the precambrian earth to the present
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The Precambrian Earth to the present. 4.5 Billions years in 2 weeks!. PowerPoint Notes created by S. Koziol Date : 12/30/2013 Revised : ?/?/??. Objectives Slides 2-21. Describe the evidence used to determine the age of the Earth - PowerPoint PPT PresentationTRANSCRIPT
The Precambrian Earth to the present.
4.5 Billions years in 2 weeks!
PowerPoint Notes created by S. KoziolDate : 12/30/2013 Revised : ?/?/??
Objectives Slides 2-21
DescribeDescribe the evidence used to determine the age of the Earth
UnderstandUnderstand why scientist theorize that the early Earth was hot.
ExplainExplain the origins of Earth Crust.
DescribeDescribe the formation of the Archean and Proterozoic continents.
DescribeDescribe the formations of Earth’s atmosphere and oceans.
IdentifyIdentify the origins of oxygen in the atmosphere.
ExplainExplain the evidence that oxygen existed in the atmosphere during the Proterozoic.
DescribeDescribe the experimental evidence of how life developed on Earth.
DistinguishDistinguish between prokaryotes and eukaryotes.
IdentifyIdentify when the first multicellular animals appeared in geological time.
Earth & our Solar SystemMost astronomers agree that the solar system, including
Earth, formed all at once, and therefore Earth and meteorites should be about the same age.
Earth’s Crust
Earth’s earliest crust likely formed as a result of the cooling of the uppermost mantle.
Oldest MineralThe oldest known mineral on Earth is zircon.
Laurentia (North American Craton)
Ancient continent that contained core of modern-day North America
Precambrian shield
Continental core of Archean and Proterozoic rock. aka Canadian shield - The Precambrian shield in N.A.
Craton is an old and stable core of the continental crust - the buried and exposed parts of a continental shield together compose it.
Precambrian shield vs. Canadian shield
A Precambrian shield is a continental core of Archean and Proterozoic rock
The Canadian Shield is the Precambrian shield of North America.
Orogens
Orogens are seams where microcontinents were joined together. These seams are belts of deformed rocks that form mountain ranges.
Ozone & O2
The ozone layer that filters ultraviolet radiation originated from oxygen produced by stromatolites.
OutgassingThe process by which volcanoes vent water
vapor, carbon dioxide, nitrogen, and other substances is called outgassing.
PhotosynthesisCyanobacteria use the process of photosynthesis
to produce energy, and oxygen is given off as a waste product.
Banded iron formationThese are deposits consisting of alternating bands of chert
and iron oxide.
Red beds
Sedimentary rocks younger than 1.8 billion years that are colored by the iron oxides in them.
Start of lifeAmino acids have been found in the waters of
hydrothermal vents, suggesting that proteins and nucleic acids could have formed there during the Archean.
Miller and Urey
Miller and Urey demonstrated that the basic building blocks of life were most likely present on Earth during the Archean.
Miller and Urey (continued)
Heat, cyanide, and certain clay minerals can cause amino acids to join together in chains.
Prokaryote.An organism composed of a
single cell that does not contain a nucleus and is the simplest kind of cell is a prokaryote. Prokaryotes belong to the Kingdom Monera.
Prokaryote vs. EukaryoteA prokaryote is a simple
organism composed of a single cell, which does not contain a nucleus.
A eukaryote is an organism that is composed of multiple cells, which contain nuclei and are more complex and larger than those of prokaryotes.
ExtinctionsA major extinction of acritarchs occurred near
the end of the Proterozoic, in which widespread glaciations may have played a critical role.
Objectives Slides 23-38 DescribeDescribe the paleogeography of Laurentia.
DiscussDiscuss the concept of a passive margin.
DescribeDescribe the Cambrian fauna.
DescribeDescribe the Middle Paleozoic paleogeography.
ExplainExplain the concept of an active margin and the formation of a clastic wedge.
DescribeDescribe the Middle Paleozoic fauna.
DefineDefine the concept of mass extinction.
DescribeDescribe the formation of Pangaea.
ExplainExplain how cyclotherms formed.IdentifyIdentify the importance of
amniote eggs.DiscussDiscuss the causes of the Late
Permian mass extinction.
Paleogeography
Ancient geographic setting of an area.
LaurentiaDuring the Cambrian, Laurentia was covered by
a sea.
Laurentia - PrecambrianOn Laurentia, large, sandy beaches formed when sand-sized
fragments of quartz were weathered from the rocks of the Precambrian Shield and transported to the shoreline.
