Late Quaternary primary tephras in Sacred Lake sediments, northeast Mount Kenya, Kenya
Date
2000-05Author
Olago, DO
Street-Perrott, FA
Perrott, RA
Ivanovich, M
Harkness, DD
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
In this paper, a sequence of five Late Quaternary tephras occurring as discrete, well-preserved horizons in lake sediments on the northeastern flank of Mount Kenya are characterised and their ages determined by a combination of high-resolution indirect radiocarbon dating and direct View the MathML source dating. The grain size characteristics suggest that the tephras are of fairly local origin. These NaK-rich alkali pyroclasts with a trachytic chemical composition have a highly correlated chemistry and mineralogy, suggesting that they were probably derived from the same genetic series and possibly erupted from a single source vent. Morphological differences are attributed to the peculiar characteristics of each eruption episode. The magma source was probably a small, highly differentiated magma chamber following the olivine basalt-trachyandesite-trachyte-phonolite series, which broadly reflects the Quaternary rock suite of Mount Kenya.
URI
http://www.sciencedirect.com/science/article/pii/S0899536200000634http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/42921
Citation
Journal of African Earth Sciences Volume 30, Issue 4, May 2000, Pages 957–969Publisher
University of Nairobi Department of Geology