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

Eas

t Pac

ific

Ris

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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