Mineral Exploration / Geological Mapping

Region, for example, rich in gold are Aldan, Mamsko-Chuysky district, along the Lena River. Traditionally: Yakutia, Kolyma, Krasnoyarsk Territory, Amur Region. Large mines are located in the north, in Norilsk.

Over the last 10-15 years there has been a significant technological breakthrough related to the improvement of quality and availability of space images. This made it possible to revise traditional approaches to mineral resources forecasting. The world experience of using remote sensing methods has proved its efficiency by the example of searching for copper porphyry, gold and other deposits in Iran, Argentina, China, USA, Canada, etc. All over the world the preparatory stage includes remote sensing methods in the field of exploration, but Russia is still lagging behind. Free space images ASTER, Landsat ETM+, Landsat-8 are used, which have become publicly available relatively recently, besides, these data have proven themselves in the field of geology.

Mandatory field certification is required, as each method allows to define mineral groups with a certain accuracy. These methods were used in combination with traditional geological methods, which allowed to significantly reduce the time of work and reduce the costs of exploration. Based on the study of reference fields, methods of complex analysis of space (including radar), gravimetric and magnetometric survey materials were developed to identify patterns of gold mineralization location

Objectives and principles of exploration of solid mineral deposits. The purpose of exploration is to identify commercial deposits of minerals, obtain mineral reserves explored in the subsoil and other data necessary and sufficient for the rational design and subsequent operation of mining and processing enterprises.

Exploration of mineral deposits

Exploration works are more labor-intensive and expensive than prospecting works. They require a greater volume of both labor, material and energy costs, which are similar in structure to the costs of mining and capital works. These costs should be linked to a gradual progressive increase of exploration information up to optimal volumes (for a certain period), ensuring quality and reliability. As a consequence, the exploration process, unified in methodological terms, develops as if in stages, called stages.

The exploration stage combines a set of geological and exploration works carried out in the field as a whole or in its part in order to solve the tasks set by the project to study the geological heterogeneities of the object, calculate reserves and geological and industrial evaluation.

Initial stage of exploration of mineral deposits

Initial {preliminary) exploration of mineral deposits is carried out after the prospecting and evaluation stage and continues at a higher qualitative level to obtain reliable information capable of providing a reliable geological, technological and economically justified assessment of the industrial significance of the deposit. At this stage, the geological structure of the deposit, its general size and contours are clarified. The exploration of the near-surface part of the deposit with the help of trenches, trenches, pits and shallow wells is completed; large-scale (up to 1 : 500) geological maps are prepared.

The main direction is exploration of the field to the depth of horizons available for development. It is carried out mainly by drilling wells, and in case of complex geological structure of the field - in combination with underground mining. In the process of these works and geophysical studies, the morphology of mineral bodies, their internal structure, conditions of occurrence and qualitative composition are clarified.

Technological samples are taken for laboratory testing of the main natural types of ores, based on the results of which the allocation of industrial types and grades of ores is planned. In addition, hydrogeological, engineering-geological, mining-geological and other natural conditions affecting the opening and development of the deposit are studied. Such study should ensure the possibility of calculating reserves in categories C, and C2. The ratio of reserves of these categories depends on the complexity of the geological structure of the deposit and the variability of the main parameters of ore bodies.

Based on the results of preliminary exploration, temporary conditions are developed and a technical and economic report is prepared on the feasibility of commercial development of the deposit and detailed exploration.

Detailed exploration of mineral deposits

Detailed exploration of mineral deposits is carried out on deposits positively assessed by preliminary exploration and planned for commercial development in the next 5-10 years. It prepares deposits for transfer to industrial use in accordance with the requirements of classification of reserves of deposits and inferred resources of solid minerals. The required number of detailed explored reserves is determined on the basis of the production capacity of the future enterprise and the normal period of supplying it with these reserves. The detail of studies is increased in the areas of priority mining.

Along with these, the reserves of minerals occurring together with the main minerals are determined, and mineral resources for the production of construction materials are identified.

Based on the results of detailed exploration, a feasibility study of permanent conditions is prepared. According to the approved conditions, mineral reserves are calculated and submitted to the State Commission for Reserves (GKZ) of Russia or the Territorial Commission for Reserves (TKZ).

The previous Regulations on the Staging of Exploration Work envisaged additional exploration stages. Currently, the need for additional exploration is determined by the subsoil user.

Additional exploration of mineral deposits

Additional exploration of mineral deposits that have not been developed by the industry, although explored in detail, may be carried out to obtain additional information required in connection with the revision of the design production capacity of the mining enterprise, the technology of mining and processing of mineral raw materials. The need for additional exploration of a deposit may also be due to the inconsistency of the available geological information with the current classification of reserves and instructions for its application. The methodology and scope of exploration works are determined by the tasks arising therefrom. A report is prepared based on the results of the work, with a recalculation of reserves where necessary.

Additional exploration of a mineral deposit under development is focused on its less studied areas: flanks, deep horizons, isolated ore-productive bodies or deposits. It solves the tasks of detailed study of these areas with replenishment of depleted reserves with proven reserves of high (industrial) categories.

Remote sensing data contributes to mineral exploration and geological mapping by detecting surface expressions associated with mineralization. Features such as altered mineral assemblages, geological structures, and anomalies in vegetation or soil composition provide valuable indicators of potential mineral deposits.

