friday november 11, 2011
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Friday November 11, 2011. (?? ). The Launch Pad Friday, 11/11/11. List the major steps in the development of Earth’s atmosphere and oceans that lead to life on Earth as we know it today. Earth’s primitive atmosphere was formed by a process called “outgassing.” . - PowerPoint PPT PresentationTRANSCRIPT
FridayNovember 11,
2011
(?? )
The Launch PadFriday, 11/11/11
List the major steps in the development of Earth’s atmosphere and oceans that lead to life on Earth as we
know it today.Earth’s primitive atmosphere was formed by a process called
“outgassing.” Water vapor condensed to form clouds and rainwater that formed
the oceans. Oxygen levels in the atmosphere steadily increased as a result of photosynthetic bacteria in the
ocean.Outgassing produced acidic conditions that caused an accelerated rate of
weathering of Earth’s rocky surface.Products of this weathering were carried to the oceans, thus increasing the salinity
of the oceans..
The Launch PadFriday, 11/11/11
How old is the Universe?
How old is the Earth?
13.6 billion years old
4.5 billion years old
Assignment Currently Open
Summative or Formative
Date Issued
Date Due
Date Into
Grade Speed
Last Day
Project – Moon Features F1 10/18 10/21
Quiz 9 S (last 6-wks) 11/2 11/2 11/3 11/17
Video WS – Fearless Planet – Earth Story F2 11/3 11/10
Activity – Draw Earth’s Internal Structure
F3 11/8 11/9 11/10 10/14
Quiz 10 S1 11/10 11/10 11/11 12/2
AnnouncementsI will be available
today after school until 5:00 PM.
Latest NewsIn 2006, a farmer found a meteorite buried
in a hillside in the Missouri town of Conception Junction (population 202).
Only now has the out-of-this-world value of the space rock discovery come to light.
Geochemist Randy Korotev of Washington University in St. Louis and his colleagues have identified the space rock as a rare
type of pallasite meteorite worth about $3.4 million, the researchers said today. Only
19 other pallasites had ever been found in the United States. The meteorite traveled a long road to find its way into Korotev's hands. Researchers think this meteorite was once part of an asteroid that orbited the sun in the asteroid belt between Mars and Jupiter. At some point, this fragment was knocked into an orbit that crossed
Earth's path, and it was pulled down to our planet by gravity.
The Geologic Time Scale
The Geologic Time ScaleThe geologic time scale divides geologic history into units.Subdivisions of the scale:
• Eon - greatest expanse of time. There are four eons• Phanerozoic (“visible life”) – the most recent eon • Proterozoic • Archean • Hadean – the oldest eon
• Era - Subdivision of an eon. Example: Eras of the Phanerozoic eon • Cenozoic (“recent life”) • Mesozoic (“middle life”)• Paleozoic (“ancient life”)
• Eras are subdivided into periods.• Periods are subdivided into epochs.
The Geologic Time ScaleoEonoEra
oPeriodoEpoch
The Geologic Time Scale
Figure 11.19
The Geologic Time Scale
ActivityMake your own Geologic Time
Scale, labeling all eons, eras, and periods. Include the epochs at
your discretion.
The Launch PadWednesday, 10/20/10
In what eon, era, period, and epoch are we now living?
The Phanerozoic EonThe Cenozoic Era
The Quaternary PeriodThe Holocene Epoch
LabThe Geologic Time Scale
The Launch PadThursday, 10/21/10
What are the names of the eons if we consider there to
have been only two in Earth’s history?If the Earth is 4 500
millions years old, how many years did each
eon occupy?What percentage of Earth’s history did
each occupy?
The Precambrian Eon and the Phanerozoic
EonPrecambrian – 3958
million years, Phanerozoic – 542
million yearsPrecambrian – 88%, Phanerozoic – 12%
LabThe Geologic Time Scale
The Launch PadFriday, 10/22/10
Name an important factor that caused the
Precambrian Eon to change to the
Phanerozoic Eon.
First organisms with shells and other hard
body partsName an important
factor that caused the Paleozoic Era to change
to the Mesozoic Era.
Great Permian extinction
Name an important factor that caused the
Mesozoic Era to change to the Cenozoic Era.
Extinction of dinosaurs and many
other species
The Geologic Time ScaleGeologic time is divided into Eons.
1. Precambrian Eon
a) Archean Eon
b) Proterozoic Eon
2. Phanerozoic Eon
The Geologic Time ScaleEons are further divided into Eras.
1. Archean Eon• Eoarchean Era• Paleoarchean Era• Mesoarchean Era• Neoarchean Era
2. Proterozoic Eon• Paleoproterozoic Era• Mesoproterozoic Era• Neoproterozoic Era
3. Phanerozoic Eon• Paleozoic Era• Mesozoic Era• Cenozoic Era
The Geologic Time ScaleThe Phanerozoic Eon is further divided into Periods.
