Geology, geochemistry, and geochronology of the Cuihongshan Fe‐polymetallic deposit, Heilongjiang Province, NE China

Abstract

The Cuihongshan deposit is a giant Fe‐polymetallic skarn deposit located in the northern zone of the Lesser Xing'an–Zhangguangcai Range (LXZR), NE China. It is predominantly hosted in skarn contact zones between marble and alkali‐feldspar granites and monzogranites, with minor in fracture zones of granodiorites. Because of dense vegetation cover, complex intrusions, and contact relation between orebodies and rocks, the metallogenesis of the deposit is poorly understood. Here, we present detailed whole‐rock geochemistry, zircon U–Pb geochronology of granitoids, and molybdenite Re–Os isotopic dating data. All of the granitoids in the Cuihongshan deposit area are silica and potassium rich, highly fractionated, showing affinities to high‐fractionated I‐type granites. However, compared with the other granitoids, the Late Triassic alkali‐feldspar granites have higher differentiation index, stronger enrichment in F, W, Mo, Pb, Th, U, and volatiles with partial mineralization. The zircon U–Pb dating of the granodiorite, monzogranite, and alkali‐feldspar granite yielded weighted average ages of 493 ± 4, 194 ± 1, and 204 ± 1 Ma, respectively. The Re–Os dating of molybdenites from the Cuibei and Cuizhong ore sections yielded isochron ages of 205 ± 2 and 204 ± 4 Ma, respectively, which are consistent with the emplacement age of the alkali‐feldspar granite. Combined with the lines of evidence from the contact relationship between the orebodies and alkali‐feldspar granite, the disseminated mineralization and the enrichment in ore‐forming elements and volatiles in the alkali‐feldspar granite, these indicate that the Late Triassic alkali‐feldspar granite rather than the monzogranite as previously reported, has a close genetic relationship with the Cuihongshan deposit. In addition, the alkali‐feldspar granites occur as apophyses and dikes, but the Late Cambrian and Early Jurassic granitoids occur as batholiths. This indicates that, according to the theory that “small intrusions form large deposits”, a potential Late Triassic (~204 Ma) buried batholith might have provided abundant ore‐forming materials. However, the top parts of the Late Cambrian and Early Jurassic granitoids have been denudated, which is unfavourable for significant deposit preservation and mineralization related to the 2 stages of granitoids. This study gives a significant suggestion that exposed, and blind apophyses and dikes should be further considered in the exploration and study of metal deposits in NE China. Three phases of mineralization occurred in the LXZR in the Triassic–Jurassic, namely, porphyry–skarn Cu–Mo polymetallic mineralization (~250–240 Ma), skarn Fe–Pb–Zn polymetallic mineralization (~204–190 Ma), and porphyry Mo polymetallic mineralization (~180–160 Ma). On the basis of regional data, the LXZR experienced subduction and collisional settings during ~260–185 Ma and ~180–160 Ma, respectively. Hence, the Early Triassic (~250–240 Ma) and Late Triassic–Early Jurassic (~204–190 Ma) mineralizations represented by the Baoshan and Cuihongshan deposit...

RETRACTED: Geochronology, geochemistry, and genesis of the Shamai tungsten deposit, Inner Mongolia, NE China

“…There are 1199 known tungsten mineral deposits in China that contain a total of 7.8 Mt contained WO 3 , more than 90% of Chinese tungsten resources are located in the Nanling region of southern China (Sheng et al, 2015). Northeastern China also contains several tungsten deposits (Figure 1), including the porphyry‐type Honghuaerji deposit (Guo et al, 2016), the skarn‐type Cuihongshan deposit (Chen et al, 2019; Zhang et al, 2018) and Gongpengzi deposit (Li et al, 2019), and the quartz‐vein‐hosted Shamai deposit (Hu, 2006; Jiang et al, 2016; Nie et al, 2010; Nie & Jiang, 2011), among others. These tungsten deposits are generally located in the Jilin–Heilongjiang and Da Hinggan Mountains metallogenic provinces, both of which are tectonically associated with the eastern Central Asian Orogenic Belt (CAOB; Figure 1a).…”

Ages and geochemistry of Early Jurassic granitoids in the Lesser Xing’an–Zhangguangcai Ranges, NE China: Petrogenesis and tectonic implications

“…Geochronological dating, including Re-Os isochron ages from molybdenite and zircon U-Pb concordant ages from ore-bearing granitoids, has yielded Early-Middle Jurassic ages (197-161 Ma; Fig. 13C; Chen et al, 2019;Guo et al, 2018;Hou et al, 2018;Tang et al, 2011;Wang et al, 2017b, and references therein), coinciding with the magmatic activity in the LXZR. Furthermore, the LXZR metallogenic belt also displays a roughly north-south distribution (Fig.…”

“…13C), consistent with the subduction direction of the Mudanjiang Ocean. Thus, combined with the regional geological history, these porphyry copper and molybdenum deposits were likely formed in an active continental margin setting, related to the subduction of the Mudanjiang Ocean beneath the Songnen block during the early Mesozoic (Chen et al, 2019;Zhang et al, 2013).…”

Genesis and Prospecting Potential of the Da’anhe Skarn Au Deposit in the Central of the Lesser Xing’an Range, NE China: Evidence from Skarn Mineralogy, Fluid Inclusions and H-O Isotopes

“…Skarn deposits in northeastern China mainly formed in the late Permian-Early Triassic period (Baoshan Cu deposit [10]; Laozuoshan Cu-Au deposit [78]), Jurassic (Cuihongshan Fe-polymetallic deposit [14]; Ergu Fe-Zn polymetallic deposit [12]), and Early Cretaceous (Huanggangliang Fe-Sn deposit [79]; Haobugao Pb-Zn deposit [48]; Xieertala Fe-Zn deposit [80]; Tongshan Cu-Mo deposit [81]), while independent skarn gold deposits formed only in the Early Jurassic period (184-203 Ma, [19,20,43]. From the perspective of magmatic properties related to mineralization, the gabbro-dioritic magma related to the mineralization of the Da'anhe deposit originated from lower crust or mantle wedge metasomatized by subduction fluid, and such magmas are characterized by reducing conditions and a high water content (∆FMQ = 0.17, log(fO 2 ) = −15.11, water content = 6.80 wt.%, [49]).…”

“…However, most of these deposits are calcareous skarn deposits that are composed mainly of iron, copper lead and zinc and are genetically related to the metasomatism of intermediate-acidic plutonic rocks and marble. Examples of such deposits include the Ergu Fe-Zn polymetallic deposit [9][10][11][12], Cuihongshan Fe-Cu-W-Mo polymetallic deposit [13][14][15], and Xulaojiugou Pb-Zn polymetallic deposit [16,17]. The medium-sized Da'anhe gold deposit is the only skarn Au deposit.…”