10.6084/m9.figshare.3454523.v1
J.A. CHAMBERS
J.A.
CHAMBERS
T.W. ARGLES
T.W.
ARGLES
M.S.A. HORSTWOOD
M.S.A.
HORSTWOOD
N.B.W. HARRIS
N.B.W.
HARRIS
R.R. PARRISH
R.R.
PARRISH
T. AHMAD
T.
AHMAD
Tectonic implications of Palaeoproterozoic anatexis and Late Miocene metamorphism in the Lesser Himalayan Sequence, Sutlej
Valley, NW India
Geological Society of London
2016
Greater
Sutlej Valley
Jutogh Group
NW India Unravelling
Main Central Thrust
Lesser
Sequence
Geology
2016-06-21 12:10:52
Journal contribution
https://geolsoc.figshare.com/articles/journal_contribution/Tectonic_implications_of_Palaeoproterozoic_anatexis_and_Late_Miocene_metamorphism_in_the_Lesser_Himalayan_Sequence_Sutlej___Valley_NW_India/3454523
<p>Unravelling the kinematic evolution of orogenic belts requires that the defining tectonostratigraphic units, and structural
elements that bound them, are properly identified and characterized. In the Sutlej Valley (western Himalaya), the Munsiari
and Vaikrita thrusts have both been correlated with the Main Central Thrust. The sequence of amphibolite-grade rocks (the
Jutogh Group) bounded by these faults has been variously assigned to the Lesser Himalayan Sequence (based on provenance ages)
and to the Greater Himalayan Sequence (from its metamorphic grade). Trace-element and geochronological data from leucogranites
in the Jutogh Group (1) indicate crustal melting at <em>c</em>. 1810 Ma, before the deposition of the Greater Himalayan Sequence, thus correlating the Jutogh Group with the Lesser Himalayan
Sequence, and (2) record Proterozoic metamorphism overprinted at 10.5 ± 1.1 Ma (established from U–Pb analysis of uraninite)
during the Himalayan orogeny. Pressure–temperature–time data indicate that the Jutogh Group and Greater Himalayan Sequence
represent distinct tectonic units of the metamorphic core that were decoupled during their extrusion. This precludes extrusion
along a single, widening channel, and requires a southward shift of the locus of movement during the Late Miocene, coincident
with present-day precipitation patterns.
</p>