Late Quaternary Rock Glaciers, Mount Kenya, Kenya

Abstract Rock glaciers in Teleki Valley on Mount Kenya exist above 4 000 m below steep valley walls where they are supplied with debris from avalanche couloirs. These valley-side rock glaciers consist of three or four lobes of rubble bounded by transverse furrows resulting from differential movement...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Mahaney, W. C.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1980
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000015331
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015331
Description
Summary:Abstract Rock glaciers in Teleki Valley on Mount Kenya exist above 4 000 m below steep valley walls where they are supplied with debris from avalanche couloirs. These valley-side rock glaciers consist of three or four lobes of rubble bounded by transverse furrows resulting from differential movement. No ice cores were observed in these rubble sheets, but “drunken forest” stands of Senecio keniodendron indicate the probable presence of interstitial ice resulting either from the metamorphism of snow buried under rockfall and slide-rock debris, or from freezing of water beneath the rock mantle. A geological survey of Mount Kenya in 1976 revealed that rock glaciers are anomalous in the Mount Kenya Afroalpine zone above 3 300 m. Analysis of weathering rinds indicates that several rock-glacier lobes were built up over a short interval of time at or near the end of the last glacial maximum (Würm). Oversteepened fronts on the westernmost lobes may have resulted from re-activation coinciding with the advance of glaciers during late Holocene time (<1 000 B.P.). Soils mantle 20% of the rock-glacier surface and have morphological characteristics comparable with soils forming on moraines of late Würm age in upper Teleki, Hausberg, and Mackinder Valleys.