scholarly journals Rutile in Amphibolite Facies Metamorphic Rocks: A Rare Example from the East Qinling Orogen, China

2021 ◽  
Vol 11 (18) ◽  
pp. 8756
Author(s):  
Changming Wang ◽  
Shicheng Rao ◽  
Kangxing Shi ◽  
Leon Bagas ◽  
Qi Chen ◽  
...  
Keyword(s):  
Thin Layers ◽  
Amphibolite Facies ◽  
Central China ◽  
Metamorphic Rocks ◽  
Qinling Orogen ◽  
Critical Metal ◽  
Icp Ms ◽  
North Qinling ◽  
Increasing Demand ◽  
Zr In Rutile

Rutile is an important ore mineral to meet the increasing demand of critical metal Ti in various sectors. Here we report a rare example of rutile deposits hosted within the Baishugang–Wujianfang amphibolite-facies metamorphic rocks in the East Qinling Orogen, central China. The rutiles are mostly located within or along the margins of biotite and show 94.6 to 99 wt% TiO2. Rutiles occur as chains, thin layers along the foliation, and dense clusters. The grains are coexisted with magnetite. Based on Zr-in-rutile thermometer the estimated crystallisation temperature is at 630 °C at 7.0 kba. Based on Cr/Nb ratio, the source of the rutile is correlated with Ti-bearing silicate minerals such as biotite from aluminous sedimentary protoliths. The rutile deposit formed during lower amphibolite-facies metamorphism, and is distinct from the eclogite- and granulite-related types elsewhere in the orogen. The LA-ICP-MS U–Pb analyses of rutiles from the deposit yield lower intercept 238U/206Pb ages of 386 ± 16 Ma at the Baishugang–Wujianfang district. These ages correspond to a Devonian arc–continent collisional event between the South and North Qinling domains in the East Qinling Orogen.

Geochronology of the transition of eclogite to amphibolite facies metamorphism in the North Qinling orogen of central China

Lithos ◽  
2011 ◽  
Vol 125 (3-4) ◽  
pp. 969-983 ◽  
Author(s):  
Hao Cheng ◽  
Chao Zhang ◽  
Jeffrey D. Vervoort ◽  
Xianhua Li ◽  
Qiuli Li ◽  
...  
Keyword(s):  
Amphibolite Facies ◽  
Central China ◽  
Qinling Orogen ◽  
The North ◽  
Facies Metamorphism ◽  
North Qinling

Early Paleozoic high-Mg granodiorite from the Erlangping unit, North Qinling orogen, central China: Partial melting of metasomatic mantle during the initial back-arc opening

Lithos ◽  
2017 ◽  
Vol 288-289 ◽  
pp. 282-294 ◽  
Author(s):  
Mohammed I.M. Abdallsamed ◽  
Yuan-Bao Wu ◽  
Wenxiang Zhang ◽  
Guangyan Zhou ◽  
Hao Wang ◽  
...  
Keyword(s):  
Partial Melting ◽  
Central China ◽  
Early Paleozoic ◽  
Qinling Orogen ◽  
North Qinling ◽  
Back Arc

scholarly journals Petrogenesis and Geochronology of Tianshui Granites from Western Qinling Orogen, Central China: Implications for Caledonian and Indosinian Orogenies on the Asian Plate

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 515
Author(s):  
Muhammad Saleem Mughal ◽  
Chengjun Zhang ◽  
Amjad Hussain ◽  
Hafiz Ur Rehman ◽  
Dingding Du ◽  
...  
Keyword(s):  
Partial Melting ◽  
Saturation Index ◽  
Central China ◽  
Qinling Orogen ◽  
North China Block ◽  
Western Qinling ◽  
The North ◽  
Western Segment ◽  
Indosinian Orogeny ◽  
North Qinling

