Mineral exploration is the process undertaken by companies, partnerships or corporations to find commercially viable concentrations of minerals through mining. Satellites or reconnaissance aircraft play a significant role in aiding our understanding of mineral mapping due to their capability of detecting hydrothermal alteration minerals and of the sensing surface and subsurface fault zones.
Mineral exploration and extraction are an integral part of many countries’ economic make up and thus optimizing research methods in order to yield optimum returns is of paramount importance. The Egyptian government intends to invest in Golden Triangle (GT), which covers 6,000 square km between the cities of Qena, Safaga and Quseir. Within this investment, the government intends to establish industrial, tourism, agricultural and urban zones by way of optimizing natural resources in the area.
Thus, new and innovative models have been invented in order to modernize mineral mapping. One of these approaches is data integration, as discussed in the paper “An Integrated Approach for Mapping Mineral Resources in the Eastern Desert of Egypt” by Mohamed Abdelkareem, Gamal Kamal El-Din and Ibrahim Osman. The paper was published by the International Journal of Applied Earth Observation and Geoinformation in 2018.
The paper aims to display the key role of an integrated approach for exploring mineral resources in arid regions by analyzing different Geographic Information System (GIS) software packages.
Overview of Remote Sensing Data
In recent decades, we have witnessed a huge improvement in image processing techniques that allow us to visualize and interpret data remotely. This helps to ascertain probable resources prior to embarking on costly ground investigations. Satellites are used as a means to present spectral and geometric information by way of characterizing the hydrothermal alteration minerals which, in turn, provides the exact location of hydrothermal deposits. A form of this technology is Advanced Spaceborne Thermal Emission and Reflection (ASTER). This imaging system allows characterization of specific mineral alterations that confirms hydrothermal activities and thus aids the accurate plotting of mineral resources.
Detecting areas of high mineral resources is a challenge in regions which are difficult to access, and the use of geologic maps does not suffice. The pre-existing problem with geologic maps is that they produce generic information about the area and often contain anomalous data, therefore making it difficult for stakeholders to identify areas of potential mineralization. That is why integration of mapping techniques is paramount to increase yield and profitability.
Data integration is the process of combining data from different sources into a single, unified view. In this case study, it is the unification of ASTER and aeromagnetic data in order to produce a mineral prospect map. Remote sensing data represented by ASTER data will be used to delineate significant areas of alteration zones and marked lithologic contacts. The aeromagnetic data will be used to extract subsurface fault/ fracture zones that represent conductors for hydrothermal solutions. In addition, the study will use geologic, geochemical and field data to compliment the results.
Abu Marwat, the area chosen as the fieldwork location, is situated in the northern section of the Central Eastern Desert (CED) of Egypt, about 400 km south-southeast of Cairo, 70 km from Safaga, and 135 km from Qena.
The study maintains that Egypt needs to modernize and implement integrated data before field investigations. Thus, the main target of the research is to detect the potential areas rich in mineral resources by way of using integrated approaches that have been quantitatively assessed by applying GIS techniques and further validated by field/lab data.
For the process of mineral exploration, a series of evidential maps were obtained to ascertain the potential areas of mineralization. The input data, or in this case evidential maps, contained indirect information on the mineral resources that were to be sourced. This controlled the occurrence of mineral resources. In the study’s model, the mineral deposit relates to the set of geological processes which occur during the rock formation and varies depending on different geological factors such as energy and fluid flows. Based on this concept, fluid movements are more prevalent at areas of intense density within fracture/fault zones as opposed to those of low density. Considerable sizes of fluid run are present at deep-seated geologic structures which then link deep reservoirs in the intermediate crust to the sink zones located at the upper crust.
Therefore, in order to achieve an efficient mineral predictive map several data sets were integrated into two GIS layers including (1) fracture/fault zones; and (2) hydrothermal alteration zones (HAZ). Each one represents an evidence map (predictor) that converts to a GIS based database. Predictive mapping requires the implementation of highly precise and detailed data/images in digital formats with various spatial resolutions. Knowledge-driven multi-criteria (multiclass overlay) that deals with selecting evidence from advanced transformation characterize a mineral system model.
Case Study Results
The integration of ASTER, geologic and aeromagnetic data enabled the characterization of the optimum areas of mineral resources in the central eastern desert of Egypt. The use of integrated data clearly delineated areas of hydrothermal alteration. Furthermore, ASTER data clearly delineated the Subsurface geologic lineaments that were extracted using aeromagnetic data. Overall, results revealed that integration of remote sensing and aeromagnetic anomalies along with field, geologic and geochemical data allowed the mapping of the optimum area of mineral resources. Thus, data integration is crucial in accurately revealing potential areas of mineral resources in arid regions.