The Geochemical Data Imaging and Application in Geoscience: Taking the Northern Daxinganling Metallogenic Belt as an Example

A controlled-source audio-frequency magnetotelluric (CSAMT) survey has been carried out to investigate potential iron (Fe) and polymetallic (Pb-Zn-Cu) deposits in Longmen region, which is one of the main metallogenic belts in southern China. Conducting geophysical surveys in this area is quite difficult due to mountainous terrain, dense forest, and thick vegetation cover. A total of 560 CSAMT soundings were recorded along twelve surveying lines. Two-dimensional Occam’s inversion scheme was used to interpret these CSAMT data. The resulting electric resistivity models showed that three large-scale highly conductive bodies exist within the surveying area. By integrated interpretation combined with available geologic, geophysical, and geochemical data in this area, three prospective mineral deposits were demarcated. Based on the CSAMT results, a borehole penetrating approximately 250-m depth was drilled at the location of 470 m to the northwest end of line 06, defined with a massive pyrite from the depth of 52–235 m with 7%–16% Fe content, as well as locally high-grade Pb-Zn- and Ag-Ti-bearing ores.

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Identifying Geochemical Anomalies Associated with Gold Mineralization Using Factor Analysis and Spectrum–Area Multifractal Model in Laowan District, Qinling-Dabie Metallogenic Belt, Central China

Minerals ◽

10.3390/min10030229 ◽

2020 ◽

Vol 10 (3) ◽

pp. 229

Author(s):

Ruoyu Wu ◽

Jianli Chen ◽

Jiangnan Zhao ◽

Jinduo Chen ◽

Shouyu Chen

Keyword(s):

Factor Analysis ◽

Gold Mineralization ◽

Fractal Model ◽

Central China ◽

Geochemical Data ◽

Geochemical Anomalies ◽

Theoretical Support ◽

Metallogenic Belt ◽

Spectrum Area ◽

Anomaly Map

The Laowan deposit is a typical gold deposit in the Qinling-Dabie metallogenic belt, which produces the most gold resources in Central China. After being explored for decades, follow-up exploration requires additional theoretical support. In this study, the factor analysis (FA) and spectrum–area (S–A) multifractal model were used to process multi-element geochemical data from 369 samples collected in the study area for identifying the geochemical anomalies associated with gold mineralization. The results showed that: (1) the mean Au content in this region is up to 1000 times higher than the Au background values of the upper crust of the South Qinling unit; (2) the factor analysis revealed that Au, Ag, Cu, As, Sb, and S can be used as direct ore-prospecting criteria; (3) the observed elemental zonation is consistent with the zonation of metallic elements in the magmatic–hydrothermal system. This supports the magmatic–hydrothermal origin of the Laowan deposit; (4) the spectrum–area fractal model can help to decompose the geochemical patterns in a complex geological setting. The decomposed geochemical anomaly map obtained by the S–A multifractal model indicated that highly anomalous areas have a great relationship with the Au occurrence and can be a guidance for further exploration in the study area.

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3D Primary Geochemical Halo Modeling and Its Application to the Ore Prediction of the Jiama Polymetallic Deposit, Tibet, China

Geofluids ◽

10.1155/2021/6629187 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Zhongping Tao ◽

Bingli Liu ◽

Ke Guo ◽

Na Guo ◽

Cheng Li ◽

...

Keyword(s):

