Syncollisional tholeiitic magmatism induced by asthenosphere upwelling owing to slab detachment at the southern margin of
the Central Asian Orogenic Belt
Xie-Yan Song
Lie-Meng Chen
Yu-Feng Deng
Wei Xie
10.6084/m9.figshare.3453449.v1
https://geolsoc.figshare.com/articles/dataset/Syncollisional_tholeiitic_magmatism_induced_by_asthenosphere_upwelling_owing_to_slab_detachment_at_the_southern_margin_of___the_Central_Asian_Orogenic_Belt/3453449
<p>The mafic–ultramafic complexes containing magmatic sulphides at the southern margins of the Central Asian Orogenic Belt have
been recently proposed to result from an Early Permian mantle plume. However, in this study we show that the plume model cannot
account for the observed geological characteristics of the Huangshan–Jingerquan mafic–ultramafic belt in the Northern Tianshan.
Low K<sub>2</sub>O contents and positive correlation between TiO<sub>2</sub> and (Fe<sub>2</sub>O<sub>3</sub>)<sub>T</sub>/MgO of the mafic–ultramafic complexes of this belt demonstrate a tholeiitic affinity. Enrichment of large ion lithophile
elements and depletion of high field strength elements (in particular Nb and Ta) relative to mid-ocean ridge basalt indicate
a subduction-modified mantle source. Lead isotope values and compositions of chromite indicate a significant contribution
from the melting of asthenosphere. The absence of Late Carboniferous strata in the Huangshan–Jingerquan belt and Early Permian
exhumation of blueschist and eclogite along the Aqikkuduk suture at the southern boundary of the belt indicate that an arc–continent
collision occurred in the Late Carboniferous to Early Permian. We propose that the detachment of oceanic lithosphere from
continental lithosphere during the collision induced asthenospheric upwelling, which resulted in melting of both the asthenosphere
and the overlying metasomatized mantle wedge, and the formation of the mafic–ultramafic complexes with ages of 270–285 Ma
along the Huangshan–Jingerquan belt.
</p>
2016-06-21 11:25:31
Lead isotope values
complex
Syncollisional tholeiitic magmatism
metasomatized mantle wedge
detachment
Orogenic Belt
Central
lithosphere
ion lithophile elements
upwelling
mafic
Carboniferou
Low K 2 O contents
asthenosphere
Fe 2 O 3
field strength elements
Huangshan
Permian mantle plume
Geology