Geology and Lead‐Isotope Study of the Baiyinnuoer Zn‐Pb‐Ag Deposit, South Segment of the Da Hinggan Mountains, Northeastern China

Chen

et al. 2018

Geological Journal

The East Kunlun Orogen (EKO), as the west segment of the Central China Orogen, is the most important Triassic polymetallic metallogenic belt in China. In this paper, we summarize the geological characteristics (stratigraphy, structure, ore‐related plutons, wall rock alteration, and orebodies), ore‐forming fluids and materials, geochronology, and petro‐geochemistry of the representative porphyry–skarn Cu–polymetallic deposits, including the Saishitang, Hutouya, and Kaerqueka deposits in the EKO. The porphyry–skarn Cu deposits in the EKO are mainly distributed in tectonic units of the Qimantagh Belt and the Elashan Belt. Among them, the skarn Cu deposits provide the majority of Cu resources, which mainly occur in the contact zone between the Triassic granitoids and the volcanic–sedimentary rocks (e.g., the Ordovician–Silurian Tanjianshan Group and the Early to Middle Triassic Hongshuichuan Group), and the skarn and orebodies are mainly controlled by interlayer–gliding structures. Ore‐forming fluids of the porphyry Cu deposits are magmatic mixed with meteoric water, whereas the fluids of skarn Cu deposits are mainly of magmatic origin. The higher δ18O (>10‰) of garnet and pyroxene in prograde skarn and wide range of sulphur isotopic compositions (δ34S values from −8.9‰ to 11.0‰) suggest that ore‐forming materials of skarn Cu deposits were partially derived from the country rocks. Based on detailed field investigations, we identified four Cu mineralization types, including veinlet–disseminated Cu (Mo, Au) mineralization occurring within the intrusions, proximal skarn Cu (Fe, Pb, Zn, Au) mineralization, distal skarn Cu mineralization, and distal skarn Pb–Zn (Cu) mineralization. The porphyry–skarn Cu deposits are associated with magmatism that occurred mainly during 235–218 Ma. The ore‐related granitoids are mostly calc‐alkaline I‐type granites, derived from partial melting of the Precambrian basement rocks with various degrees of involvement of mantle components. Combined with the regional tectonic evolution, we conclude that the Cu mineralization in the EKO began with the closure of A'nyemaqen Ocean (~238 Ma) and subsequently culminated in a postcollisional setting (~225 Ma).

Section: Sources Of Sulphurmentioning

confidence: 99%

Geological characteristics, metallogenesis, and tectonic setting of porphyry–skarn Cu deposits in East Kunlun Orogen

Chen

et al. 2018

Geological Journal

“…As for other types of deposits, the majority of δ 18 O H2O values of main mineralization stage were between meteoric water and primary magmatic water, suggesting that the oreforming fluid could be mixed with significant meteoric water during its evolution. In addition, we also noted that the Early Cretaceous hydrothermal deposits in SGXR have very lower hydrogen isotope values, and the hydrogen isotope levels of some deposits are even lower than The data are from Feng et al, 1994;Chu and Huo, 2002;Liu et al, 2002;Niu et al, 2009;Zeng et al, 2009;Jiang et al, 2010;Zhou et al, 2011;Zhou et al, 2012;Ouyang, 2013;Ouyang et al, 2014;Li et al, 2015;Wang, 2017;Zhang, 2018).…”

Section: Sources Of Ore-forming Fluidsmentioning

confidence: 59%

“…Table 4 and Fig. 12b present the sulfur and lead isotopic compositions of ore minerals obtained from previous studies (Zeng et al, 2009;Shao et al, 2010;Zhou et al, 2012). The δ 34 S values of sulfide samples (galena and sphalerite) from the Haobugao deposit varied between −2.7‰ and −0.9‰, with a mean value of −1.6‰.…”

Section: Sulfur Isotopementioning

confidence: 89%

Geology, Mineralization, Fluid Inclusion and Stable Isotope of the Early Cretaceous Sn and Associated Metal Deposits in the Southern Great Xing'an Range, NE China: A Review

Acta Geologica Sinica (Eng)

Liu

Sun

et al. 2019

The Southern Great Xing'an Range (SGXR) hosts a number of Early Cretaceous Sn and associated metal deposits, which can be divided into three principal types according to their geological characteristics: skarn type deposits, porphyry type deposits and hydrothermal vein type deposits. Fluid inclusion assemblages of different types of deposits are quite different, which represent the complexities of metallogenic process and formation mechanism. CH4 and CO2 have been detected in fluid inclusions from some of deposits, indicating that the ore‐forming fluids are affected by materials of Permian strata. Hydrogen and oxygen isotope data from ore minerals and associated gangue minerals indicate that the initial ore fluids were dominated by magmatic waters, some of which had clearly exchanged oxygen with wall rocks during their passage through the strata. The narrow range for the δ34S values presumably reflects the corresponding uniformity of the ore forming fluids, and these δ34S values have been interpreted to reflect magmatic sources for the sulfur. The comparation between lead isotope ratios of ore minerals and different geological units’ also reveals that deeply seated magma has been a significant source of lead in the ores.

