GSA Today
Volume 24, Number 9 (September 2014)

About the cover:
Iron-rich silcrete mantles beveled quartzite in south-central South Africa. Deep valleys dissect the landscape and steep hillslopes separate the valley bottoms from the flat, gently sloping pediments. Bierman et al. (this issue, p. 4–11) use measurements of 10Be to show that the pediment surfaces are exceptionally stable landforms. Considered along with cosmogenic analysis of fluvial sediments, they suggest that relief is growing over time as valleys incise ~10 times more quickly than the pediment surfaces erode.

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