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Mineral system modeling approach is useful for assessing the likelihood of occurrences of a type of mineral deposit, which are described using two characteristics: spatial scales modeling and relevant geochemical processes. Possible spatial scales include the craton, region, district, and deposit scales. At each scale, geological modeling is an important aid to exhibit favorable features of mineralization at two-dimension (2D) and three-dimension (3D). Commonly, 3D geometry can be used to restructure geological anomaly at deposit and district/camp scales for quantitative mineral resources assessment. However, they are sensitive to input datasets. Thus, in a sense, the reliability of a 3D geological model depends on how much data have been collected at both ground surface and depth. In addition, the components of dataset also constrain what geological modeling method can be used. In this paper, dynamic updatability is considered as one of the metrics to assess 3D geological modeling methods. This paper discusses different 3D geological modeling processes and compares the ease ability to update. A case study was conducted to analyze the ore-bearing formations and structure of a potential Mississippi valley-type (MVT) Pb–Zn deposit in the Huayuan–Malichang District, Hunan Province, China. The contributions of this study include (1) analyzing what kinds of datasets must be collected for geological modeling at deposit and district scales; (2) the use of multiple 3D modeling processes; and (3) comparing metric what updatability between different 3D modeling processes is. Finally, this paper discusses an integration model based on the above demonstration and other studies.

Several techniques have been proposed to predict undiscovered mineral resources at the regional scale by integrating multiple spatial datasets and mineral deposit models using Geographical Information Systems (GIS). An unresolved issue, however, is that predictive proxies are two-dimensional GIS layers at a regional scale, whereas mineralising processes occur in four dimensions (i.e., space and time). In the past 10 years, mineral system modelling approaches have been proposed and developed for the critical doubt that are described in terms of two characteristics: spatial scales and relevant geochemical processes. This paper demonstrates the modelling and combination of multiple scales based on mineral system prospectivity analysis and then present a resource estimation method that involves the calculation of three variables. In applying a GIS-based approach to a mineral system, we compared the resource estimation in a trap on the district scale to the extrapolation of reserve estimations of representative deposits in the same mineral system. The procedure used for the implementation of this method includes: (i) the incorporation of a descriptive model based on the mineral deposit type; (ii) the digitalization of the favourable characteristics of the type of investigated deposit; (iii) the implementation of the mineral system theory (approach) to pinpoint the locations of potential structural or stratigraphic traps at the district scale using GIS-based two-dimensional prospectivity mapping; (iv) the calculation of similarities and ore-bearing ratios; (v) the restructuring of models of favourable features at multiple scales (i.e., district and ore deposit scales); and (vi) the assessment of undiscovered mineral resources in traps. This method was used to estimate MVT-type Pb-Zn mineralisation in a promising potential region in northwestern Hunan Province, China. In addition, this study is divided into two parts, and this paper mainly describes the methodology.

This paper constitutes the second part of a study called “Mineral system modelling prospectivity analysis for MVT Pb-Zn deposit in northwestern Hunan Province, China”. The methodology is described in Part 1; Part 2 demonstrates the value of 3D modelling at the district and ore deposit scales. The process employed in this paper is as follows: (i) 3D models are constructed at multiple scales (i.e., at the district and ore deposit scales); (ii) an interpretation of the 3D models is presented based on a conceptual geological model; (iii) a map of the mineral potential at depth, relying on the conceptual geological model and 3D geometry data, is delineated and discussed; (iv) calculations of the volume and ore-bearing ratio are improved using 3D geometry; (v) the similarity coefficient used in Part 1 is replaced with the quantitative uncertainty of the 3D models; and (vi) the undiscovered mineral resources are estimated in the study area. To be consistent with Part 1, a case study of the Mississippi Valley-type (MVT) Pb-Zn mineralization in the Huayuan-Malichang district (36 × 24 km2 in northwestern Hunan Province, China), is conducted.

This paper demonstrates a partial least-squares regression (PLS) method for geochemical modelling, and then uses the models and geological favourable features to obtain mineral potential maps. The PLS is one of multivariate analysis technologies, which can identify variations in associations and correlations among geochemical elements and mineralisation. The method is here used to calculate principal components as well as to identify correlations between Pb–Zn (mineralization) and 25 stream sediment elements for constructing geochemical models in the Huayuan-Fenghuang district of northwestern Hunan Province, China. The models showing the distribution of geochemical anomaly are useful in interpreting the distribution of faults and the Cambrian Qingxudong Formation (ore-bearing formation), and to better define the architecture on mineralisation in the study area. In addition, the models and other favourable features (proxies) are easily integrated into single possibility map by Boost Weights-of-Evidence (Boost WofE) approach for targets.