Commonly used remote sensing sensors in mineral exploration include hyperspectral, multispectral, and thermal infrared sensors. Hyperspectral sensors capture detailed information across the electromagnetic spectrum, enabling the identification of specific mineral signatures. Multispectral sensors provide broader coverage, and thermal infrared sensors help detect temperature variations associated with certain mineral deposits.

Spectral analysis of remote sensing data aids in mineral identification by analyzing the unique absorption features in the reflected or emitted electromagnetic radiation. Different minerals exhibit distinct spectral signatures due to their chemical composition, allowing geologists to identify specific minerals associated with potential deposits.

Airborne LIDAR contributes to geological mapping by providing high-resolution and accurate elevation data. It enhances the understanding of topographic features and terrain characteristics, aiding geologists in identifying structural geology, fault lines, and subtle changes in the landscape that may indicate the presence of valuable minerals.

Integrating remote sensing data with GIS technology enhances mineral exploration workflows by providing a spatial context for geological information. This integration allows for the creation of detailed geological maps, spatial analysis, and the visualization of mineral potential. It supports decision-making in the mining industry by facilitating efficient target selection, exploration planning, and resource estimation based on comprehensive geospatial data.

Mineral exploration is the systematic process of searching for commercially viable concentrations of minerals. This process involves a variety of activities aimed at discovering new mineral deposits, assessing their size and quality, and evaluating the feasibility of mining them. The main stages of mineral exploration include:

1. Prospecting: The initial search for mineral deposits using various methods such as geological surveys, satellite imagery, aerial photography, and field reconnaissance.

2. Geological Mapping: Detailed mapping of the geology of an area to identify rock types, structures, and other features that may indicate the presence of mineral deposits.

3. Geochemical Surveys: Collecting and analyzing samples of soil, rock, water, and vegetation to detect anomalies in the concentration of certain elements, which can indicate the presence of mineralization.

4. Geophysical Surveys: Using physical methods to detect and map subsurface features. Techniques include magnetic, gravity, seismic, and electrical methods to identify anomalies that may correspond to mineral deposits.

5. Drilling: Drilling holes into the ground to collect core or cuttings samples from below the surface. This helps determine the depth, thickness, and grade of the mineral deposit.

6. Sampling and Assaying: Collecting and analyzing samples to determine the concentration of valuable minerals. Assaying provides critical data on the quality and quantity of the mineral.

7. Resource Estimation: Estimating the size and grade of the mineral deposit based on the collected data. This involves creating models to predict the economic viability of the deposit.

8. Feasibility Studies: Conducting detailed studies to assess the technical, economic, legal, and environmental aspects of developing a mine. This includes evaluating the mining methods, processing techniques, infrastructure requirements, and potential environmental impacts.

9. Permitting and Approvals: Obtaining the necessary permits and approvals from regulatory authorities to develop and operate a mine. This process often involves environmental assessments and community consultations.

The goal of mineral exploration is to identify deposits that can be profitably mined while minimizing environmental impact and ensuring compliance with regulations. Successful exploration can lead to the discovery of new resources, contributing to economic growth and the supply of essential minerals for various industries.

Mineral prospecting is the initial phase of the mineral exploration process, aimed at discovering new mineral deposits. It involves a combination of research, fieldwork, and analysis to identify areas with potential mineral resources. Here are the key activities and methods involved in mineral prospecting:

1. Research and Data Collection:

   • Literature Review: Reviewing existing geological reports, maps, and scientific publications to understand the geology and mineral potential of a region.
   • Historical Data: Analyzing historical mining records and exploration data to identify previously known mineral occurrences.

2. Field Reconnaissance:

   • Site Visits: Conducting on-the-ground surveys to visually inspect rock formations, soil, and other geological features.
   • Rock Sampling: Collecting rock samples for preliminary analysis to identify mineral content and geological characteristics.

3. Geological Mapping:

   • Outcrop Mapping: Documenting exposed rock formations and structures at the surface.
   • Structural Analysis: Studying faults, folds, and other geological structures that may influence mineralization.

4. Geochemical Surveys:

   • Soil Sampling: Collecting soil samples at regular intervals to analyze for trace elements indicative of underlying mineral deposits.
   • Stream Sediment Sampling: Analyzing sediments in streams and rivers, which can carry eroded material from mineralized areas.
   • Vegetation Sampling: Examining plants that may absorb certain elements from the soil, indicating mineral presence below.

5. Geophysical Surveys:

   • Magnetic Surveys: Measuring variations in the Earth's magnetic field caused by different rock types to detect hidden mineral deposits.
   • Gravity Surveys: Measuring variations in the Earth's gravitational field to identify subsurface density anomalies.
   • Electrical and Electromagnetic Surveys: Using electrical currents to detect conductive minerals below the surface.

6. Remote Sensing:

   • Satellite Imagery: Analyzing high-resolution images to identify geological features and alterations indicative of mineralization.
   • Aerial Photography: Using drones or aircraft to capture detailed images of the terrain.

7. Panning and Trenching:

   • Panning: Manually washing sediment to identify heavy minerals like gold.
   • Trenching: Excavating shallow trenches to expose bedrock and obtain continuous samples across a mineralized zone.

8. Sample Analysis:

   • Assaying: Testing collected samples in laboratories to determine their mineral content and concentrations.
   • Petrographic Analysis: Examining rock samples under a microscope to study their mineral composition and texture.

The goal of mineral prospecting is to identify promising areas for more detailed exploration and evaluation. By systematically narrowing down potential sites, prospectors can focus their efforts on locations with the highest likelihood of containing economically viable mineral deposits.