Friday November 11, 2011 (?? ) The Launch Pad Friday, 11/11/11
List the major steps in the development of Earths atmosphere and oceans that lead to life on Earth as we know it today. Earths 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 Earths rocky surface. Products of this weathering were carried to the oceans, thus increasing the salinity of the oceans.. The Launch Pad Friday, 11/11/11 How old is the Universe?
13.6 billion years old How old is the Earth? 4.5 billion years old Summative or Formative
AssignmentCurrently Open Summativeor Formative DateIssued DateDue DateIntoGradeSpeed Last Day Project MoonFeatures F1 10/18 10/21 Quiz 9 S (last 6-wks) 11/2 11/3 11/17 Video WS FearlessPlanet Earth Story F2 11/10 Activity DrawEarths InternalStructure F3 11/8 11/9 10/14 Quiz 10 S1 11/11 12/2 I will be available today after school until 5:00 PM.
Announcements I will be available today after school until 5:00 PM. Latest News In 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 somepoint, 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 Scale
The 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 Scale
Eon Era Period Epoch The Geologic Time Scale The Geologic Time Scale
Figure 11.19 The Geologic Time Scale Activity Make your own Geologic Time Scale, labeling all eons, eras, and periods.Include the epochs at your discretion. In what eon, era, period, and epoch are we now living?
The Launch Pad Wednesday, 10/20/10 In what eon, era, period, and epoch are we now living? The Phanerozoic Eon The Cenozoic Era The Quaternary Period The Holocene Epoch The Geologic Time Scale
Lab The Geologic Time Scale The Launch Pad Thursday, 10/21/10
What are the names of the eons if weconsider there to have been only two in Earths history? The Precambrian Eon and the Phanerozoic Eon If the Earth is millions years old, how many years did each eon occupy? Precambrian 3958 million years, Phanerozoic 542 million years What percentage of Earths history did each occupy? Precambrian 88%, Phanerozoic 12% The Geologic Time Scale
Lab The Geologic Time Scale The Launch Pad Friday, 10/22/10 Great Permian extinction
Name an important factor that caused the Precambrian Eon to change to the Phanerozoic Eon. First organisms with shells and other hard body parts Name 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 Scale
Geologic time is divided into Eons. Precambrian Eon Archean Eon Proterozoic Eon Phanerozoic Eon The Geologic Time Scale
Eons are further divided into Eras. Archean Eon Eoarchean Era Paleoarchean Era Mesoarchean Era Neoarchean Era Proterozoic Eon Paleoproterozoic Era Mesoproterozoic Era Neoproterozoic Era Phanerozoic Eon Paleozoic Era Mesozoic Era Cenozoic Era The Geologic Time Scale
The Phanerozoic Eon is further divided into Periods. 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 Scale
The 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 Much of Earths stable continental crust was created during this time.
The Precambrian Eon The Precambrian Eon, which is divided into the Archean and the Proterozoic Eons, spans about 88% of Earths history. Much of Earths 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 Earths major mountain belts. Supercontinents have also profoundly affected Earths climate over time. Possible configuration of the supercontinent Rodinia
Figure 12.15 It was during the Precambrian Eon that life first began on the Earth.
Although the PrecambrianEon contains some 88% ofEarth's history, its fossilrecord is poor becauseorganism were soft-bodiedduring this time, resultingin little remaining evidence. The Precambrian Eon The majority of Precambrian fossilsarestromatolitesthat are oftenheavily metamorphosed or deeplyburied. However, preserved cells have beendiscovered at selective sites, such as the 2.0Ba Gunflint Formation Jasper stromatolitesfrom Gunflint Formation near Mackies,northern Ontario. The Precambrian Eon The earliest life forms were prokaryotes thatevolved in the seas, possibly as early as 3.8 Ga. The first primitive prokaryotic single-celled organisms appeared in the oceans in the form of bacteria (eubacteria or Achaea). The Precambrian Eon Earthsfirst 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 endosymbiosisis 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 crustal provinces then accreted into cratons.
The Launch Pad Monday, 10/25/10 Describe the process by which continents were formed in the Precambrian Eon. Volcanic island arcs and oceanic plateaus rose up in the ancient seas due to the upwelling of magma from the upper mantle. The action of plate tectonics caused the arcs to accrete into crustal provinces. The crustal provinces then accreted into cratons. The cratons then accreted to form the foundations of the modern continents. 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.