5.Tectonics CDT

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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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