Applying GIS in data dnalysis of Limestone Exploration Data

Abstract

Exploration work generates enormous amount of data. Normally this data is complex and highly variable. Out of this complexity, Geologists are supposed to extract useful information relevant to the purpose of the exploration. It is worth noting that exploration work itself is quiet an expensive exercise. It is also time consuming. More over, it is almost impossible to gain the same information for the same place unless it is redone afresh, especially where deep drilling is involved like in this project. Therefore, each of the several steps involved is done carefully with a lot of accuracy. GIS is a system that enables capturing, storing, retrieving and analyzing this complex data. This project endeavors to demonstrate employment of GIS in exploration of limestone deposit though it can be used for any other type of exploration work. There are various types of exploration. Reconnaissance exploration is where information gathered about a given deposit is not as intensive compared to detailed exploration. The later type of exploration is what this project is based on. For hard, compact and deep seated rock, drilling is the only option to be used to get as much information as possible. All necessary maps are collected and "studied. Geological maps are given special priority to enable precise location of exploration drill holes. After all the paper work these drill holes are physically located on the ground. The number and spacing of the drill holes is determined by the geologist based on the geological formation of the rock. The extracted core logs (Fig. 5 & Fig. 6) are sent to the laboratory for chemical analysis. The chemical analysis of the samples is important. However the amount of sample recovered is equally important too. This is what is referred to as the recovery. Recovery shows the compactness of the rock. It ranges from 0% to 100%. Figures 7,8 and 9 are examples of 100% recovery. This analysis forms part of the attribute table (see Tables 1, 2 &3) that is linked to the spatial data about each individual drill hole. Finally, various layers are created. Based on these layers, maps are generated according to the requirements of the users (see figures 11, 13, 14 &15). It is even possible to calculate the entire reserve quantity as shown in figure 12.These results form the basis of accurate decision making by stakeholders.