| dc.description.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. | en |
