@article{fdi:010090453,
  title = {{A}n embryonic fold and thrust belt south of the {H}imalayan morphological front : examples from the central {N}epal and {D}arjeeling piedmonts},
  author = {{M}ugnier, {J}.{L}. and {H}uyghe, {P}. and {L}arge, {E}. and {J}ouanne, {F}. and {G}uillier, {B}ertrand and {C}hakraborty, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he morphological boundary between the {H}imalayas and the foreland plain is well expressed and most often corresponds to the frontal emergence of the {M}ain {H}imalayan {T}hrust ({MHT}). {T}his boundary is affected by surface ruptures during very large {H}imalayan earthquakes ({M}w > 8) that regularly induce (with a recurrence of the order of 500 to 1200 years) the uplift of the foothills relative to the plain. {H}owever, a thrust-fold system is hidden beneath the plain and is displayed by the seismic profiles of oil companies in east/central {N}epal and by {H}/{V} passive geophysical techniques in {D}arjeeling. {I}ts long-term kinematic evolution is slow, with a tectonic uplift of the hanging wall that is lower than the subsidence rate of the foreland basin, that is, less than approximately half a millimetre per year. {D}uring phases of low sedimentation controlled by climatic fluctuations, the morphological surfaces of the piedmont are incised by large rivers for several tens of metres; therefore, structures hidden under the sediments emerge slightly in the plain. {T}he evolution of the hidden structures corresponds to an embryonic thrust belt mainly affected by a long-term shortening rate of 1.4 +2.5/ 1.2 mm-yr 1, that is, 2-20% of the shortening rate of the entire {H}imalayan thrust system. {N}onetheless, the details of the deformation associated with the embryonic thrust belt are still poorly understood. {S}everal deformation components could affect the central {H}imalayan and {D}arjeeling piedmonts. i) {A}ny slow steady-state deformation, such as layer parallel shortening ({LPS}) is not detected by {G}lobal {N}avigation {S}atellite {S}ystem ({GNSS}) data, and such deformation would therefore absorb less than 0.5 mm-yr 1. {T}he geodetic data that suggest the aseismic growth of some of the structures are highly controversial. ii) {F}or the rest of the deformation of the embryonic thrust wedge, it is yet to be proven whether deformation occurs during rare great earthquakes affecting the piedmont during medium earthquakes and/or during post-seismic deformation related to great earthquakes. {T}he amplitude of this long-term low deformation is too limited to significantly reduce the seismic hazard in the seismic gaps of the {H}imalayan belt. iii) {I}n some portions of the {H}imalayan front, such as {D}arjeeling ({I}ndia), the thrust deformation related to great earthquakes propagates several tens of kilometres south of the morphological front in the zone previously affected by the long-term low deformation. {I}t induces multi-metre surface ruptures in the piedmont and a mean shortening of 8.5 ± 6.2 mm-yr 1. iiii) {P}re-existing faults in the bedrock of the {I}ndian craton, often oblique to the {H}imalayan structures, are locally reactivated beneath the foreland plain with low deformation rates.},
  keywords = {{HIMALAYA} ; {INDE} ; {NEPAL} ; {DARJEELING} {PIEMONT} ; {GANGE} {PLAINE}},
  booktitle = {},
  journal = {{E}arth {S}cience {R}eviews},
  volume = {230},
  numero = {},
  pages = {104061 [25 ]},
  ISSN = {0012-8252},
  year = {2022},
  DOI = {10.1016/j.earscirev.2022.104061},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090453},
}