Genesis of the Bagenheigeqier Pb–Zn skarn deposit in Inner Mongolia, NE China: constraints from fluid inclusions, isotope systematics and geochronology

Cai, Wei; Wang, Ke-Yong; Li, Jian; Fu, Lijuan; Li, Shunda; Yang, He; Konare, Yassa

doi:10.1017/s0016756820000473

Cited by 5 publications

(3 citation statements)

References 139 publications

(181 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Combined with previous bulksulfur isotope analyses (Figure 10A), high δ 34 S values (up to 5‰) do not exclude a small contribution from wall rocks (sedimentary or metamorphic rocks). Such a sulfur isotopic composition, consistent with the sulfur isotope composition of the other gold deposits in the Luxi district (Figure 10A), is common in skarn-type deposits (e.g., Shu et al, 2013;Peng et al, 2016;Cai et al, 2021).…”

Section: Source Of Ore-forming Materialssupporting

confidence: 77%

Metallogeny of the Yi’nan Tongjing Au–Cu skarn deposit, Luxi district, North China Craton: Perspective from in-suit trace elements, sulfur and lead isotopes of sulfides

Cai

Zhang²,

Liu³

et al. 2023

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

Gold–Cu skarn deposits are characterized by a diverse mineral assemblage, whose in-situ major/trace elements and isotope compositions can provide key constraints to the migration and enrichment of Au during hydrothermal processes. The Yi’nan Tongjing Au–Cu deposit is located in the central part of the Luxi district, and both skarn and Au–Cu ore bodies occur at the contact between the Early Cretaceous diorite porphyry and the Neoproterozoic to Cambrian carbonate rocks. Five stages of mineralization were identified: 1) early skarn (garnet–diopside–wollastonite); 2) late skarn (magnetite–epidote–actinolite±tremolite); 3) oxide (specularite–hematite); 4) sulfide (pyrite–chalcopyrite–sphalerite–quartz–chlorite); and 5) late quartz–calcite. The mineralization process in the Tongjing Au-Cu deposit was revealed by detailed scanning electron microscope-backscattered electron imaging, electron probe microanalysis, in-situ trace element, sulfur and lead isotope analysis. Magnetite is enriched in chalcophile elements (Cu, Zn, Pb), Co and Ni, probably due to hydrothermal overprint. The substitution of As and other elements in the formation of pyrite is conducive to the entry of Au into pyrite. The increase of Se and As contents in pyrite from stage IVa to IVb indicates that the temperature, salinity and oxygen fugacity of the ore-forming fluid decrease while the pH rises, resulting in the unloading of Au. The temperature of Au mineralization based on the Se content in pyrite does not exceed 300°C. Furthermore, V positively correlated with Ti and Ni/Cr ratios ≥1 in magnetite and most Co/Ni ratios in pyrite >10 all confirm their hydrothermal origins. The restricted sulfur (δ34SV-CDT = −0.5–1.2‰; mean = 0.4‰) and lead (206Pb/204Pb = 17.323–17.383; 207Pb/204Pb = 15.424–15.452; 208Pb/204Pb = 37.367–37.454) isotopic compositions suggest that the deep magma provided the primary mineralized material, accompanied by a relatively small amount of shallow crustal material. The Yi’nan Tongjing Au–Cu skarn deposit was formed in the Early Cretaceous, which is an important metallogenic response to the strong decratonization of the North China Craton induced by the paleo-Pacific Plate roll-back. This study shows that there is a large potential of Early Cretaceous skarn mineralization in the Luxi district.

show abstract

Section: Source Of Ore-forming Materialssupporting

confidence: 77%

Metallogeny of the Yi’nan Tongjing Au–Cu skarn deposit, Luxi district, North China Craton: Perspective from in-suit trace elements, sulfur and lead isotopes of sulfides

Cai

Zhang²,

Liu³

et al. 2023

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Studies showed that the distribution of lead-zinc deposits was basically consistent with that of skarn (Cai et al, 2021). The types and characteristics of pollutants in the surrounding environment created by lead-zinc mines were quite different depending on the topography, climate, as well as soil physical and chemical properties of the contaminated area (Feng et al, 2020).…”

Section: Analysis Of Mineral Species Differences Of Heavy Metal Pollu...mentioning

confidence: 92%

Impacts of the development of mineral metal resources on surface water quality in the Mongolian Plateau based on meta-analysis

Liu

Jin³

et al. 2022

Front. Environ. Sci.

View full text Add to dashboard Cite

The mining of metal resources is one of the major sources of heavy metals in surface water, but studies on the different characteristics of the impact of the exploitation of mineral metal resources on surface water from a large-scale perspective are lacking. In the present study, we quantified the impacts of mineral metal resource development on As, Cu, Cr, Pb, Zn, Hg, Ni, Cd, Mn, and Fe in the overlying water and sediments of surface water under different scenarios (i.e., different geographic units and different mined metal types) using meta-analysis for the Mongolian Plateau of Mongolia and the Inner Mongolia Autonomous Region of China, which is rich in mineral metal resources and has high exploitation and use intensity. Finally, funnel plots and Egger’s regression analysis were used to test the publication bias of the data. The results show that the order of heavy metal content in the overlying water of the Mongolian Plateau was Fe > Mn > As > Zn > Cu > Pb > Cr > Ni > Cd > Hg, and the order of heavy metal content in the sediment was Fe > Mn > Zn > Cr > Pb > Ni > Cu > As > Cd > Hg. In addition, As, Cr, Zn, Hg, Cd, and Pb in overlying water exceeded the standard to different degrees, among which the contents of As and Pb were 1.4 and 1.3 times higher than the World Health Organization guideline, and the contents of Cr, Pb, Hg, Cd were 1.5, 1.3, 25.4, 2.6 times Chinese environmental quality standards for surface water, and the contents of As, Pb, Zn, Hg were 1.4, 1.3, 4.7, 12.7 times Mongolian water quality standards, respectively. The content of As in sediments was 2.6 times the background value of soil environmental quality in Inner Mongolia. Significant differences existed in the content of heavy metal pollutants in surface water of different countries; the content of heavy metals in the overlying water was significantly higher in Inner Mongolia Autonomous Region of China than in Mongolia. Copper and molybdenum polymetallic mines significantly increased the content of Cd, Cr, Cu, Fe, Hg, Pb, and Zn in the overlying water, while the content of As, Cr, Pb, and Zn in overlying water increased significantly due to lead–zinc mining. However, the mining of gold–silver, lead–zinc, copper–molybdenum, and other polymetallic mines all significantly affected the concentration of As in sediments. The results of the present study can provide data support for environmental protection and the restoration of surface water in metal mining areas of the Mongolian Plateau.

