Page 326 - Global Tectonics

OROGENIC BELTS 309

(a) Permian-Triassic
rifting
Gond India Lhasa/Qiangtang Eurasia

(b) Late Triassic-Early Jurassic
rifting possible backarc
extension
Gond India Lhasa Qntg SG Eurasia

(c) Late Jurassic-Early Cretaceous
Collision and distributed shortening
BNS
Gond India Lhasa Qntg SG Eurasia

(d) Late Cretaceous
Shortening and some uplift
Gond India Lhasa Qntg SG Eurasia

(e) Early Cenozoic Collision
IZS
India Lhasa Qntg SG Eurasia

(f) Late Cenozoic continued convergence, uplift and deformation
India Lhasa Qntg SG Eurasia
ophiolite

Figure 10.15 Possible sequence of events in the evolution of the Himalayan–Tibetan orogen (modified from Haines

et al., 2003, by permission of the American Geophysical Union. Copyright © 2003 American Geophysical Union).
Interpretation incorporates relationships developed by Allègre et al. (1984) and Yin & Harrison (2000). BNS, Bangong–
Nujiang suture; SG, Songpan–Ganzi terrane; Gond, Gondwana; Qntg, Qiantang terrane; IZS, Indus–Zangbo suture.

ciated with a new plate boundary that is beginning to orogens (Section 10.6.2) and represents one of the most

form in the Indian Ocean (Van Orman et al., 1995). The efficient mechanisms of forming supercontinents
Indus–Zangbo suture now forms the southern bound- (Section 11.5). This history also resulted in a hot, weak
ary of the Tibetan Plateau (Fig. 10.13), which lies more Eurasia continental plate prior to its collision with India.
than 5000 m above mean sea level and covers an area of
more than a million square kilometers.
This history shows that the Himalayan–Tibetan 10.4.3 Surface velocity fields

orogen is built upon a collage of exotic material that
became welded to the Eurasian Plate before the main and seismicity
India–Eurasia collision (Sengör & Natal’in, 1996; Yin &
S
Harrison, 2000). This type of sequential amalgamation Since about 50 Ma, continued convergence between
of microcontinents and other material during pro- India and Eurasia at a slowed rate has caused India to
longed subduction is characteristic of accretionary penetrate some 2000 km into Asia (Dewey et al., 1989;