Publications


2017

  2017.  Mapping of Hydrothermal Minerals Related to Geothermal Activities Using Remote Sensing and GIS: Case Study of Paka Volcano in Kenyan Rift Valley. International Journal of Scientific Research and Management. 8(5):711-725. AbstractFull Text

Remote sensing investigations combined with Geographical investigation systems (GIS) provide a rapid and cost-effective method for prospecting hydrothermal and geothermal systems. Most geothermal systems in Kenya are found in remote areas where accessibility is difficult. This study was carried out on Paka volcano which is located in the Kenyan rift valley. The aim of the study was to use remote sensing and GIS to investigate hydrothermal minerals and structures associated with geothermal activities. The study involves use of Landsat TM image classification using ENVI 5.1 and ArcGIS. Lineament extraction was done using PCI geomatics 2015 while Rose diagrams were generated using Rockworks 16. The research has shown that lithological, hydrothermal mineralization and structural maps can be generated form Landsat TM images using remote sensing and GIS. It has been shown that faults trend in the Northeast, North and Northwest direction. Hydrothermal minerals that are rich in iron and clays occur on Paka volcano mountain and its neighbouring areas.

2016

WASWA, AARONK, Wamalwa RN, Nyamai CM, Ambusso WJ, Mulwa J.  2016.  Structural Controls on the Geochemistry and Output of the Wells in the Olkaria Geothermal Field of the Kenyan Rift Valley. International Journal of Geosciences. 7(11):1299. AbstractFull Text

The Olkaria geothermal field is located in the Kenya Rift valley, about 120 km from Nairobi. Geothermal activity is widespread in this rift with 14 major geothermal prospects being identified. Structures in the Greater Olkaria volcanic complex include: the ring structure, the Ol’Njorowa gorge, the ENE-WSW Olkaria fault and N-S, NNE-SSW, NW-SE and WNW-ESE trending faults. The faults are more prominent in the East, Northeast and West Olkaria fields but are scarce in the Olkaria Domes area, possibly due to the thick pyroclastics cover. The NW-SE and WNW- ESE faults are thought to be the oldest and are associated with the development of the rift. The most prominent of these faults is the Gorge Farm fault, which bounds the geothermal fields in the northeastern part and extends to the Olkaria Domes area. The most recent structures are the N-S and the NNE-SSW faults. The geochemistry and output of the wells cut by these faults have a distinct characteristic that is the N-S, NW-SE and WNW-ESE faults are characterized by wells that have high Cl contents, temperatures and are good producers whereas the NE-SW faults, the Ring Structure and the Ol’Njorowa gorge appear to carry cool dilute waters with less chloride concentration and thus low performing wells. Though the impacts of these faults are apparent, there exists a gap in knowledge on how wide is the impact of these faults on the chemistry and performance of the wells. This paper therefore seeks to bridge this gap by analysis of the chemical trends of both old wells and newly drilled ones to evaluate the impacts of individual faults and then using buffering technique of ArcGis estimate how far and wide the influence of the faults is. The data was obtained after the sampling and analysis of discharge fluids of wells located on six profiles along the structures cutting through the field. Steam samples were collected with a stainless steel Webre separator connected between the wellhead and an atmospheric silencer on the discharging wells whereas the analysis was done in house in the KenGen geochemistry laboratory. The results indicates that Olkaria field has three categories of faults that control fluid flow that is the NW-SE trending faults that bring in high temperature and Cl rich waters, and the NE-SW trending Olkaria fracture tend to carry cool temperature waters that have led to decline in enthalpies of the wells it cuts through. The faults within the Ol Njorowa gorge act to carry cool, less mineralized water. Though initially, these effects were thought to be in shallow depths, an indication in OW-901 which is a deeper at 2200 m compared to 1600 m of OW-23 well that proves otherwise. This is, however, to be proved later as much deeper wells have been sited.