Cross Sections ◽

Three Dimensional ◽

Mineral Resources ◽

Principal Component ◽

Kernel Principal Component Analysis ◽

Geochemical Data ◽

Entropy Model ◽

Uncertainty Prediction ◽

Polymetallic Deposit ◽

Metallogenic Belt

The identification of primary geochemical haloes can be used to predict mineral resources in deep-seated orebodies through the delineation of element distributions. The Jiama deposits a typical skarn–porphyry Cu–polymetallic deposit in the Gangdese metallogenic belt of Tibet. The Cu–polymetallic skarn, Cu–Mo hornfels, and Mo ± Cu porphyry mineralization there exhibit superimposed geochemical haloes at depth. Three-dimensional (3D) primary geochemical halo modeling was undertaken for the deposit with the aim of providing geochemical data to describe element distributions in 3D space. An overall geochemical zonation of Zn(Pb) → Au → Cu(Ag) → Mo gained from geochemical cross-sections, together with dip-direction skarn zonation Pb–Zn(Cu) → Cu(Au–Ag–Mo) → Mo(Cu) → Cu–Mo(Au–Ag) and vertical zonation Cu–(Pb–Zn) → Mo–(Cu) → Mo–Cu–(Ag–Au–Pb–Zn) → Mo in the #24 exploration profile, indicates potential mineralization at depth. Integrated geochemical anomalies were extracted by kernel principal component analysis, which has the advantage of accommodating nonlinear data. A maximum-entropy model was constructed for deep mineral resources of uncertainty prediction. Three potential deep mineral targets are proposed on the basis of the obtained geochemical information and background.

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Application of singularity analysis for mineral potential identification using geochemical data — A case study: Nanling W–Sn–Mo polymetallic metallogenic belt, South China

Journal of Geochemical Exploration ◽

10.1016/j.gexplo.2013.08.006 ◽

2013 ◽

Vol 134 ◽

pp. 61-72 ◽

Cited By ~ 32

Author(s):

Yue Liu ◽

Qiuming Cheng ◽

Qinglin Xia ◽

Xinqing Wang

Keyword(s):

South China ◽

Singularity Analysis ◽

Geochemical Data ◽

Mineral Potential ◽

Metallogenic Belt

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Geology and Geochemistry of Selected Gold Deposits in the Ailaoshan Metallogenic Belt, China: Origin of Ore-Forming Fluids

Minerals ◽

10.3390/min11111276 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1276

Author(s):

Yang Li ◽

Denghong Wang ◽

Chenghui Wang ◽

Yan Sun ◽

MIMA Pu-chi

Keyword(s):

Host Rock ◽

Large Scale ◽

Gold Mineralization ◽

Mining Area ◽

Gold Deposits ◽

Pb Isotopes ◽

Late Triassic ◽

Geochemical Data ◽

Continental Scale ◽

Metallogenic Belt

The formation of the Ailaoshan metallogenic belt was the result of: the Neoproterozoic super mantle plume, the Indosinian and South China blocks in the Late Triassic after the Paleo-Tethys Ocean closure, and Oligocene-Eocene continental-scale shearing related to the India-Eurasia collision. It is one of the most important Cenozoic gold ore province in the world. In this paper, the geological characteristics, isotopic geochemistry, and geochemical data of ore-forming fluids of four large-scale gold deposits in the Ailaoshan metallogenic belt (Mojiang Jinchang, Zhenyuan Laowangzhai, Yuanyang Daping, and Jinping Chang’an) are comprehensively compared. The features of host-rock alteration, metallogenetic periods and stages, geochronology, fluid inclusion, and C-H-O-S-Pb isotopes of gold deposits are summarized and analyzed. The gold mineralization in the Ailaoshan metallogenic belt occurred mostly in 50–30 Ma, belonging to the Himalayan period. The gold mineralization is closely related to silicification, argillation, carbonation, and pyritization due to the strong mineralization of hydrothermal fluid, the development of alteration products, and the inconspicuous spatial zonation of alteration types. The ore-forming fluid is mainly composed of mantle fluid (magmatic water) and metamorphic fluid (metamorphic water). The ore-forming materials of the Jinchang, Chang’an, and Laowangzhai gold deposits mainly originate the host-rock strata of the mining area, and the carbon is more likely to from marine carbonate. The carbon in the Daping gold deposit from the original magma formed by the partial melting of the mantle. Pb isotopes have characteristics of crustal origin, accompanied by mixing of mantle-derived materials and multisource sulfur mixing, and are strongly homogenized.

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