Mineral exploration is not only a public inquiry after the activity had a positive finding signs of extractive Lay, but the notion that exploration refers to the entire sequence of the work group consisting of:
1. Review (reconnaissance or prospecting or public inquiry) with the aim to find prospects,
2. Prospects of economic assessment has been found, and
3. The tasks set additional ore in a mine
In Indonesia where the agency name, or division of a company's organization, government agencies and research to use the term exploration activities covering from finding prospects to determine the amount of mineral reserves. Conversely there are some countries, like France and the Soviet Union (before the country broke up) who use the term exploration to find activities for prospecting mineralization and economic assessment of prospects (Peters, 1978). Further exploration of mineral terms used in this book means that the entire sequence of events began to search for the location of mineralization to determine the insitu reserve mineralization findings. Further exploration of mineral terms used in this book means that the entire sequence of activities from finding the location of mineralization to determine insitu reserves.
Phasing in Planning Exploration Activities
1. Exploration Stage Introduction
According to White (1997), in this preliminary stage of exploration required level of accuracy is still small so that the maps used in the preliminary exploration is also a small-scale 1: 50,000 to 1: 25,000. The steps undertaken in this phase are:
a. Literature Review
In this phase, before choosing the locations of exploration carried out a study of data and maps of existing (from previous surveys), old records, reports findings, etc., and then selected the area to be surveyed. After site selection is determined the next step, the study geological factors of regional and provincial metallographic from regional geological maps is very important to choose exploration area, because the formation of mineral deposits is influenced and depends on the geologic processes that have occurred, and the signs can be seen in the field.
b. Surveying And Mapping
If the base map (topographic map) of the exploration area is available, then the survey and mapping of outcrop (outcrop) or other geological phenomena can already begun (topographic map scale 1: 50,000 or 1: 25,000). But if no, it is necessary to be done first topographic mapping. If the area has no geological map, then this is very beneficial, because the survey can be directed to look for signs of sediment are looking for (outcrop), complete the geological map and take samples from the outcrop-important outcrop.
Apart from rock outcrop outcrop-extractive carrier or coal (direct target), which should also pay attention to the changes / rock boundary, the orientation of sedimentary rock layers (stance and slope), the orientation of faults and other signs. Important things should be plotted on a base map with the help of tools such as compass geology, inklinometer, altimeter, and natural signs such as hills, valleys, river bend, roads, villages, etc.. Thus the geological maps can be completed or made new (map outcrop).
The signs that have been plotted on the map are then combined and made vertical section or distribution model (geological model). With hepatic geological model is then designed by taking random samples, making the well test (test pit), it trenching, and if necessary be done drilling. These locations should then be plotted correctly on the map (with the help of measuring instruments, theodolite, BTM, etc..).
From this activity will produce the geological model, the sediment distribution model, description of geological reserves, the early levels, etc.. used to determine whether the area in question survey gives a good hope (prospects) or not. If the area has good prospects will be forwarded to the next exploration phase.
2. Exploration Stage Details
After the preliminary exploration stage is known that there are reserves that have good prospects, then continues with the exploration stage of detail (White, 1997). The main activities in this phase is sampling with a closer distance (meeting), namely by extending the test wells or drill holes to obtain more precise data about the distribution and thickness of the reserve (reserve volume), distribution of content / quality of horizontally or upright. Dense sampling of the produced reserves calculated by the measured classification, with a small error (<20%), and thus made the mine planning to be more thorough and risks can be avoided.
Knowledge or more accurate data about the depth, thickness, slope, and the spread of reserves in 3-dimensions (length-thick) as well as data on the strength of rock sampling, ground water conditions, and the distribution of structures (if any) will greatly facilitate the progress of planning mines, width / size of the openings or slope mines. It is also important to plan the production of monthly / annual and election of mining equipment and other aid priorities.
3. Feasibility Study
At this stage made plan production, plan mine development, mining methods, planning tools and mining investment plan. By doing economic analysis based on the model, the production cost of sales and marketing it can be known whether extractive reserves can be mined concerned with the beneficial or not.