“…Geochronological data published for the Mo (Pb-Zn-Ag) mineralization in the southern part of the Great Xing'an Range [56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72]…”

Section: Ages Of Magmatism and Metallogenesismentioning

confidence: 99%

“…Geochronological data published for the Mo (Pb-Zn-Ag) mineralization in the southern part of the Great Xing'an Range [55,[58][59][60][61][62][63][64][65][66][67][68][69][70][71][72] are shown that this region records four stages for Mo (Pb-Zn-Ag) mineralization: (1) Late Permian (265 Ma), (2) Middle Triassic (244-235 Ma), (3) Middle-Late Jurassic (179-161 Ma), and (4) Late Jurassic-Early Cretaceous (147-132 Ma). The age of 162.6 ± 1.5 Ma obtained in this study is also consistent with the Middle-Late Jurassic stage of Mo-polymetallic mineralization in the southern part of the Great Xing'an Range, such as the Lianhuashan Cu + Ag + Mo deposit with a zircon U-Pb age of 161.8 Ma and the Shuangjianzishan deposit with a pyrite Re-Os isochron age of 165 ± 4 Ma, and slightly younger than the Meng'enTolgoi deposit, which had a muscovite Ar-Ar isochron age of 179 ± 2 Ma [58][59][60] (Figure 17).…”

Section: Ages Of Magmatism and Metallogenesismentioning

confidence: 99%

Geochronology of Magmatism and Mineralization in the Dongbulage Mo-Polymetallic Deposit, Northeast China: Implications for the Timing of Mineralization and Ore Genesis

Liu

et al. 2019

Minerals

The recently discovered Dongbulage Mo-polymetallic deposit is located in the southern part of the Great Xing'an Range, northeast China. Mineralization is closely related to the emplacement of Middle-Late Jurassic granitoids. In order to understand the petrogenetic link between mineralization and host granitoids, this study presents new zircon U-Pb ages, bulk-rock geochemistry, and molybdenite Re-Os ages for the Dongbulage deposits. LA-ICP-MS zircon U-Pb dating of the monzogranite and syenogranite intrusions yielded two weighted mean 206 Pb/ 238 U ages: of 164 ± 2 Ma and 165 ± 3 Ma, respectively. The subvolcanic rocks (red porphyritic granite and rhyolite) yielded a time interval between 161 ± 2 and 162 ± 3 Ma. In addition, molybdenite from the Dongbulage deposit gave a Re-Os isochron age of 162.6 ± 1.5 Ma, which was interpreted as the age of the mineralization. The new geochronology has established the close temporal and genetic relationships between the mineralization event and the emplacement of the Middle-Late Jurassic granitoids. Bulk-rock geochemistry shows that the Dongbulage granitoids are characterized by high SiO 2 , K 2 O, and A/CNK [Al 2 O 3 /(CaO + Na 2 O + K 2 O)(molar ratio)] values, and low TiO 2 , CaO, and MgO values, indicating a metaluminous to peraluminous, high-K calc-alkaline affinity. The granitoids also featured enrichments of large ion lithophile elements and light rare earth elements (LREE), and a relative depletion of high field strength elements (HFSE), along with an increasing negative δEu anomaly. The high differentiation index (DI), ranging from 81.75 to 94.76, and obvious fractionation between LREE and HREE, indicate that the Dongbulage granitoids are highly fractionated, metaluminous-peraluminous, and high-K calc-alkaline I-type granites. Combined with the regional geology, the Dongbulage granitoids may have formed during post-orogenic extension that followed the Mongol-Okhotsk Ocean closure coeval with subduction of the paleo-Pacific plate.Minerals 2019, 9, 255 2 of 34 source in China. This region is characterized by abundant highly evolved Mesozoic igneous rocks [2], and contains large-scale Ag-, Sn-, Mo-, and Cu-polymetallic vein deposits (Figure 1a) [3,4]. In this region, seven large base metal (≥0.5 Mt) and rare metal (≥0.2 Mt) deposits, and 25 smaller (0.1-0.5 Mt) base metal deposits have been discovered [5]. Three newly recognized metallogenic belts are located within the Great Xing'an Range and its adjacent areas. These are: the northern Mo ± Cu ore-forming belt; the middle Sn ± W ± Ag metallogenic belt; and the southern Mo ore-forming belt (Figure 1b) [6]. The recently discovered Dongbulage deposit is located where the northern Mo ± Cu and middle Sn ± W ± Ag mineralization belts come together (Figure 1b). The deposit represents an unusual example of Mo-polymetallic mineralization dominated by abundant Mo-Pb-Zn with minor Ag-Cu mineralization. The polymetallic features of the Dongbulage deposit represent a change in the style of mineralization characteristics between the Sn...