1 PPT CUHP [Compatibility Mode]the continentaldrift theory based upon wegeners concept.pdf

The ppt decribes the basic to advance level the theory of Webners continental drift. That is relevant for the sake of school level exams to upsc competitive level. The theory is completely comprising of the most crisp details that are required to study the interior of earth. The theory is relevant for studying the continental frift and sea floor spreading.Here is a 500-word paragraph on continental drift and sea floor spreading:

Continental drift and sea floor spreading are two fundamental concepts in the theory of plate tectonics, which revolutionized our understanding of Earth's dynamic surface. The idea of continental drift, proposed by Alfred Wegener in 1912, suggests that the continents have moved over time and were once joined together in a single supercontinent, Pangaea. Wegener observed the fit of the continents, matching coastlines, and similar fossil records across different continents. However, his hypothesis lacked a mechanistic explanation. Later, in the 1960s, the discovery of mid-ocean ridges and the mapping of oceanic crust revealed the process of sea floor spreading. This process involves the creation of new oceanic crust at mid-ocean ridges, where magma rises from the Earth's mantle and solidifies, pushing older crust apart. As the new crust is created, the older crust is forced apart, carrying the continents with it. This process is driven by convection currents in the Earth's mantle, which slowly move the tectonic plates. The combination of continental drift and sea floor spreading explains the movement of continents, the creation of oceanic crust, and the formation of mountain ranges, volcanoes, and earthquakes. The theory of plate tectonics has had a profound impact on our understanding of Earth's history, enabling us to better understand geological processes and predict natural hazards.Here is an additional 500 words on continental drift and sea floor spreading:

The evidence for continental drift and sea floor spreading is extensive and comes from various fields of study. One key piece of evidence is the fit of the continents, which Wegener originally observed. The eastern coast of South America and the western coast of Africa, for example, have a similar shape and fit together like a puzzle piece. Additionally, the same fossil species have been found on different continents, indicating that these areas were once connected. The presence of similar rock formations and mountain ranges on different continents also supports the idea of continental drift.

The discovery of mid-ocean ridges in the 1950s and 1960s provided further evidence for sea floor spreading. These underwater mountain ranges are formed by plate tectonic activity, where new oceanic crust is created as magma rises from the Earth's mantle and solidifies. The rocks on either side of the ridge are progressively older, indicating that the crust is being pushed apart as new crust is formed. This process is accompanied by volcanic activity and the creation of ocean

1. Introduction
continentaldrifttheoryestablishedbyAlfredwegenerin1912whichisrelatedtooriginand
distributionofcontinentandoceanbodies.LongagotherewasasupercontinentcalledPangaea.
PangaeaisNorthAmerica,SouthAmerica,Europe,Asia,Africa,Australia,Antarctica,andIndiaput
together.AlfredWagenerdiscoveredthistheory.Hebelievedallcontinentswereonceconnected.
Hisevidencewastrue.Ofcourseitsplitandhisevidenceonhowitsplitwasnottrue,buthewason
therighttrack.Thisiswhathappened.Around250millionyearsago,Pangaeabegantosplitapart
formingtwosmallercontinents,LaurasiaandGondwanaland.LaurasiawastheNorthern
HemisphereandGonwanalandwastheSouthernHemisphere.Around130millionyearsago,
GonwanalandandLaurasiabegantosplitintomorecontinentsandtheystillcontinueseparating
eventoday.(http://www.bookrags.com)
TherearemanythingsthatsupportContinentalDrift.TheyarefossilsthatarefromMesosaurusand
Lystrosaurus.Thesamedinosaurfossil,Mesosaurus,onBrazilwasalsofoundinAfrica.Those
animalscouldn'tswimfardistancessotheycouldnotgofromcontinenttocontinent.Thereforethey
wereonceconnected.Thereisalsoclimatethatsupportscontinentaldrift.Climateoftheisland
Spitsbergen,whichliesontheArticOceanNorthofNorway,iscoveredwithice,butfossilsof
tropicalplantswerefoundthere.Landformsalsohelpsupportthistheorybecauseifyoulookatthe
shapeoftheworldyoucanseeitkindoffitstogetherasapuzzle.(http://www.bookrags.com)

2. Basic Concept
Pangaeawasasupercontinentthatexistedduringthelate
PaleozoicandearlyMesozoiceras.Itassembledfromearlier
continentalunitsapproximately335millionyearsago,andit
begantobreakapartabout175millionyearsago.Incontrastto
thepresentEarthanditsdistributionofcontinentalmass,much
ofPangaeawasinthesouthernhemisphereandsurroundedbya
superocean,Panthalassa.Pangaeawasthemostrecent
supercontinenttohaveexistedandthefirsttobereconstructed
bygeologists.
Panthalassa Panthalassa,also known as the Panthalassicor Panthalassan
Ocean, was the superoceanthat surrounded the supercontinent Pangaea. During the Paleozoic-Mesozoic transition it
occupied almost 70% of Earth's surface. Its ocean floor has been completely disappeared because of its continental
margins on its circumference. Panthalassa is also referred to as the Paleo-Pacific ("Old Pacific") or Proto-Pacific
because the Pacific Ocean developed from its centerin the Mesozoic to the present. When Panthalassa surrounded
Pangaea Laurasia was located in the northern Hemisphere and Gondwanain the southern. Outline of present-day
land masses added for orientation.
MapofPangaeaandPanthalassain
mesozoicera(withmoderncontinental
outlines)