WASWA, AARONK, MATHU ELIUDM, Nyamai CM, Ichang’i DW.  2016.  NEW FINDINGS OF THE TECTONIC CHARACTERISTICS OF THE EAST AFRICAN OROGENY IN THE KITUI – TAITA HILLS, S.E KENYA, 27 August, 2016. 35TH INTERNATIONAL GEOLOGICAL CONGRESS. , CAPE TOWN, SOUTH AFRICA
Masinde, A, Simiyu C, Murunga I, Muia G, Waswa A, Barongo J.  2016.  A Preliminary Assessment of the Hydrocarbon Potential of Kerio Valley Basin: Gravity and Magnetic Interpretation. IOSR Journal of Applied Geology and Geophysics . 4(3):50-56.g0403015056.pdf
Waswa, AK, Nyamai CM.  2016.  THE GEOLOGY AND MINERAL RESOURCES POTENTIAL OF KENYA , 24 Mar. 2016. Symposium on Capacity Building in Sustainable Resource Development in Africa. , NAIROBI

2015

Mathu, EM, Waswa AK, Kariuki PC, Kianji GK.  2015.  THE MIDDLE EASTERN COUNTIES IN KENYA: AN AWAKENING GIANT IN MINING AND IDEAL FOR MINING INVESTMENT, 19 NOV.2015. GEOEACE 2015. , NAIROBI
WASWA, AARONK, Nyamai CM, Mathu E, Ichang'i D.  2015.  Application of Magnetic Survey in the Investigation of Iron Ore Deposits and Shear Zone Delineation: Case Study of Mutomo-Ikutha Area, SE Kenya. International Journal of Geosciences,. 6(7):729-740.
Githinj, TW, Nyamai CM, Kutukhulu AW.  2015.  Overview of mineral processing and beneficiation in Kenya. Mineral processing and beneficiation. , New Delhi (India): NAM S $ T
WASWA, AARONK, Nyamai CM, Mathu EM, Ichang'i D.  2015.  Integration of Geological Mapping and Remote Sensed Studies for the Discovery of Iron – Ore Mineralization in Mutomo – Ikutha Area, SE Kenya. Universal Journal of Geoscienc e. 3(2):39-50.
WASWA, AARONKUTUKHULU.  2015.  Petrology and iron ore mineralization in the Neoproterozoic Mozambique belt rocks of Mutomo-Ikutha area, in Kitui county, S.E. Kenya. (Dr. C.M. Nyamai, Prof. E. Mathu, Dr. D. ICHANG'I, Eds.)., Nairobi, Kenya: UNIVERSITY OF NAIROBI Abstractabstract.docxabstract.pdf

PETROLOGY AND TECTONO - METAMORPHIC SETTING OF IRON DEPOSITS IN THE MOZAMBIQUE BELT SEGMENT IN MUTOMO - IKUTHA AREA, SOUTH- EASTERN KENYA

Abstract
The study area is bounded by longitudes 380 4’E to 38020’E and latitudes 1048’S to 208’S in South Kitui within the Kitui County occupying about 100 Km2. This area can be accessed from Nairobi-Thika - Kitui ,Nairobi – Machakos-Kitui roads, or from Mombasa –Kibwezi – Ikutha – Mutomo road. Mineral deposits in Kenya occur in different geological settings, such as those associated with Tertiary rocks (Turkana sapphire deposit). Most of the mineral deposits like iron ore located within the Neoproterozoic Mozambique orogenic belt have not been properly evaluated in geological and metallogenical context. This work intends to relate, evaluate and scientifically place the geological framework of iron deposits in Mutomo – Ikutha area of Kitui County, Kenya to the specific events within the litho and tectonothermal evolution of the Mozambique mobile Belt. A thorough investigation of the major and minor geological structures as well as metamorphism will be elucidated in the project area on their role in the formation of iron deposits. The establishment and economic and scientific investigation of iron deposits in the study area for purposes of mining and wealth creation in the region is of great importance in this research work. The application of the research to exploration and development of artisanal mining in Kenya will be successful in terms of prospecting at the regional and scale, by determining the lithological, geochemical and tectonic controls for the mineralization.
The Mozambique Belt has a long and complex history, marked by a succession of major tectonothermal events. This belt runs from Egypt through, Sudan, Ethiopia, Kenya, Uganda, Tanzania and ends in Mozambique. The methods to be used to achieve the aim of this research will include; geological, geochemical and geophysical investigations. Preliminary investigation will be carried out using remote sensed data. Laboratory analysis will include X-ray florescence, X-ray defractometry, and electron Microprobe. The data obtained will be analyzed using Oasis montaj software, Matlab and any other relevant software. The updated geological and structural maps will be compiled using Arc GIS software. This study is expected to provide comprehensive understanding of the tectonothermal scenario and its associated economic mineralization in the Mozambique belt.

