TY - JOUR
T1 - Magmatism of the Shuteen Complex and Carboniferous subduction of the Gurvansaikhan terrane, South Mongolia
AU - Batkhishig, Bayaraa
AU - Noriyoshi, Tsuchiya
AU - Greg, Bignall
N1 - Funding Information:
This paper was prepared while BB was at the University of Mainz, Germany. The first author would like to thank Professor Alfred Kroener and Dr. Reimar Seltmann for their kind support and assistance, and would like to acknowledge the support of a German Research Council (DFG) Grant ( KR590/91-1 ). We sincerely thank the reviewers for their helpful and constructive comments that led to improvements in the manuscript.
PY - 2010/3/25
Y1 - 2010/3/25
N2 - The Carboniferous Shuteen Complex, a volcano-plutonic ring complex associated with Cu-Au porphyry mineralization, is located in the Gurvansaikhan island arc terrane of South Mongolia. This paper presents new data on the petrography, major and trace element chemistry, and Sr-Nd isotopic chemistry of the Shuteen Complex. We discuss the relationship between volcanic and plutonic rocks of the complex, and consider their similarity to high-Al2O3 trondhjemite-tonalite-granodiorite and adakites. We also consider the origin, magma source, and dynamic processes of the Shuteen Complex; propose a petrogenetic model; and investigate the composition of the subducting slab and the features of arc volcanism at the time. We assess some of the magmatic processes likely to have occurred within the Shuteen Complex, such as Carboniferous slab subduction and partial melting, and examine their influence on magma composition. The Shuteen Complex is geochemically similar to adakite-type rocks. The complex is silica-saturated (SiO2 ≥ 56%), rich in Al2O3 (≥15%), MgO (<6%), Y (≤18 ppm), and Yb (≤1.9 ppm), depleted in heavy rare earth elements, rich in Sr (>400 ppm), and depleted in high field strength elements. It also has a high Sr/Y value, and (87Sr/86Sr)I < 0.7040. The Shuteen Pluton yields a well-defined isochron age of 321 ± 9 Ma, whereas the age of the Shuteen andesites is 336 ± 24 Ma. The Shuteen Complex formed within an island arc setting, and partial melting was the dominant process during petrogenesis. The primary Shuteen magma had an adakitic composition and was probably derived from the partial melting of subducting oceanic crust, possibly with minor local interaction with mantle material. The results of quantitative modelling of mass balance and partial melt equilibrium for the magma source indicate that the subducting slab contained oceanic basalt and a minor component of oceanic sediment, which together with a restite eclogite phase formed the source of the Shuteen magma. The conclusive results of this study provide new insights into the magmatic evolution of the Shuteen Complex.
AB - The Carboniferous Shuteen Complex, a volcano-plutonic ring complex associated with Cu-Au porphyry mineralization, is located in the Gurvansaikhan island arc terrane of South Mongolia. This paper presents new data on the petrography, major and trace element chemistry, and Sr-Nd isotopic chemistry of the Shuteen Complex. We discuss the relationship between volcanic and plutonic rocks of the complex, and consider their similarity to high-Al2O3 trondhjemite-tonalite-granodiorite and adakites. We also consider the origin, magma source, and dynamic processes of the Shuteen Complex; propose a petrogenetic model; and investigate the composition of the subducting slab and the features of arc volcanism at the time. We assess some of the magmatic processes likely to have occurred within the Shuteen Complex, such as Carboniferous slab subduction and partial melting, and examine their influence on magma composition. The Shuteen Complex is geochemically similar to adakite-type rocks. The complex is silica-saturated (SiO2 ≥ 56%), rich in Al2O3 (≥15%), MgO (<6%), Y (≤18 ppm), and Yb (≤1.9 ppm), depleted in heavy rare earth elements, rich in Sr (>400 ppm), and depleted in high field strength elements. It also has a high Sr/Y value, and (87Sr/86Sr)I < 0.7040. The Shuteen Pluton yields a well-defined isochron age of 321 ± 9 Ma, whereas the age of the Shuteen andesites is 336 ± 24 Ma. The Shuteen Complex formed within an island arc setting, and partial melting was the dominant process during petrogenesis. The primary Shuteen magma had an adakitic composition and was probably derived from the partial melting of subducting oceanic crust, possibly with minor local interaction with mantle material. The results of quantitative modelling of mass balance and partial melt equilibrium for the magma source indicate that the subducting slab contained oceanic basalt and a minor component of oceanic sediment, which together with a restite eclogite phase formed the source of the Shuteen magma. The conclusive results of this study provide new insights into the magmatic evolution of the Shuteen Complex.
KW - Adakite
KW - Partial melting
KW - Shuteen
KW - South Mongolia
KW - Subduction
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U2 - 10.1016/j.jseaes.2009.10.004
DO - 10.1016/j.jseaes.2009.10.004
M3 - Article
AN - SCOPUS:74849116325
VL - 37
SP - 399
EP - 411
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
SN - 1367-9120
IS - 5-6
ER -