Presentation on theme: "The Precambrian Earth to the present."— Presentation transcript:
1The Precambrian Earth to the present. 4.5 Billions years in 2 weeks!PowerPoint Notes created by S. KoziolDate : 12/30/2013 Revised : ?/?/??
2Objectives Slides 2-21Describe the formations of Earth’s atmosphere and oceans. Identify the origins of oxygen in the atmosphere. Explain the evidence that oxygen existed in the atmosphere during the Proterozoic. Describe the experimental evidence of how life developed on Earth. Distinguish between prokaryotes and eukaryotes. Identify when the first multicellular animals appeared in geological time.Describe the evidence used to determine the age of the Earth Understand why scientist theorize that the early Earth was hot. Explain the origins of Earth Crust. Describe the formation of the Archean and Proterozoic continents.
3Earth & our Solar System Most astronomers agree that the solar system, including Earth, formed all at once, and therefore Earth and meteorites should be about the same age.
4Earth’s CrustEarth’s earliest crust likely formed as a result of the cooling of the uppermost mantle.
5Oldest MineralThe oldest known mineral on Earth is zircon.
6Laurentia (North American Craton) Ancient continent that contained core of modern-day North America
7Precambrian shieldContinental core of Archean and Proterozoic rock. aka Canadian shield - The Precambrian shield in N.A.
8Cratonis an old and stable core of the continental crust - the buried and exposed parts of a continental shield together compose it.
9Precambrian shield vs. Canadian shield A Precambrian shield is a continental core of Archean and Proterozoic rockThe Canadian Shield is the Precambrian shield of North America.
10OrogensOrogens are seams where microcontinents were joined together. These seams are belts of deformed rocks that form mountain ranges.
11Ozone & O2The ozone layer that filters ultraviolet radiation originated from oxygen produced by stromatolites.
12OutgassingThe process by which volcanoes vent water vapor, carbon dioxide, nitrogen, and other substances is called outgassing.
13PhotosynthesisCyanobacteria use the process of photosynthesis to produce energy, and oxygen is given off as a waste product.
14Banded iron formationThese are deposits consisting of alternating bands of chert and iron oxide.
15Red bedsSedimentary rocks younger than 1.8 billion years that are colored by the iron oxides in them.
16Start 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.
17Miller and UreyMiller and Urey demonstrated that the basic building blocks of life were most likely present on Earth during the Archean.
18Miller and Urey (continued) Heat, cyanide, and certain clay minerals can cause amino acids to join together in chains.
19Prokaryote.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.
20Prokaryote vs. Eukaryote A 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.
21ExtinctionsA major extinction of acritarchs occurred near the end of the Proterozoic, in which widespread glaciations may have played a critical role.
22Objectives Slides 23-38Describe the paleogeography of Laurentia. Discuss the concept of a passive margin. Describe the Cambrian fauna. Describe the Middle Paleozoic paleogeography. Explain the concept of an active margin and the formation of a clastic wedge.Describe the Middle Paleozoic fauna. Define the concept of mass extinction. Describe the formation of Pangaea. Explain how cyclotherms formed. Identify the importance of amniote eggs. Discuss the causes of the Late Permian mass extinction.
23Ancient geographic setting of an area. PaleogeographyAncient geographic setting of an area.
24LaurentiaDuring the Cambrian, Laurentia was covered by a sea.
25Laurentia - Precambrian On 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.
26Passive MarginWhen there is no tectonic activity along the edge of a continent, the edge is referred to as a passive margin.
27Cambrian explosionDuring the Cambrian explosion, all but one of the major marine phyla appeared.
28Cambrian explosion (continued) The Cambrian explosion was marked by great diversity of life, including the development of animals with skeletons.
29Burgess ShaleBurgess Shale - Contains fossils of soft-bodied Cambrian organisms
30Evidence of past lagoons Fragile organisms can live in a lagoon, which is the calm area behind a reef.
31ReefsAn organic reef is a structure composed of carbonate skeletons made by living organisms, such as coral.
32Taconic OrogenyTaconic Orogeny - Mountain-building event named for the mountains of eastern New York State
33Clastic Wedge OriginsA triangular-shaped deposit composed of sediment eroded from adjacent mountains is called a clastic wedge.
34The following provides evidence of the Taconic Orogeny: angular unconformitiesclastic wedgesigneous intrusions
35Vascular PlantsThe ability to transfer water through stems and stalks characterizes vascular plants.
36Ancestral RockiesMountain range in present-day Colorado formed by inland uplift.
37Mountain BuildingThe Late Paleozoic was a time of active mountain building.
38CyclothemsThe series of transgressions and regressions that produce cyclothems were likely produced by glaciations.
39Objectives Slides 40-59Explain the breakup of Pangaea. Distinguish between the different characteristics of Mesozoic Orogenies. Describe how paleontologists distinguish among reptile, dinosaur and mammal fossils. Describe the type of tectonism that characterized the Cenozoic orogeny.Understand the extent of glaciation that occurred in N.A.. Discuss the changes in animals in N.A. during the Cenozoic. Identify the characteristics of primates. Explain what separates hominids from the other hominoids.
40200 MYAAs North America rifted from Europe and Africa, a continuous rift system called the Mid-Atlantic ridge was formed.
41New OceansAs Pangaea split apart, the rifts flooded to form new oceans.
42Pangaea break-upPangaea probably broke apart because it held heat beneath it, which caused the continent to expand and then fracture and break apart.
43Mesozoic orogeniesAs a result of the earliest of the Mesozoic orogenies in North America, large bodies of granite called batholiths exist throughout the Cordillera.
44Mesozoic orogenies (continued) Orogenic events at the end of the Mesozoic uplifted massive blocks of crust to form the Rocky Mountains.
45First Angiosperms Angiosperms - Seed-bearing plants that have flowers Archaefructaceae
46PhytoplanktonTiny, ocean-dwelling organisms called phytoplankton made up the base of the food chain during the Mesozoic.
47Vertebrates and Invertebrates from among the modern fauna. Vertebrates: bony fishes, sharks, aquatic reptiles, and aquatic mammalsInvertebrates: crabs, lobsters, shrimps, sponges, sea urchins, modern corals, snails, and clams.
48Mesozoic ammonitesFossils of ammonites are often used as index fossils because these marine animals were widespread and abundant during the Mesozoic.
49Early MammalsEarly mammals with a single jawbone arose from mammal-like reptiles.
50SauropodThe largest land animals that ever lived were the quadrupedal, plant-eating sauropods.
51S.W. U.S. tectonismThe subduction of the East Pacific Rise coincides with pull-apart tectonism in the southwestern United States.
52Pliocene ice ageAs the Pliocene ice age began, great savannas became arid land and many savanna mammals became extinct.
53Pliocene 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.
54Pliocene 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.
55Pliocene 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.
56Eocene MammalsMost of the currently living groups of mammals had appeared by the Eocene.
57Primate TraitsPrimates - Mammal possessing specialized traits related to arboreal lifestyle
58Primate Traits (continued) Two important anatomical traits of all primates are an opposable thumb and forward-facing eyes.
59Homo sapiens - Modern human species Us (you & I)Homo sapiens - Modern human species