The precise timing, petrogenesis, and geodynamic significance of three granitoid bodies (Beidao granite, Caochuanpu granite, Yuanlongzhen granite, and the Roche type rock) of the Tianshui area in the Western Qinling Orogen, central China, are poorly constrained. We performed an integrated study of petrology, geochemistry, and zircon U-Pb dating to constrain their genesis and tectonic implication. Petrographic investigation of the granites shows that the rocks are mainly monzogranites. The Al saturation index (A/CNK versus SiO2) of the granitoid samples indicates meta-aluminous to peraluminous I-type granites. Their magmas were likely generated by the partial melting of igneous protoliths during the syn-collisional tectonic regime. Rare-earth-elements data further support their origin from a magma that was formed by the partial melting of lower continental crust. The Beidao, Caochuanpu, and Yuanlongzhen granites yielded U-Pb zircon weighted mean ages of 417 ± 5 Ma, 216 ± 3 Ma, and 219 ± 3 Ma, respectively. This study shows that the Beidao granite possibly formed in syn- to post-collision tectonic settings due to the subduction of the Proto-Tethys under the North China Block, and can be linked to the generally reported Caledonian orogeny (440–400 Ma) in the western segment of the North Qinling belt, whereas Yuanlongzhen and Caochuanpu granites can be linked to the widely known Indosinian orogeny (255–210 Ma). These granitoids formed due to the subduction of the oceanic lithospheres of the Proto-Tethyan Qinling and Paleo-Tethyan Qinling. The Roche type rock, tourmaline-rich, was possibly formed from the hydrothermal fluids as indicated by the higher concentrations of boron leftover during the late-stages of magmatic crystallization of the granites.

scholarly journals Fluorluanshiweiite, KLiAl1.5□0.5(Si3.5Al0.5)O10F2, a New Mineral of the Mica Group from the Nanyangshan LCT Pegmatite Deposit, North Qinling Orogen, China

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 93
Author(s):  
Kai Qu ◽  
Xianzhang Sima ◽  
Guowu Li ◽  
Guang Fan ◽  
Ganfu Shen ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Central China ◽  
New Mineral ◽  
Qinling Orogen ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Mohs Hardness ◽  
North Qinling ◽  
Individual Grains ◽  
A Site

A new mineral species of the mica group, fluorluanshiweiite, ideally KLiAl1.5□0.5(Si3.5Al0.5)O10F2, has been found in the Nanyangshan LCT (Li, Cs, Ta) pegmatite deposit in North Qinling Orogen (NQO), central China. Fluorluanshiweiite can be regarded as the F-dominant analogue at the A site of luanshiweiite or the K-dominant analogue at the I site of voloshinite. It appears mostly in cookeite as a flaky residue, replaced by Cs-rich mica, or in the form of scale aggregates. Most individual grains are <1 mm in size, with the largest being ca. 1 cm, and the periphery is replaced by cookeite. No twinning is observed. The mineral is silvery white as a hand specimen, and in a thin section, it appears grayish-white to colorless, transparent with white streaks, with vitreous luster and pearliness on cleavage faces. It is flexible with micaceous fracture; the Mohs hardness is approximately 3; the cleavage is perfect on {001}; and no parting is observed. The measured and calculated densities are 2.94(3) and 2.898 g/cm3, respectively. Optically, fluorluanshiweiite is biaxial (–), with α = 1.554(1), β = 1.581(1), γ = 1.583(1) (white light), 2V(meas.) = 25° to 35°, 2V(calc.) = 30.05°. The calculated compatibility index based on the empirical formula is −0.014 (superior). An electron microprobe analysis yields the empirical formula calculated based on 10 O atoms and 2 additional anions of (K0.85Rb0.12Cs0.02Na0.03)Σ1.02[Li1.05Al1.44(□0.47Fe0.01Mn0.02)Σ0.5] Σ2.99(Si3.55Al0.45) Σ4O10F2, which can be simplified to KLiAl1.5□0.5(Si3.5Al0.5)O10F2. Fluorluanshiweiite is monoclinic with the space group C2/m and unit cell parameters a = 5.2030(5), b = 8.9894(6), c = 10.1253(9) Å, β = 100.68(1)°, and V = 465.37(7) Å3. The strongest eight lines in the X-ray diffraction data are [d in Å(I)(hkl)]: 8.427(25) (001), 4.519(57) (020), 4.121(25) (021), 3.628(61) (112), 3.350(60) (022), 3.091(46) (112), 2.586(100) (130), and 1.506(45) (312).

