| Summary: | This study aimed to assess the chemical composition of rocks in Lodwar and its surroundings to understand their potential influence on groundwater quality. A total of 69 rock samples were collected in February and May 2018 during geological mapping and water sampling activities. The samples were analyzed for major oxides, including SiO2, Al2O3, CaO, MgO, Na2O, K2O, TiO2, MnO, Fe2O3, and Loss on Ignition (LOI) using X-ray fluorescence (XRF) at the Department of Mines and Geology in Kenya. Quality control measures for the whole-rock analysis included ensuring that the results of each sample sum to >99.99% or 100%, duplicate sample testing, and calibration of XRF instruments to ensure accuracy and precision. Additionally, the rock samples were carefully georeferenced and packaged under appropriate conditions to avoid contamination during transport
and analysis. Related publications: Tanui et al., 2021. Petrography and Geochemistry of the Rocks in Lodwar, Kenya and their Influences on Groundwater Quality. Africa Journal of Physical Sciences Vol 6. pp. 15-44. https://uonjournals.uonbi.ac.ke/ojs/index.php/ajps/article/view/1026/932 (https://ora.ox.ac.uk/objects/uuid:775da78c-a7a7-47bf-b296-9ac5e88948f7)
Methodology: Samples were prepared for analysis using the lithium metaborate fusion procedure and replicated analyses for each sample. The LOI was determined by weight loss measurement upon heating one-gram split sample at 95°C for 90 minutes. Fifty-four of the samples were ground and analyzed for major elements including Na, Mg, Al, P, S, K, Ca, Fe, and Mn and for trace elements such as Ti, Cr, Co, Ni, Cu, Zn, As, Se, Mo, and Pb elements at International Centre of Agriculture and Forestry (ICRAF) lab by X-ray diffraction (XRD) Tracer 5i and vacuum technology were used in quantitative analysis of lighter elements. The acquired data was filtered using R Knime Application in parts per million (ppm) and subsequently uploaded into the
database for analysis. The results in ppm were divided by 10,000 to convert to a weight percent.
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