I. Fragmentation of the Gondwana super-continent Creation of new Oceans Atlantic Indian
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Transcript of I. Fragmentation of the Gondwana super-continent Creation of new Oceans Atlantic Indian
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
Major tectonic systems operating during the past 200 My
# 18 42.7 MaMiddle Eocene
Drake Passage Indian Pacific connection
#13 35.5 MaEarly Oligocene
Drake Passage Indian Pacific connection
#6, 20.5 MaEarly Miocene
Drake Passage Indian Pacific connection
Drake Passage Indian Pacific connection
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
thinned continental crust
Sedimentation on subsiding continental shelf
oceanic crust
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
Major tectonic systems operating during the past 200 My
Complex intra-continental Mediterranean-central Asian
“plate boundary”
Indonesian (Sunda-Banda) island arc
Earthquake depth 0-33 km 33-70 70-300 300-700
Topography for previous slide: note complex topography of Mediterranean-central Asian “plate boundary”.
India moving northwards
Himalayan evolution
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 MaBanggong,160 MaJinsha, 200 MaKunlun, 255 MaTienshan, late Paleozoic
The indentation has moved these sutures northwards
The dotted areas show the regions of shearing that accomodated the northward indentation of India
Tibetan plateau models
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.
Central Asian active
tectonics
II. Pacific System East Pacific Rise (EPR) moving towards the Americas and away from Asia Hot spot tracksRimmed 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
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II. Pacific System East Pacific Rise (EPR) moving towards the Americas and away from Asia Hot spot tracksRimmed 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
Northwestern Pacific Subduction zones: seismicity
Izu-Bonin-Marianas island arc
Aleutian Island arc
Ryukyu island arc
Kurile-Kamchatka island arc
N. Honshu subduction zone
Earthquake depth 0-33 km 33-70 70-300 300-700
Northwestern Pacific Subduction zones: bathymetry
New Zealand
New Britain Island arc
Vanuatu island arc Tonga
island arc
Kermadec island arc
Southwestern Pacific Subduction zones:
seismicity
Earthquake depth 0-33 km 33-70 70-300 300-700
Southwestern Pacific Subduction zones:
bathymetry
II. Pacific System East Pacific Rise (EPR) moving towards the Americas and away from Asia Hot spot tracksRimmed 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 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
Hot spot tracks
Major tectonic systems operating during the past 200 My
Eastern Pacific
Nazca Plate8 cm/yr
South American Plate
South America Plate
Central Andes cross section
II. Pacific System East Pacific Rise (EPR) moving towards the Americas and away from Asia Rimmed by subduction zones
• Western Pacific• Subducting old oceanic lithosphere• Formation of back-arc basins and island arcs
• Hot spot tracks•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
Continued in western_usa.ppt