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Major tectonic systems. Dispersion of the Gondwana continents Closing of Tethys Ocean Pacific System: rimmed by subduction zones East Pacific Rise moving towards the Americas Western Pacific island arcs. Major tectonic systems operating during the past 200 My.
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Major tectonic systems • Dispersion of the Gondwana continents • Closing of Tethys Ocean • Pacific System: rimmed by subduction zones • East Pacific Rise moving towards the Americas • Western Pacific island arcs
Major tectonic systems operating during the past 200 My I. Fragmentation of the Gondwana super-continent • Creation of new Oceans • Atlantic • Indian • circum-Antarctic • formation of passive margins • Closing of Tethys Ocean: • complex Mediterranean – Middle East interactions • major continental collisions in central Asia • Australian-SE Asian collisions
# 18 42.7 Ma Middle Eocene Indian Pacific connection Drake Passage
#13 35.5 Ma Early Oligocene Indian Pacific connection Drake Passage
#6, 20.5 Ma Early Miocene Indian Pacific connection Drake Passage
Indian Pacific connection Drake Passage
Formation of Circum-Antarctic Current >> isolation of Antarctica >> formation of ice sheet circum-Antarctic Current
Formation of North Atlantic Deep water (thermo-haline convection system)
Formation of continental passive margins continental shelf
continental passive margins Sedimentation on subsiding continental shelf thinned continental crust oceanic crust
Major tectonic systems operating during the past 200 My I. Fragmentation of the Gondwana super-continent • Creation of new Oceans • Atlantic • Indian • circum-Antarctic • formation of passive margins • Closing of Tethys Ocean: • complex Mediterranean – Middle East interactions • major continental collisions in central Asia • Australian-SE Asian collisions
Earthquake depth 0-33 km 33-70 70-300 300-700 Complex intra-continental Mediterranean-central Asian “plate boundary” Indonesian (Sunda-Banda) island arc
Topography for previous slide: note complex topography of Mediterranean-central Asian “plate boundary”.
Indention of India into Asia The named dashed and dotted lines represent boundaries between terranes successively accreted to Asia. The accretion increases in age to the north: Indus Tsangbo, 40 Ma Banggong,160 Ma Jinsha, 200 Ma Kunlun, 255 Ma Tienshan, late Paleozoic The indentation has moved these sutures northwards The dotted areas show the regions of shearing that accomodated the northward indentation of India
Region of theTibetan Plateau Ignore white rectangle. The blue line shows the approximate location of the section shown in the third slide after this one.
A recently published geological cross section See the section line (blue line) on the map shown in the third preceding slide. From Yin, A. and T.M. Harrison, 2000, Geologic Evolution of the Himalayan-Tibetan Orogen, Ann. Rev. Earth Planet. Sci., v.28, 211-280.
Major tectonic systems operating during the past 200 My II. Pacific System • East Pacific Rise (EPR) moving towards the Americas and away from Asia • Hot spot tracks • Rimmed by subduction zones • Western Pacific • Subducting old oceanic lithosphere • Formation of back-arc basins and island arcs • Eastern Pacific • Subducting young oceanic lithosphere • Andean type mountain building • Collision and accretion of exotic terranes • Collision of EPR with North America
Major tectonic systems operating during the past 200 My II. Pacific System • East Pacific Rise (EPR) moving towards the Americas and away from Asia • Hot spot tracks • Rimmed by subduction zones • Western Pacific • Subducting old oceanic lithosphere • Formation of back-arc basins and island arcs • Eastern Pacific • Subducting young oceanic lithosphere • Andean type mountain building • Collision and accretion of exotic terranes • Collision of EPR with North America
Earthquake depth 0-33 km 33-70 70-300 300-700 Northwestern Pacific Subduction zones: seismicity Ryukyu island arc Kurile-Kamchatka island arc Aleutian Island arc N. Honshu subduction zone Izu-Bonin-Marianas island arc
Earthquake depth 0-33 km 33-70 70-300 300-700 New Britain Island arc Southwestern Pacific Subduction zones: seismicity Vanuatu island arc Tonga island arc Kermadec island arc New Zealand
Major tectonic systems operating during the past 200 My II. Pacific System • East Pacific Rise (EPR) moving towards the Americas and away from Asia • Hot spot tracks • Rimmed by subduction zones • Western Pacific • Subducting old oceanic lithosphere • Formation of back-arc basins and island arcs • Eastern Pacific • Subducting young oceanic lithosphere • Andean type mountain building • Collision and accretion of exotic terranes • Collision of EPR with North America