Geochemistry, petrogenesis and tectonic implications of granitic plutons at the Liziyuan orogenic goldfield in the Western Qinling Orogen, central China

2012 ◽  
Vol 150 (1) ◽  
pp. 50-71 ◽  
Author(s):  
TAO YANG ◽  
LAIMIN ZHU ◽  
FEI WANG ◽  
HUJUN GONG ◽  
RUKUI LU
Keyword(s):  
Gold Mineralization ◽  
Early Stage ◽  
Gold Deposits ◽  
Central China ◽  
Late Triassic ◽  
Trace Element Geochemistry ◽  
Qinling Orogen ◽  
Element Geochemistry ◽  
Medium Temperature ◽  
Icp Ms

AbstractThe Liziyuan goldfield is located along the northern margin of the western part of the Qinling Orogen (WQO). The goldfield consists of five gold-only deposits hosted by metavolcanic rocks, and one polymetallic (Au–Ag–Pb) deposit hosted by the Tianzishan Monzogranite. As the Liziyuan goldfield appears to be spatially and temporally related to the Jiancaowan Porphyry, the study of the deposit provides a crucial insight into the relationship between tectonic-magmatic events and gold metallogenesis in the WQO. In this paper, we present whole-rock major and trace element geochemistry, and in situ zircon U–Pb and Lu–Hf isotopic data from the Tianzishan Monzogranite and Jiancaowan Porphyry. The two granitic plutons are enriched in LILEs and LREEs, depleted in HFSEs and have zircon εHf(t) values between −14.1 and −5.1 for the Tianzishan Monzogranite and between −21.0 and −8.4 for the Jiancaowan Porphyry. These characteristics indicate that the granites are derived from the crust. The Tianzishan Monzogranite has LA-ICP-MS zircon U–Pb ages of 256.1 ± 3.7 to 260.0 ± 2.1 Ma, which suggests that it was emplaced in the WQO during the convergence of the North and South (Yangtze) China cratons in the early stage of the Qinling Orogeny. In contrast, the porphyry has a LA-ICP-MS zircon U–Pb age of 229.2 ± 1.2 Ma, which is younger than the peak collision age, but corresponds to the widespread Late Triassic post-collisional granitic plutons in the WQO. The Tianzishan Monzogranite has somewhat higher Sr contents (196–631 ppm), lower Y (2.23–19.6 ppm) and Yb (0.20–2.01 ppm) contents, and a positive Eu/Eu* averaging 1.15. These characteristics suggest the pluton was derived from partial melting of the thickened crust. In contrast, the relatively higher MgO content (0.85–2.08 wt%) and Mg no. (43.4–58.2) of the Jiancaowan Porphyry indicates that insignificant amounts of subcontinental lithospheric mantle-derived mafic melts were involved in the generation of the magma. The Liziyuan goldfield is hosted by faults in greenschist-facies metamorphic rocks. Fluid inclusion studies suggest that gold was precipitated from CO2-rich, low-salinity and medium temperature fluids. This feature is consistent with the other orogenic gold deposits throughout the world. The field relationships and zircon U–Pb ages of the two granitic plutons suggest that gold mineralization is coeval with or slightly younger than the emplacement of the Jiancaowan Porphyry. Therefore, both the porphyry and deposit formed during the post-collisional stage of the Qinling Orogen.

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