1. Phanerozoic Eon• Paleozoic Era
• Cambrian Period• Ordovician Period• Silurian Period• Devonian Period• Carboniferous Mississippian Period• Carboniferous Pennsylvanian Period• Permian Period
• Mesozoic Era• Triassic Period• Jurassic Period• Cretaceous Period
• Cenozoic Era• Tertiary Period• Quaternary Period
The Geologic Time ScaleThe Cenozoic Era is further divided into Epochs.
• Cenozoic Era• Tertiary Period
• Paleocene Epoch• Eocene Epoch• Oligocene Epoch• Miocene Epoch• Pliocene Epoch
• Quaternary Period• Pleistocene Epoch• Holocene Epoch
The Precambrian Eon The Precambrian
Eon, which is divided into the Archean and the Proterozoic Eons, spans about 88% of
Earth’s history. Much of Earth’s stable continental crust was created during this time.Partial melting of
the mantle formed volcanic island arcs and ocean
plateaus.
The Precambrian Eon These crustal
fragments collided and accreted to
form larger crustal provinces.
Larger crustal areas were
assembled into larger blocks
called cratons.Cratons form the core of modern
continents.
Formation of Continental Crust
According to one model, the growth of large continental masses were accomplished through the collision and
accretion of various types of terrains, including volcanic arcs and oceanic plateaus.
The Extent of Crustal Materials Remaining From the Archean and Proterozoic Eons
Map showing the major geological provinces of North America and their ages in billions of years
(Ga). It appears that North America was
assembled from crustal blocks that were joined
by processes very similar to modern plate
tectonics. These ancient collisions produced
mountainous belts that include remnant island
arcs trapped by colliding continental fragments.
The Precambrian Eon The
Supercontinents The supercontinents
were large landmasses that consisted of all, or
nearly all, of the existing continents.
Pangaea was the most recent supercontinent, but perhaps an even larger one, Rodinia,
preceded it.Splitting and
reassembling of supercontinents have
generated most of Earth’s major mountain
belts.Supercontinents have
also profoundly affected Earth’s climate over
time.
Possible configuration
of the supercontinent
Rodinia
Figure 12.15
The Precambrian Eon It was during the Precambrian Eon
that life first began on the
Earth.Although the
Precambrian Eon contains some 88%
of Earth's history, its fossil record is poor because organism were soft-bodied during this time, resulting in little
remaining evidence.
The Precambrian Eon The majority of Precambrian fossils are stromatolites that
are often heavily metamorphosed or deeply
buried.However, preserved cells have been discovered at selective sites, such as the 2.0 Ba Gunflint Formation Jasper stromatolites
from Gunflint Formation near Mackies, northern Ontario.
The Precambrian Eon
The first primitive prokaryotic single-celled organisms appeared in the
oceans in the form of bacteria
(eubacteria or Achaea).
The earliest life forms were prokaryotes
that evolved in the seas, possibly as early as 3.8 Ga.
The Precambrian Eon Earth’s first living organisms were probably
chemotrophs existing in an anoxic world and producing H2S or CO2.
The Precambrian Eon Nearly 3.5 Ga, photosynthezing
cyanobacteria began releasing oxygen into the atmosphere as a by-product of the
process of photosynthesis.
The Precambrian Eon The first multi-cellular organisms appeared
toward the end of the Precambrian Eon, sometime prior to 542 Ma.
The Precambrian Eon When the eukaryotes (single-celled
organisms with a nucleus) evolved through endosymbiosis is disputed, with claims as
early as 3.4 Ga, but with less equivocal fossils dating from 1.8 to .8 Ga.
The Precambrian Eon With the eukaryotes comes sexual
reproduction, enabling genetic diversity and the concomitant ability to adapt to and
survive environmental changes.
The Launch PadMonday, 10/25/10
Describe the process by which continents were formed in the
Precambrian Eon.1. Volcanic island arcs and oceanic plateaus rose up in the ancient seas due to the upwelling of
magma from the upper mantle.
3. The crustal provinces then accreted into cratons.4. The cratons then accreted to form the
foundations of the modern continents.
2. The action of plate tectonics caused the arcs to accrete into crustal provinces.
Activity Get your tape from the Lab on the Geologic Time
Scale. On the front side (from Part 1), divide the
Precambrian Eon into Eras. Research what caused the Eras to change and note
this on the tape. On the back side (from Part 2), if you have not done
so already, divide the Phanerozoic Eon into eras, periods, and epochs.
Research what caused the all of the changes and note this on the tape.