5.tectonics cdt
DESCRIPTION
www.pmfias.com video PPT on geography. Visit www.pmfias.com for more.TRANSCRIPT
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Video Series on Geography (GS)
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Tectonics – Continental Drift Theory
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Geom
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Earth’s Interior
Earth Movements
Tectonics
Continental Drift
See Floor Spreading
Plate TectonicsTectonics and Orogeny
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Continental Drift Theory (CDT)
Convectional Current Theory
(CCT)
Sea Floor Spreading Theory
(SFST)
Plate Tectonics (PT)
Polar wandering (Similar to CDT)
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Important theories
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Polar Wandering
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Timeline
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Timeline
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Evidence in support of Continental Drift
Evidences for CDT
Apparent Affinity of Physical Features
Botanical Evidence
Placer Deposits
Tillite depositsPolar wandering
Distribution of Fossils
Rocks of Same Age Across the Oceans
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Apparent Affinity of Physical FeaturesTe
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Apparent Affinity of Physical FeaturesTe
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Apparent Affinity of Physical FeaturesTe
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The drift was in two directions
Equator-wards due to the
interaction of forces of
gravity, pole-fleeing force
and buoyancy, and
Westwards due to tidal
currents because of the
earth’s motion.
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Forces for the DriftTe
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Fossil and Botanical EvidencesTe
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Tillite DepositsTe
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Placer DepositsTe
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Wegener failed to explain why the drift began only in
Mesozoic era and not before.
The theory doesn’t take oceans into consideration.
Proofs heavily depend on assumptions and are very general
in nature.
Forces like buoyancy, tidal currents and gravity are too
weak to be able to move continents.
Modern theories (PT) accept the existence of Pangea and
related landmasses but give a very different explanation to
the causes of drift.
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Drawbacks of CDTTe
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Which of the following phenomena might have
influenced the evolution of organisms?
1. Continental drift
2. Glacial cycles
Select the correct answer using the code given below.
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
What do you understand by the theory of
continental drift? Discuss the prominent
evidences in its support.www.poormansfriend.org
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