The Burren: a glacial,karstic and biokarstic expression of a limestone plateau in western Ireland |
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| Authors: | John P McIlroy de la Rosa |
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| Institution: | Agri‐Environment Branch, Agri‐Food and Biosciences Institute, Belfast, UK |
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| Abstract: | The term glaciokarst describes a landscape where both glacial and karstic processes have contributed to geomorphological evolution and has been applied to a range of environments from the high arctic to the alpine Mediterranean. Nevertheless, glaciokarstic environments globally often exhibit significant variation in geomorphological processes and landforms due to these geographical differences. The Burren, County Clare, Republic of Ireland, is often quoted as a quintessential glaciokarstic landscape. However, the Burren and other similar environments would appear to lean towards one end of the glaciokarst spectrum, where solutional and biological processes have been dominant throughout the Holocene, in contrast to ice‐dominated glaciokarsts where karstic and biokarstic processes are temperature‐limited and cryospheric processes remain the principal geomorphological agents. Holocene landscape evolution and the development of a range of meso‐, micro‐ and nano‐scale karren features on limestone surfaces appears to be largely biokarstic in origin. Karstification of many glacially scoured limestone pavements would have begun under acidic soil cover, with biological soil processes contributing to smooth, rounded cryptokarstic surface forms. Holocene soil erosion is attributed to anthropogenic activity, climatic fluctuations and the evolution of the karstic groundwater system leading to vertical soil loss through widening grikes. Exposed limestone pavements subject to subaerial conditions often exhibit extensive lichen colonization which has been shown to influence the overall rate of karstification and contribute to the development of micro‐ and meso‐scale bioweathering features. Where cryptokarstic features have been exhumed from beneath soil cover, their evolution under subaerial conditions leads to intermediate, polygenetic karren features. In light of our current understanding of the Burren landscape, it is proposed that the term glaciobiokarstic may be a better expression to encompass the biological processes that have played a fundamental role in the evolution of the Burren and similar landscapes, without neglecting the contribution of glacial and inorganic karstic processes. Copyright © 2016 John Wiley & Sons, Ltd. |
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| Keywords: | karst burren carboniferous limestone glaciokarst biokarst |
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