
- extension and retreat of ice (glaciers)
Volcanos
- caused "nuclear winters"
- possibly caused mass extinction at
end of Permian when Pangaea formed
- -
some formed at areas other than boundaries. See map of earth's hot spots
and creation of Hawaii
Meteorites
- caused "nuclear winters"
- most important at end of Mesozoic (Cretaceous
extinction - K-T boundary)
- Mass extinctions
A simple but
interesting look at the origin
of the earth and life from NASA.
Visit any
time period
at the Berkeley site. Lots of good pictures.
Geologic time table - simple
one, complex
one (you are not responsible for either one)
PALEOZOIC ERA - Age of fishes (Paleozoic
Ocean Life - images) and a great trilobite
site.
- Cambrian Explosion. More on this here.
- About 570-500 million years ago
- Burgess
shale
Invasion
of Land
- occurred during Silurian
Devonian - first gymnosperms,
insects
Carboniferous - those famous
forests
of the Carboniferous
Permian
- Pangaea formed
- extinction of about 90% of marine and
terrestrial species. Possible causes.
- -
The Permian
Reef Complex
(Delaware Basin) of West Texas - A virtual tour of a Texas site.
- Written
by K.A. Grimm
MESOZOIC ERA - Age of Reptiles 245-65 mya. Discovery
of dinosaurs.
- Triassic
- Radiation of gymnosperms, tree ferns,
invertebrates & reptiles, including dinosaurs
Jurassic
- map of earth at early
Jurassic - about 200 mya
- -
radiation of bony fishes, flying reptiles, some mammals
Cretaceous
- very warm, sea levels high, radiation
of flowering plants, dinosaurs, small mammals
- Extinction of Dinosaurs (K-T
boundary)
(Big blank place on this page - keep scrolling!)
- ended 65 million years ago, most think
caused by asteroid impact (OH)
- -
a great K-T
Boundary site,
complete with a game to play and lots of info!
- -
More on the impact
theory
of mass extinctions.
- -
A great dinosaur
site!
- -
Hot-Blooded
or Cold-Blooded??
- -
A satellite
image
of the Yucatan impact site of that giant asteroid.
- -
An alternative theory of the extinction of the dinosaurs, gradualism,
is presented here.
-
by Bryan Goff, Central Connecticut State University
- -
A NASA site on impact
hazards
of the future!
- -
Levels of iridium in earth's strata.
- -
OH of representative
animals of the Mesozoic
CENOZOIC - Age of mammals
- Ice Ages
- Tertiary 65-2 mya
- Climate cooler, sea levels lower,continents
near current positions
- Radiation of birds, mammals, flowering
plants and insects.
Quartenary 2 mya - present
- Cold clilmate, repeated glaciations,
sea levels low
- Humans evolve, many large mammals go
extinct
- -
The
midwestern U.S., 16,000 years ago.
Human Impact
- We've only been around a few seconds!!
Geologically speaking.
- Global climate
change
- Threats to biodiversity - humans causing
another major extinction event?
- -
OH for representative
extinct North and South American mammals of the Cenozoic
-
Links for
plate tectonics
from USGS:
http://pubs.usgs.gov/publications/text//dynamic.html
from Berkeley:
http://www.ucmp.berkeley.edu:80/geology/tectonics.html
from UT: http://www.ig.utexas.edu/research/projects/plates/plates.mov
from Dinosauria:
http://www.dinosauria.com/dml/maps.htm
