Ore deposits are concentrations of minerals that can be economically extracted and processed. They are the basis of mining engineering, but how do you find them in the first place? In this article, you will learn about some of the methods and techniques that mining engineers use to identify and evaluate ore deposits, from surface mapping to geophysical surveys.
One of the simplest ways to identify ore deposits is to observe and map the surface features of the area of interest. This can include the geology, topography, vegetation, soil, hydrology, and any signs of mineralization, such as outcrops, veins, gossans, or alteration zones. Surface mapping can provide valuable information about the type, size, shape, and orientation of the ore deposit, as well as its potential grade and value. Surface mapping can also help to select the best locations for sampling and drilling.
To identify ore deposits: 1.Geological Survey: Study the Earth's surface and rock formations for clues. 2.Remote Sensing: Use satellite imagery to spot potential areas. 3.Geophysical Tests: Use tools to find subsurface anomalies. 4.Chemical Analysis: Test soil, rocks, and water for ore-related elements. 5.Drilling: Extract samples from underground to confirm ore presence. 6.Mineral Analysis: Identify distinct ore minerals. 7.Resource Assessment: Estimate ore quantity and quality. 8.Economic Evaluation: Check if mining is profitable. 9.Environmental and Regulatory Review: Assess impacts and get approvals. Remember, it's a complex process with no guarantees of success.
It's a lengthier process but let me explain in brief. Ores are identified through a series of geological processes and exploration techniques. A mineral deposit becomes an ore deposit when it can be mined for profit, considering factors such as the amount of known ore, the concentration of the commodity, extraction and processing costs, and market price. We could various techniques of geochemistry, geophysics, and geobotany to identify ore deposits. However, mineral exploration is a complex process with more failures than successes, and the key question is whether it's worth extracting the ore or not.
Another way to identify ore deposits is to collect and analyze samples of rocks, soils, sediments, or water from the area of interest. Sampling can be done by hand, using tools such as hammers, picks, shovels, or augers, or by mechanized methods, such as trenching, pitting, or drilling. The samples are then sent to a laboratory for chemical, mineralogical, or metallurgical analysis, depending on the purpose and type of the ore deposit. Sampling and analysis can provide more detailed and accurate information about the composition, quality, and distribution of the ore deposit, as well as its feasibility and profitability.
For identification of ore deposits, Geological survey is done to study the rock formation and nature of deposit. Core drilling is done to locate the depth, type and nature of ore. sample is sent to lab for analysis of quality and composition.
You can add biochemical sampling, perhaps consistently on the kind of tree and its age and particularly bark, roots and leaves.
A third way to identify ore deposits is to use geophysical surveys, which are methods that measure the physical properties of the earth, such as gravity, magnetism, electricity, radioactivity, or sound. Geophysical surveys can be done from the surface, using instruments such as gravimeters, magnetometers, resistivity meters, or seismographs, or from the air, using planes, helicopters, drones, or satellites. Geophysical surveys can help to detect and map the subsurface structures and anomalies that are associated with ore deposits, such as faults, fractures, intrusions, or ore bodies. Geophysical surveys can also help to estimate the depth, shape, and size of the ore deposit.
A fourth way to identify ore deposits is to use geochemical surveys, which are methods that measure the chemical elements or compounds in the rocks, soils, sediments, or water of the area of interest. Geochemical surveys can be done by collecting and analyzing samples, as described above, or by using remote sensing techniques, such as spectrometry or spectroscopy. Geochemical surveys can help to identify and trace the sources and pathways of mineralization, such as fluids, magmas, or meteorites. Geochemical surveys can also help to determine the type, grade, and value of the ore deposit.
You can also add alteration mapping by identifying clay minerals and mineral assemblage thereby creating zonation and targeting vertical and lateral mineralization disposition.
A fifth way to identify ore deposits is to use geostatistical models, which are mathematical methods that use statistical and spatial analysis to estimate and interpolate the characteristics and variability of the ore deposit. Geostatistical models can be based on the data collected and analyzed from the previous methods, such as surface mapping, sampling, geophysical surveys, or geochemical surveys. Geostatistical models can help to create and visualize three-dimensional representations of the ore deposit, such as maps, cross-sections, or block models. Geostatistical models can also help to calculate and optimize the resources and reserves of the ore deposit.
The final way to identify ore deposits is to design and implement exploration programs, which are systematic and sequential plans that combine and integrate the previous methods, according to the objectives, budget, and timeline of the project. Exploration programs can be divided into stages, such as reconnaissance, prospecting, evaluation, or development, depending on the level of detail and confidence required. Exploration programs can help to identify and prioritize the most promising targets, to reduce the risks and uncertainties, and to increase the chances of success and profitability of the ore deposit.
Les gisements de minerai peuvent être identifiés en utilisant des techniques d'exploration géologique telles que la cartographie géologique, l'échantillonnage des roches et des sols, la prospection géophysique et la prospection géochimique. Ces méthodes permettent de détecter les anomalies géologiques et les concentrations de minéraux qui pourraient indiquer la présence de gisements de minerai. Une fois identifiés, des travaux d'exploration plus approfondis peuvent être entrepris pour évaluer la taille, la teneur et la viabilité économique du gisement.
The calibre and experience of the project geologist should also be considered. By extension junior geologists are groomed and mentored by experienced veterans. Even if a discovery is not made the experience will surely help staff in culling future properties.
A literature search to see what has been developed in the past is also a good idea. Is there a creek that produced a lot of placer gold? Was the source of the gold ever discovered? Never underestimate the power of talking to the locals. Are there any creeks without waterfalls that don't have fish in them? (Natural acidification or heavy metals concentration is a good indicator.) Are there any strangely coloured rocks in the area? If there is low uptake, consider using positive feedback for assistance like offering a bounty for picture an location of the most brightly coloured hillside (looking for gossans).