On the genesis of aluminum-rich speleothems in a granite cave of NW Spain
| Autor: | Jorge Sanjurjo-Sanchez, Carlos Arce Chamorro, Juan Ramón Vidal Romaní, Marcos Vaqueiro-Rodríguez, Victor Barrientos, Joeri Kaal |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | International Journal of Speleology, Vol 50, Iss 1, Pp 25-40 (2021) |
| Druh dokumentu: | article |
| ISSN: | 1827-806X 0392-6672 |
| DOI: | 10.5038/1827-806X.50.1.2358 |
| Popis: | Granite massifs often contain caves, with dimensions ranging from a few meters up to 1,000 m, also referred to as pseudokarst. The speleothems in such caves are mostly composed of either Si-rich (commonly opal-A) or Al-rich authigenic mineraloids. Whereas the formation and geochemical composition of opal-A biospeleothems have been studied and are fairly well understood, knowledge on the Al-rich analogues is scarce. This work reports for the first time a study on the composition, accretion process, age and growth rate of an Al-rich speleothem type flowstone from the A Trapa Cave System (Galicia, NW Spain), developed in a granite cave. To understand the growth process, trickling water was analyzed and the deposition environment inside the cave was characterized. We found that the speleothems are alternating Si- and Al-rich layered deposits formed between 1,635 ± 75 and 1,243 ± 58 cal BP by percolating water that carries underground mineral grains, dissolved ions, and organic matter from soil and the weathered bedrock above the cave. |
| Databáze: | Directory of Open Access Journals |
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