Plate-Tectonics.pdf

Plate Tectonics  Learning Goals: 1. Describe the differences of Earth million years ago and the present. 2. Enumerate the lines of evidence that supports plate movement. 3. Describe how does Earth exhibit evolution. 4. Reflect on how amazing God is for making the world a better place t...

Plate Tectonics  Learning Goals: 1. Describe the differences of Earth million years ago and the present. 2. Enumerate the lines of evidence that supports plate movement. 3. Describe how does Earth exhibit evolution. 4. Reflect on how amazing God is for making the world a better place to live in.  Vocabulary 1. Pangaea- a supercontinent which existed 225 million years ago that incorporated all the landmasses of Earth. 2. Plate Tectonics- scientific theory that describes the motion of the seven plates of Earth lithosphere. Think! How was Earth then compared to now? Picture Analysis: Which map best represents Earth? Earth may appear as solid, steady, and unchaging sphere of rock but in truth, it is constantly undergoing minor or major changes externally and internally. Several theories have been proposed to explain changes such as the formation of different landforms, separation of continents, formation of new ocean floor, and movements of lithospheric plates. Earth began as a single landmass or supercontinent called Pangaea. The term PANGAEA comes from the Greek words span which means “all” and gaea which means “Earth” Pangaea literally translates to “all of Earth” or “all lands”. It was surrounded by a vast sea or superocean called Panthalassa, which mean “all seas” It has been proposed that today’s continents were once joined were once joined together and gradually drifted apart as a results of tectonic forces. These continents are cradled by continental tectonic plates found on the lithosphere.  Present-day continents were once joined together as one supercontinent.  How does Earth exhibit evolution? How was Earth then compared to now?  Theories about Tectonic Plate Movements 1. Contraction Theory 2. Theory of Continental Drift 3. Seafloor Spreading Theory 4. Theory of Plate Tectonic  Theories about Tectonic Plate Movements  Learning Goals: 1. Explain what is plate tectonic theory. 2. Enumerate the lines of evidence that supports plate movement. 3. Describe how does Earth exhibit evolution. 4. Reflect on how amazing God is for making the world a better place to live in.  Theories about Tectonic Plate Movements 1. Contraction Theory 2. Theory of Continental Drift 3. Seafloor Spreading Theory 4. Theory of Plate Tectonic  - Early 20th century - Earth cooled after its formation, its surface contracted and Contraction Theory wrinkled, with these wrinkles being the mountain ranges on Earth’s surface.  - Furthermore, the theory also assumed that all other features on Earth were formed Contraction Theory during single cooling event and that the planet was relatively static.  - Without any significant changes since the Contraction Theory cooling (and wrinkling) slowed to a halt.  - Proposed by Alfred Wegener in1912. Theory of - Once there exist a Continental Drift single large landmass or supercontinent called PANGAEA.  - Wegener’s theory was Theory of based upon his Continental Drift observation which included the following:  - 1. The apparent fit of the eastern Theory of coastline of South Continental Drift America and western coastline of Africa.  - 2. Similarities of plant and animal fossils in South Theory of America and some Continental Drift parts of the African continent, which were separated by a vast ocean.  - 3. Similarities in the sequence of rock Theory of layers of opposite Continental Drift sides of the Atlantic Ocean.  - Pangaea would later break into two Theory of smaller Continental Drift supercontinents called: GONDWANA and LAURASIA.  - Pangaea would later break into two Theory of smaller Continental Drift supercontinents called: GONDWANA and LAURASIA.  - These two supercontinents Theory of further spilt into Continental Drift smaller landmasses, which are continents today.  - Gondwana is composed of Africa, Antarctica, South America, Australia, Theory of and the subcontinent Continental Drift of India. - Hypothesized by Eduard Suess in mid 1800  - Laurasia was a precursor of Asia, North America, and Theory of Europe. Continental Drift - Coined by South African geologist Alexander du Toit in 1937.  - The theory of continental drift was rejected because Wegener failed to Theory of provide compelling Continental Drift evidence for the mechanisms that drives the movement of plates.  - About half a century after his death, advancement in Theory of science enabled Continental Drift further studies and new ways to study tectonic movements.  - His theory would be improved upon, Theory of cementing his legacy Continental Drift as one of the pioneers of plate tectonics.  - States that the seafloors or ocean Seafloor Spreading floors – not the Theory continents- move and carry the continents along.  - Incorporates the Theory of Plate continental drift theory Tectonics and the seafloor spreading theory.  - Plate tectonics explains that Earth’s lithosphere is Theory of Plate composed of many Tectonics independent massive slabs of solid rocks called PLATES.  - Plates floats on an inner pliable mantle. Theory of Plate This movement is Tectonics due to the convection currents beneath the plates.  - The heat driving the convection currents Theory of Plate is the radioactive Tectonics decay underneath Earth.  - With the discovery of spreading oceans as explained by the Theory of Plate seafloor spreading Tectonics theory, the ocean floor is continually moving.  - There are 15 major tectonic plates that consist of 7 primary At PRESENT…. plates and 8 secondary smaller plates.  - Eurasian Plate - Australian Plates - Pacific Plate - North American Plate Primary Plates - South American Plate - African Plate - Antarctic Plate  - Juan de Fuca Plate - Nazca Plate - Cocos Plate - Caribbean Plate Secondary Plates - Philippine Sea Plate - Arabian Plate - Indian Plate - Scotia Plate  Is it possible that the continents would converge into a single landmass or supercontinent after 250 million years?  Christopher Scotese- predicts that the continents will r eform into a supercontinent. He called this supercontinent PANGAEA ULTIMA, meaning “Last Pangaea” but later decided to change it to PANGAEA PROXIMA “Next Pangaea”. He believes that the cycle of a supercontinent splitting into small continents and recombining as a single landmass will continue in the next billion years.  What are oceanic plates? Continental plates?  Answer: Oceanic plates are plates under the oceans such as Pacific plate and Nazca plate, while continental plates are plates under landmasses such Eurasian plate and Arabian plate. Questions? Thank You!