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Continental Drift (for UPSC CSE)
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This lesson deals with: 1.Introduction to Continental Drift (Alfred Wagner theory) and its postulates 2. 5 stages of continental drift 3. Pangea 4. Evidences in favour of continental drift 5. Criticism of theory of continental drift This lesson will be extremely beneficial to those who are preparing for UPSC Civil Services Examination CSE (for IAS, IPS, IRS etc.), State Civil Services Examination (conducted by RPSC, UPPSC, MPPSC and so on), other examination conducted by UPSC and other government bodies which includes questions on General Knowledge, Current affairs, general awareness, General studies. It will also cover other related exams like Central Police Forces Exam (Assistant Commandant), SSC (Staff Selection Commission- Combined Graduate Level exams), Bank PO exams like IBPS, SBI and RBI exams, Combined Defence Service exam (CDS), ACIO (Assistant Central Intelligence Officer) etc. This lesson will also be beneficial to those who want to improve their general knowledge.

Bhumika Saini
B Tech from MNIT, Jaipur. Appeared in CSE interview thrice. Loves teaching and playing badminton.

Unacademy user
thanx for the class sir
true and legendary way to make other understands basic ...hats off to you ma'am please continue your. valuable efforts .
hello ma'am.. ma'am if your optional subject is please make a list of books needed for geography optional thankyou
hello ma'am.. ma'am if your optional subject is please make a list of books needed for geography optional thankyou
Maybe the westward drift can be explained by newtons 1st law....the mass remain at rest while the earth rotates towards east giving a notion that the landmass drifted towards west..
mam, how the point of sial floating over sima is wrong? Plz help.
Pragya Raj
a year ago
it is right that sial is floating over sima...btt what is wrong is that Alfred wegener said that sial is floating over sima without any friction or any resistance and later on it proved wrong as said in the video that if there is no friction then how there is the formation of Rockies Nd Andes tooks place.
  1. Plate tectonics Bhumika Saini

  2. Prelude to plate tectonics . Continental drift .Sea floor Spreading Geomagnetism Plate tectonics theory

  3. Continental drift Wegner wrote book Origin of continent and oceans in 1912 . Wegner wrote book .Premises A supercontinent existed Pangea near present Durbar Pangea surrounded by Panthalasa SIAL is floating over SIMA e Pangea surrounde . Northern part called laurentia and southern part gondwanaland . Pangea divded by a shallow and meandering water body - Tethys sea

  4. Stages . Pangea stage (during carboniferous period) STAGE 1 Flight of continents(continents began to drift and break in Stage 2 pieces-Laurentia and gondwana) . Opening of tethys (The intervening space between laurentia and gondwana got filled with tethys sea and it widened) Stage 3 . Westward Drift( North and South america drifted westwards Stage 4 and altantic ocean opened) . Orogenetic Stage(Rockies and Andes formed) Stage 5

  5. PANGAEA the large landmass that included all of Earth's present day continents LAURASIA Esastor SEA a. PERMIAN 225 million years ago TRIASSIC 200 million years ago JURASSIC 135 million years ago Equitor CRETACEOUS 65 million years ago PRESENT DAY

  6. Forces Northward shift . Difference between force of buyoncy and graviational pull Tidal force of moon Westward shift

  7. Evidences Continental Drift Theory Evidence for Continental Drift includes includes includes includes ntinenta Edges Rock Structures Same Fossils Climate fit like showed seen in evidence from found Mountains with similar features Puzzle Pieces On different continents Continental ice sheets

  8. 1. SHAPE OF THE CONTINENTS Continentft together lke puzzle pieces Madagascar AFRICA Sri Lanka INDIA SOUTH AMERICA AUSTRALIA ANTARCTICA Map O2007 Richard W. Hughes

  9. 2. FOSSIL EVIDENCE SAME FOSSILS: DIFFERENT CONTINENTS Lystrosaurus Africa AFRICA INDIA South America USTRALI SOUTH AMERICA ANTARTICA Cynognathus Glossopteris Mesosaurus Mesosaurus was incapable of swimming across a large ocean.

  10. Geological Evidence SAME ROCK: DIFFERENT RANGE Existing mountain ranges separated by vast oceans contain rocks of identical mineral content. -A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles. edonian Hercyn ercynian Front Triassic Cape Foldings

  11. Criticism Forces -not sufficient to drift the continents Precarboniferous history not known Why only northward and westward drift Sial floating over Sima - in reality lithosphere is floating on aesthenosphere . Formation of mountains(rockies and Andes) due to friction by Sima is self contadictory Did not explain the formation of oceanic ridges and Island arcs