Weathering of granite in Antarctica: I. Light penetration into rock and implications for rock weathering and endolithic communities

Abstract Where rocks are composed of translucent minerals, light penetrates the rock and, in so doing, impacts on the thermal conditions. Where minerals are not translucent all the heat transformation must be at the rock surface, and steep thermal gradients can occur. Where light does penetrate, a c...

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Bibliographic Details
Published in:Earth Surface Processes and Landforms
Main Authors: Hall, Kevin, Guglielmin, Mauro, Strini, Andrea
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2007
Subjects:
Online Access:http://dx.doi.org/10.1002/esp.1618
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.1618
https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.1618
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Summary:Abstract Where rocks are composed of translucent minerals, light penetrates the rock and, in so doing, impacts on the thermal conditions. Where minerals are not translucent all the heat transformation must be at the rock surface, and steep thermal gradients can occur. Where light does penetrate, a component of the incoming radiation is transformed to heat at differing depths within the rock, thereby decreasing the thermal gradient. Equally, light transmissive minerals facilitate endolithic communities, which can also play a role in rock weathering. The attribute of light transmission within rock and the impact this has on the resulting thermal conditions has not been considered within rock weathering studies. An attempt was made to monitor the amount of light penetrating the outer 2 mm of coarse granite under Antarctic summer conditions and to evaluate the thermal impact of this. It was found that the amount of light penetration at this site exceeded modeled or postulated values from biological studies and that it could significantly impact the thermal conditions within the outer shell of the rock. Although the resulting data highlighted a number of flaws in the experimental procedure, sufficient information was generated to provide the first assessment of the range of thermal responses due to light transmissive minerals in rock. Copyright © 2007 John Wiley & Sons, Ltd.