Mineralogy and Element geochemistry of volcanic rocks and sediments from the central Rift in Kenya

Wilke, Franziska; Olaka, Lydia; Schleicher, Anja;

2020 || GFZ Data Services

The Central Rift in Kenya (CRK) comprises the lakes Naivasha, Elementaita and Nakuru and the Longonot, Eburru and Menengai volcanos. The alkaline magmas, produced by the volcanoes within the CRK, lead to solid rocks likes trachytes, phonolites, and fewer basalts and accompanied soft rocks like ashes, tuffs, pumices and ignimbrites (e.g. Macdonald et al., 1987; Macdonald, 2014). Lacustrine sediments and beds of diatoms are remnants of former lake level variations caused by climate variability and topographic changes (e.g. Stoof-Leichsenring et al., 2011). The samples have been taken within the frame of a VW-Foundation funded project that tries to detect, map and monitor groundwater pollution from anthropogenic and natural sources. For a previous VW-Foundation funded project (grant 85465), also the groundwater fluoride enrichment in the CRK have been studied (Olaka et al., 2016).
This data report presents the metadata, inclusive GPS data from 52 solid volcanic rock and sediment samples taken during a field excursion during May 2017. A geological map with all data locations is included in this report. After sample preparation, we performed X-ray diffraction (XRD) analyses to get the mineral content and X-ray fluorescence (XRF) as well as Ion-Chromatographic (IC) analyses to get the elemental concentration of those samples. The results are given together with analytical limitations and few additional information despite a graphic visualization of the XRD-data.
The data are presented in tab-delimited text format and described in the dataset description.

Originally assigned keywords

Corresponding MSL vocabulary keywords

MSL enriched keywords

MSL enriched sub domains
  • geochemistry
  • microscopy and tomography
Source http://dx.doi.org/10.5880/gfz.3.1.2020.001
Source publisher GFZ Data Services
DOI 10.5880/gfz.3.1.2020.001
Authors
  • Wilke, Franziska
  • GFZ German Research Centre for Geosciences, Potsdam, Germany;
  • Olaka, Lydia
  • 0000-0002-5917-7586
  • University of Nairobi, Department of Geology, Nairobi, Kenya;
  • Schleicher, Anja
  • 0000-0003-4052-8654
  • GFZ German Research Centre for Geosciences, Potsdam, Germany;
References
  • Doebelin, N., & Kleeberg, R. (2015). Profex: a graphical user interface for the Rietveld refinement programBGMN. Journal of Applied Crystallography, 48(5), 1573–1580. https://doi.org/10.1107/s1600576715014685
  • 10.1107/S1600576715014685
  • Cites
  • Macdonald, R. (1987). Quaternary peralkaline silicic rocks and caldera volcanoes of Kenya. Geological Society, London, Special Publications, 30(1), 313–333. https://doi.org/10.1144/gsl.sp.1987.030.01.15
  • 10.1144/GSL.SP.1987.030.01.15
  • Cites
  • MACDONALD, R., DAVIES, G. R., BLISS, C. M., LEAT, P. T., BAILEY, D. K., & SMITH, R. L. (1987). Geochemistry of High-silica Peralkaline Rhyolites, Naivasha, Kenya Rift Valley. Journal of Petrology, 28(6), 979–1008. https://doi.org/10.1093/petrology/28.6.979
  • 10.1093/petrology/28.6.979
  • Cites
  • Olaka, L. A., Wilke, F. D. H., Olago, D. O., Odada, E. O., Mulch, A., & Musolff, A. (2016). Groundwater fluoride enrichment in an active rift setting: Central Kenya Rift case study. Science of The Total Environment, 545–546, 641–653. https://doi.org/10.1016/j.scitotenv.2015.11.161
  • 10.1016/j.scitotenv.2015.11.161
  • Cites
  • Stoof-Leichsenring, K. R., Junginger, A., Olaka, L. A., Tiedemann, R., & Trauth, M. H. (2011). Environmental variability in Lake Naivasha, Kenya, over the last two centuries. Journal of Paleolimnology, 45(3), 353–367. https://doi.org/10.1007/s10933-011-9502-4
  • 10.1007/s10933-011-9502-4
  • Cites
  • Toby, B. H. (2006). R factors in Rietveld analysis: How good is good enough? Powder Diffraction, 21(1), 67–70. https://doi.org/10.1154/1.2179804
  • 10.1154/1.2179804
  • Cites
Citation Wilke, F., Olaka, L., & Schleicher, A. (2020). Mineralogy and Element geochemistry of volcanic rocks and sediments from the central Rift in Kenya [Data set]. GFZ Data Services. https://doi.org/10.5880/GFZ.3.1.2020.001
Geo location(s)
  • Sample area from the Central Rift in Kenya
Spatial coordinates
  • eLong 36.538278
  • nLat -0.226231
  • sLat -0.944867
  • wLong 36.095739