| Abstract |
Malawi has a number of geothermal occurrences that are manifested on the surface as warm and hot springs. The northern part of the country has the greatest potential in terms of geothermal occurrences and temperature hence the choice for this study. Structurally, the study area (northern Malawi) lies in the apparent meeting point of three major mobile belts that were formed during the three main Orogenic episodes. These episodes were associated with rifting and faulting of the crust. The movements resulted into formation of geological structures such as faults which are believed to have a direct bearing on the geothermal occurrences in the area. As such, a study was done to assess whether there is any relationship between faults and the occurrence of geothermal springs in the area and whether the faults can be used for geothermal exploration. The study showed that there are two main sets of faults with a general orientation of NE-SW and NW-SE and less pronounced N-S orientation in the area. It was further shown that there is a relationship between faults and the geothermal spring occurrences in the study area. It was established that, apart from being associated with the occurrence of geothermal springs, different types of faults also influence the temperature of geothermal springs in the study area. For instance, geothermal springs associated with border faults registered high temperature readings as compared to those that occur on ordinary faults. In addition to that, fault density analysis showed that areas with a high number of faults were also associated with high number of geothermal occurrences and fewer faults were also associated with less geothermal occurrences. Therefore, fault density analysis can be used to predict areas of geothermal occurrence which means that geological structures such as faults can be used for geothermal exploration in areas of similar geological setting especially in areas where geothermal occurrences are fault controlled. |