show abstract

“…Skarn Au-Cu deposits, despite being less frequent than porphyry Cu-Au deposits, often exhibit elevated grades of gold and copper [6], thus garnering considerable attention from economic geologists [4,[6][7][8]. Previous research endeavors aimed at comprehending the genesis of Au-Cu skarn deposits and mainly focused on skarn minerals (e.g., garnet), sulfide geochemistry (pyrite and chalcopyrite), and isotopes (S and Pb), contributing to our understanding of the mineralization process (e.g., [7][8][9][10]). However, the understanding of the mechanisms that trigger gold and copper precipitation in skarn deposits, including water-rock reactions and fluid mixing, remains inadequate.…”

Section: Introductionmentioning

confidence: 99%

Genesis of the Yi’nan Tongjing Gold–Copper Skarn Deposit, Luxi District, North China Craton: Evidence from Fluid Inclusions and H–O Isotopes

Cai,

Liu,

Zhang

et al. 2023

Minerals

View full text Add to dashboard Cite

The Luxi district presents an exceptional research area for the investigation of the significant role played by magma exsolution fluids in the mineralization process of Au–Cu deposits. A particularly noteworthy occurrence within this region is the Yi’nan Tongjing Au–Cu skarn deposit, situated in the central-southern part of the Luxi district. This deposit primarily occurs in the contact zone between the early Cretaceous Tongjing complex and the Proterozoic to Cambrian sequences. The ore formation process observed in this deposit can be categorized into three distinct stages: (I) thermal metamorphism, (II) prograde alteration, and (III) retrograde alteration. The retrograde alteration stage is further divided into four sub-stages: late skarn (III-1), oxide (III-2), sulfide (III-3), and late quartz-calcite (III-4). It is primarily during the III-3 sub-stage that gold mineralization occurs. Petrographic analysis has identified three types of fluid inclusions (FIs) within garnet, quartz, and calcite grains. These include liquid-rich two-phase aqueous FIs, vapor-rich two-phase aqueous FIs, and halite-bearing multi-phase FIs. The homogenization temperatures of fluid inclusions from stages II, III-3, and III-4 range between 430–457 °C, 341–406 °C, and 166–215 °C (first to third quartiles), respectively. The garnet samples from stage II exhibit hydrogen and oxygen isotope compositions (δ18OH2O = 6.8‰ and δD = −73‰) that are indicative of a typical magma source. However, the hydrogen and oxygen isotopes of sub-stages III-1, III-2, and III-3 (δ18OH2O = 7.32‰ to 9.74‰; δD = −107‰ to −81.9‰) fall below the magma water box while the hydrogen and oxygen isotope values of III-4 (δ18OH2O = −5.3‰ to −0.9‰ and δD = −103.8‰ to −67‰) tend to move towards the meteoric water line. Furthermore, the ore-forming fluid displays characteristics of a mixture between the crustal and mantle fluids. The Tongjing complex occurred along a weakened fault zone, initiating a process of thermal metamorphism upon contact with the wall rock. This thermal metamorphism resulted in the formation of diverse assemblages, including hornfels, reaction skarns, and skarnoids. Subsequently, the upward movement of ore-forming fluids triggered exsolution which led to the establishment of a high-temperature, medium-salinity NaCl–H2O system with a single phase at depths ranging from 1–3 km. This marked the formation of the prograde alteration stage. Afterward, the ore-forming fluid underwent water–rock interactions and the admixture of meteoric water at a depth of 1–2 km. These processes facilitated phase separation, commonly referred to as boiling, resulting in the transformation of the ore-forming fluid into higher salinity fluids and lower-density gases. This evolutionary transition ultimately induced the precipitation and liberation of gold and copper from the fluid.

show abstract

Genesis of the Bagenheigeqier Pb–Zn skarn deposit in Inner Mongolia, NE China: constraints from fluid inclusions, isotope systematics and geochronology

Cited by 5 publications

References 139 publications

Metallogeny of the Yi’nan Tongjing Au–Cu skarn deposit, Luxi district, North China Craton: Perspective from in-suit trace elements, sulfur and lead isotopes of sulfides

Metallogeny of the Yi’nan Tongjing Au–Cu skarn deposit, Luxi district, North China Craton: Perspective from in-suit trace elements, sulfur and lead isotopes of sulfides

Impacts of the development of mineral metal resources on surface water quality in the Mongolian Plateau based on meta-analysis

Genesis of the Yi’nan Tongjing Gold–Copper Skarn Deposit, Luxi District, North China Craton: Evidence from Fluid Inclusions and H–O Isotopes

Contact Info

Product

Resources

About