3. Earth Surface
PANGAEA Laurasia
North America
continent
Euro Asia
Continent
Greenland and other
major Island
Godawana
South America
continent
Africa continent
Australia continent
Antarctica continent
PANTHALASSA
Atlantic Ocean
Indian ocean
Pacific Ocean
(Pacific Ocean Money is The
Residual Part of Panthalassa)
Arctic Ocean
Force Responsible
of Continental Drift
Gravitational Force of Earth Pole
Tidal force of Sun and Moon
Buoyancy Force

4. Various Phases ofContinental Drift
Earth Today
Source: Encyclopaedia Britannica-2012, & Author
Panthalassa Panthalassa
Panthalassa

5. Continental structural
evidence
Continental fossils
evidence
Locations of Past
Glaciations
Source: http://geologylearn.blogspot.in/2016/02/ wegeners-evidence-for-continental-drift
Wegener’s Evidence for Continental Drift

6. The Distribution of Fossils:
Today,differentcontinentsprovidehomesfordifferentspecies.Kangaroos,for
example,liveonlyinAustraliaSimilarly,manytypesofplantsgrowonlyononecontinentandnotonothers.Why?
Becauseland-dwellingspeciesofanimalsandplantscannotswimacrossvastoceans,andthusevolvedindependentlyon
differentcontinents.DuringaperiodofEarthhistory,however,landanimalsandplantscouldhavemigratedamongmany
continents.Withthisconceptinmind,Wegenerplottedfossiloccurrencesofland-dwellingspeciesthatexistedduringthe
latepaleozoicandearlyMesozoiceras(betweenabout300and210millionyearsago)andfoundthatthesespecies
actuallyexistedonseveralcontinents.Wegenerarguedthatthedistributionoffossilspeciesrequiredthecontinentsto
havebeenadjacenttooneanotherinthelatePaleozoicandearlyMesozoicEras.
(http://geologylearn.blogspot.in/2016/02/wegeners-evidence-for-continental-drift)
TheFitoftheContinents:AlmostassoonasmapsoftheAtlanticcoastlinesbecameavailableinthe1500s,
scholarsnoticedthefitofthecontinents.ThenorthwesterncoastofAfricacouldtuckinagainsttheeasterncoastofNorth
America,andthebulgeofeasternSouthAmericacouldnestlecozilyintotheindentationofsouthwesternAfrica.Australia,
Antarctica,andIndiacouldallconnecttothesoutheastofAfrica,whileGreenland,Europe,andAsiacouldpackagainstthe
northeasternmarginofNorthAmerica.Infact,allthecontinentscouldbejoined,withremarkablyfewoverlapsorgaps,to
createPangaea.Wegenerconcludedthatthefitwastoogoodtobecoincidenceandthusthatthecontinentsoncedidfit
together.(http://geologylearn.blogspot.in/2016/02/wegeners-evidence-for-continental-drift)
LocationsofPastGlaciations:Wegenerwasanarcticclimatescientistbytraining,soit'snosurprisethathehada
stronginterestinglaciers.Heknewthatglaciersformmostlyathighlatitudestoday.Sohesuspectedthatifheplotteda
mapofthelocationsoflatePaleozoicglacialtillandstriations,hemightgaininsightintothelocationsofthePaleozoic.
Whenheplottedtheseplaces,hefoundthattheglaciersofthistimeintervaloccurredinsouthernSouthAmerica,southern
Africa,southernIndia,Antarctica,andsouthernAustralia.Theseplacesarenowwidelyseparatedand,withtheexceptionof
Antarctica,donotcurrentlylieincoldpolarregions(figureabovea).ToWegener'samazement,alllatePaleozoicglaciated
areaslieadjacenttoeachotheronhismapofPangaea.Furthermore,whenheplottedtheorientationofglacialstriations,
theyallpointedoutwardfromalocationinsoutheasternAfrica.Inotherwords,Wegenerdeterminedthatthedistributionof
glaciationsattheendofthePaleozoicEracouldeasilybeexplainedifthecontinentshadbeenunitedinPangaea,withthe
southernpartofPangaeaahugeicecapcenter.Thisdistributionofglaciationcouldnotbeexplainedifthecontinentshad
alwaysbeenintheirpresentpositions.(http://geologylearn.blogspot.in/2016/02/wegeners-evidence-for-continental-drift)

7. R e f e r e n c e s
Singh,Savendra(2012):Geomorphology,PrayagPustakBhawanAllahabad.
Singh,Savendra(2007):PhysicalGeography,PrayagPustakBhawanAllahabad.
Sisodiya,M.S.(2009):Geography,UpkarPrakashanPrintingPressBypassRoadAgra.
Lovett,RichardA.(September5,2008)."SupercontinentPangaeaPushed,NotSucked,Into
Place".NationalGeographicNews.
Pangea".EncyclopædiaBritannicaInc.2015.
Rogers,J.J.W.;Santosh,M.(2004),ContinentsandSupercontinents,Oxford:OxfordUniversity
Press,p.146,ISBN0-19-516589-6.
https://en.wikipedia.org/wiki/Panthalassa.
encyclopediaBritannicaInc.
RejoinedContinents[ThisDynamicEarth,USGS]".USGS.
Wegener,A.(1966)[1929],TheOriginofContinentsandOceans,CourierDoverPublications,
ISBN0-486-61708-4
Source:http://geologylearn.blogspot.in/2016/02/wegeners-evidence-for-continental-drift.
http://geologylearn.blogspot.in/2016/02/wegeners-evidence-for-continental-drift.