Passive MarginWhen there is no tectonic activity along the
edge of a continent, the edge is referred to as a passive margin.
Cambrian explosion
During the Cambrian explosion, all but one of the major marine phyla appeared.
Cambrian explosion (continued)
The Cambrian explosion was marked by great diversity of life, including the development of animals with skeletons.
Burgess Shale
Burgess Shale - Contains fossils of soft-bodied Cambrian organisms
Evidence of past lagoons
Fragile organisms can live in a lagoon, which is the calm area behind a reef.
Reefs
An organic reef is a structure composed of carbonate skeletons made by living organisms, such as coral.
Taconic Orogeny
Taconic Orogeny - Mountain-building event named for the mountains of eastern New York State
Clastic Wedge OriginsA triangular-shaped deposit composed of
sediment eroded from adjacent mountains is called a clastic wedge.
The following provides evidence of the Taconic Orogeny:
• angular unconformities• clastic wedges• igneous intrusions
Vascular PlantsThe ability to transfer water through stems and
stalks characterizes vascular plants.
Ancestral Rockies
Mountain range in present-day Colorado formed by inland uplift.
Mountain Building
The Late Paleozoic was a time of active mountain building.
Cyclothems
The series of transgressions and regressions that produce cyclothems were likely produced by glaciations.
Objectives Slides 40-59 ExplainExplain the breakup of
Pangaea.DistinguishDistinguish between the
different characteristics of Mesozoic Orogenies.
Describe Describe how paleontologists distinguish among reptile, dinosaur and mammal fossils.
DescribeDescribe the type of tectonism that characterized the Cenozoic orogeny.
Understand Understand the extent of glaciation that occurred in N.A..
DiscussDiscuss the changes in animals in N.A. during the Cenozoic.
IdentifyIdentify the characteristics of primates.
ExplainExplain what separates hominids from the other hominoids.
200 MYAAs North America rifted from Europe and Africa, a
continuous rift system called the Mid-Atlantic ridge was formed.
New OceansAs Pangaea split apart, the rifts flooded to form
new oceans.
Pangaea break-up
Pangaea probably broke apart because it held heat beneath it, which caused the continent to expand and then fracture and break apart.
Mesozoic orogeniesAs a result of the earliest of the Mesozoic orogenies
in North America, large bodies of granite called batholiths exist throughout the Cordillera.
Mesozoic orogenies (continued)
Orogenic events at the end of the Mesozoic uplifted massive blocks of crust to form the Rocky Mountains.
First Angiosperms
Angiosperms - Seed-bearing plants that have flowers
Archaefructaceae
PhytoplanktonTiny, ocean-dwelling organisms called
phytoplankton made up the base of the food chain during the Mesozoic.
Vertebrates and Invertebrates from among the modern fauna.
Vertebrates: bony fishes, sharks, aquatic reptiles, and aquatic mammals
Invertebrates: crabs, lobsters, shrimps, sponges, sea urchins, modern corals, snails, and clams.
Mesozoic ammonitesFossils of ammonites are often used as index
fossils because these marine animals were widespread and abundant during the Mesozoic.
Early Mammals
Early mammals with a single jawbone arose from mammal-like reptiles.
SauropodThe largest land animals that ever lived were the
quadrupedal, plant-eating sauropods.
S.W. U.S. tectonism
The subduction of the East Pacific Rise coincides with pull-apart tectonism in the southwestern United States.
Pliocene ice ageAs the Pliocene ice age began, great savannas
became arid land and many savanna mammals became extinct.
Pliocene ice age (continued)
The change of climate caused many of the savanna mammals to become extinct. New animals came to populate the land, including sabre-toothed cats, mammoths, giant vultures, giant ground sloths, and huge wolves.
Pliocene ice age (continued)
During the Pliocene, the water of the Arctic Ocean began to freeze to form an arctic ice cap. Glaciers from the arctic advanced and retreated in at least four stages over North America. Glaciers extended as far south as the present-day Ohio and Missouri Rivers.
Pliocene ice age (continued)
The southernmost point to which glaciers advanced in North America is marked by the paths of the Ohio River and the Missouri River.
Eocene Mammals
Most of the currently living groups of mammals had appeared by the Eocene.
Primate Traits
Primates - Mammal possessing specialized traits related to arboreal lifestyle
Primate Traits (continued)
Two important anatomical traits of all primates are an opposable thumb and forward-facing eyes.
Us (you & I)Homo sapiens - Modern human species