2010

WASWA, AARONK.  2010.  GEOPHYSICAL MAPPING OF BURIED RIVER CHANNELS AND OTHER SHALLOW STRUCTURES RECHARGING MAJOR AQUIFERS IN THE LAKE NAKURU BASIN, KENYA RIFT: CASE STUDY FROM KABATINI AQUIFER.. (Barongo J.O, Ed.). Abstractabstract.pdf

Abstract
Buried river channels are increasing becoming the target for groundwater exploration due to the unreliability of surface river channels that have been affected by climate changes. Areas located in urban centers like Nakuru town have high population that dictates the higher demand of water. This research covered the geophysical mapping of buried river channels and other shallow structures recharging major aquifers in the upper Nakuru basin of Kenya rift and in particular the Kabatini area. The project aimed at unveiling scientific knowledge of the subsurface geology using resistivity and magnetic geophysical methods. Solving of water shortages and improvement of livelihood for the people of Nakuru and its neighbor hood through proper and more precise geophysical ground water exploration methods was of great importance. The ultimate goal of the report is to provide guidance to policy makers in decision making especially for ground water extraction in Kabatini aquifer. Geology and hydro-geology of the area have been discussed in the report. The field methods used included vertical electrical sounding, electrical resistivity tomography and magnetic survey. Data processing was done using Earth imager software, RES2DINV, and Euler. The findings of the research ascertain that Kabatini area has underground river channel that flows in the north – south direction. The research also shows that the area has some shallow structures which contain low resistivity materials in different locations. It has also been ascertained that the thickness of Kabatini aquifer is more than 150 m.

2009

WASWA, AARONK, D.N M.  2009.  EVALUATION OF VOLCANIC ROCKS OF NAIROBI AREA FOR USE AS RAW MATERIALS IN THE CONSTRUCTION AND CEMENT INDUSTRY, 12 July. Geological Society of Kenya. , Nairobi, Kenya Abstractabstract_evaluation_of_volcanic_rocks_of_nairobi_area_for_use_as_raw_materials_in_the_construction_and_cement_industry.pdf

Volcanic rocks play an important role in the building and construction industry. Most of the raw materials used by the building industry around Nairobi are the volcanic rocks. The main volcanic rocks considered include Lavas and Pyroclastic rocks. There has been no close monitoring of the proper application of the volcanic raw materials in the construction and cement industry. This might have been resulted due to lack of initiative to study the impacts that results from not applying the right raw materials to the right end use. This has been promoted by fraudulent contractors who could just use this type of rocks without any scientific or mineralogical study. In the world of property valuation, real estate managers have not been able to present objective valuation of such properties due to lack of data on the mineralogical and physical properties of the building materials. Insurance Agencies cannot place realistic premiums on buildings and structures due to lack of geological information of the materials used in the construction.
The aim of this of this research is to provide knowledge on properties of volcanic raw materials and develop their suitable application in construction industry. The method used involved carrying out end use tests which included aggregate test, pozzolanicity tests and building stone tests. Project area is bounded by latitudes 1000’ S and 1030’S and by longitudes 360 30’ and 37000’ E and has an area of approximately 1,200 square miles (31,108 km2). The geological history of Nairobi area is dominated by volcanic activity whereby a thick succession of alkaline lavas associated tuffs began accumulating in Mid-Miocene time and continued into Upper Pleistocene. The result shows that Kapiti phonolites contain zeolites which react with alkalis in concrete to course cracking. It is also noted that most trachytes and tuffs are weak and therefore unsuitable for aggregates. The best material found stronger to be used in aggregate making is the phonolites. It is noted that trachytes and phonolites cannot be used as pozzolana material in cement manufacturing. Most of the volcanic rocks around Nairobi can be used either as walling stones or building stones. The machine cut blocks can only be made from the tuffs because other rocks are harder to be cut.

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