TY - JOUR
T1 - The role of pre-existing weak zones in the formation of the Himalaya and Tibetan plateau
T2 - 3-D thermomechanical modelling
AU - Chen, Lin
AU - Liu, Lijun
AU - Capitanio, Fabio A.
AU - Gerya, Taras V.
AU - Li, Yang
PY - 2020/6
Y1 - 2020/6
N2 - The Tibetan crust is sliced by several east–west trending suture zones. The role of these suture zones in the evolution of the Himalayan range and Tibetan plateau remains unclear. Here we use 3-D thermomechanical simulations to investigate the role of pre-existing weak zones within the Asian Plate in the formation of orogen and plateau growth during continental collision. Our results show that partitioning of deformation along the convergent margin leads to scraping off of crustal material into an orogenic wedge above the margin and crustal thickening in the retro-continent, eventually forming a large orogenic plateau in front of the indenter. Pre-existing weak zone(s) within the retro-continent is reactivated at the early stage of convergence, and facilitates the northward propagation of strain and widening of the orogenic plateau. The northernmost weak zone sets the northern limit of the Tibetan plateau. Our models also show rheological weakening of the congested buoyant crust within the collisional zone drives wedge-type exhumation of deeply buried crust at the southern flank of the plateau, which may explain the formation of the Greater Himalayan Sequence.
AB - The Tibetan crust is sliced by several east–west trending suture zones. The role of these suture zones in the evolution of the Himalayan range and Tibetan plateau remains unclear. Here we use 3-D thermomechanical simulations to investigate the role of pre-existing weak zones within the Asian Plate in the formation of orogen and plateau growth during continental collision. Our results show that partitioning of deformation along the convergent margin leads to scraping off of crustal material into an orogenic wedge above the margin and crustal thickening in the retro-continent, eventually forming a large orogenic plateau in front of the indenter. Pre-existing weak zone(s) within the retro-continent is reactivated at the early stage of convergence, and facilitates the northward propagation of strain and widening of the orogenic plateau. The northernmost weak zone sets the northern limit of the Tibetan plateau. Our models also show rheological weakening of the congested buoyant crust within the collisional zone drives wedge-type exhumation of deeply buried crust at the southern flank of the plateau, which may explain the formation of the Greater Himalayan Sequence.
KW - Asia
KW - Dynamics of lithosphere and mantle
KW - Landscape evolution
KW - Numerical modelling
KW - Tectonics
UR - http://www.scopus.com/inward/record.url?scp=85091479801&partnerID=8YFLogxK
U2 - 10.1093/GJI/GGAA125
DO - 10.1093/GJI/GGAA125
M3 - Article
AN - SCOPUS:85091479801
SN - 0956-540X
VL - 221
SP - 1971
EP - 1983
JO - Geophysical Journal International
JF - Geophysical Journal International
IS - 3
ER -