Publicación Artículo científico (article). 2012
The Azuaje travertine: an example of aragonite deposition in a recent volcanic setting, N Gran Canaria Island, Spain
Repositorio Institucional del Instituto IMDEA Agua
oai:eprints.imdea-agua.org:111
Repositorio Institucional del Instituto IMDEA Agua
- Rodríguez-Berriguete, A.
- Alonso-Zarza, A.M.
- Cabrera, M.C.
- Rodríguez-González, A.
The Azuaje travertines in the north of Gran Canary Island crop out in the Azuaje Gorge, which is incised into Miocene volcanic breccias of the Roque Nublo Formation. This travertine is interesting because of the scarcity of travertines in the Canary Islands and its close relationship with recent volcanic events. Part of the travertine overlies a lava flow, dated at 2420 ± 40 years BP. The travertine is composed mainly of aragonite in both perched systems on the gorge walls and in gorge bottom deposits parallel to the present stream. Perched systems include deposits from the feeder conduits within the Roque Nublo Formation that spilled out through waterfalls and over barriers. The gorge (valley) bottom system includes barrier and pool deposits. The main laminated facies are composed mostly of large fibrous aragonite crystals, while there are also common micritic and porous microfabrics. Shrubs, coated grains, coated bubbles and rafts are present in many of the deposits. Detailed study of the microfacies shows the presence of sparsely distributed biogenic features. The δ13C values are between + 4.0 and + 11.0‰, and the δ18O values range between − 11.0 and − 2.0‰ VPDB. These δ13C values lie within the range of those of thermogene travertines fed by thermal waters that cooled downstream, as indicated by the increase of the carbon and oxygen isotope values in that direction. The common occurrence of fibrous radial fabrics is interpreted to be due to disequilibrium conditions during aragonite precipitation. Disequilibrium was likely caused by rapid CO2 degassing of the thermal waters that led to a rapid increase in the degree of aragonite saturation. Thus, the morphology of the aragonite crystals and the isotopic composition indicate that the formation of the Azuaje travertine was mostly due to abiogenic processes induced by rapid degassing of thermal waters, linked to the presence of a recent lava flow within the Gorge. In short, the Azuaje travertine shows the important role of volcanic activity in travertine deposition, in the facies distribution as well as in the geochemical signatures of the deposits, and so can be used as a recent analogue for ancient travertine deposits in volcanic settings.
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2 Documentos relacionados
2 Documentos relacionados
E-Prints Complutense. Archivo Institucional de la UCM
oai:www.ucm.es:25233
Artículo científico (article). 2012
THE AZUAJE TRAVERTINE: AN EXAMPLE OF ARAGONITE DEPOSITION IN A RECENT VOLCANIC SETTING, N GRAN CANARIA ISLAND, SPAIN
E-Prints Complutense. Archivo Institucional de la UCM
- Rodríguez Berriguete, Álvaro
- Alonso-Zarza, Ana María
- Cabrera Santana, María del Carmen
- Rodríguez González, Alejandro
The Azuaje travertines in the north of Gran Canary Island crop out in the Azuaje Gorge, which is incised into Miocene
volcanic breccias of the Roque Nublo Formation. This travertine is interesting because of the scarcity of travertines in
the Canary Islands and its close relationship with recent volcanic events. Part of the travertine overlies a lava flow,
dated at 2420±40 years BP. The travertine is composed mainly of aragonite in both perched systems on the
gorge walls and in gorge bottom deposits parallel to the present stream. Perched systems include deposits from
the feeder conduits within the Roque Nublo Formation that spilled out through waterfalls and over barriers. The
gorge (valley) bottom system includes barrier and pool deposits. The main laminated facies are composed mostly
of large fibrous aragonite crystals, while there are also common micritic and porous microfabrics. Shrubs, coated
grains, coated bubbles and rafts are present in many of the deposits. Detailed study of the microfacies shows the
presence of sparsely distributed biogenic features. The δ13C values are between +4.0 and +11.0‰, and the δ18O
values range between −11.0 and −2.0‰ VPDB. These δ13C values lie within the range of those of thermogene
travertines fed by thermal waters that cooled downstream, as indicated by the increase of the carbon and oxygen
isotope values in that direction. The common occurrence of fibrous radial fabrics is interpreted to be due to disequilibrium
conditions during aragonite precipitation. Disequilibrium was likely caused by rapid CO2 degassing of the
thermalwaters that led to a rapid increase in the degree of aragonite saturation. Thus, themorphology of the aragonite
crystals and the isotopic composition indicate that the formation of the Azuaje travertine was mostly due to
abiogenic processes induced by rapid degassing of thermalwaters, linked to the presence of a recent lava flow within
the Gorge. In short, the Azuaje travertine shows the important role of volcanic activity in travertine deposition, in
the facies distribution as well as in the geochemical signatures of the deposits, and so can be used as a recent
analogue for ancient travertine deposits in volcanic settings
Repositorio Institucional del Instituto IMDEA Agua
oai:eprints.imdea-agua.org:111
Artículo científico (article). 2012
THE AZUAJE TRAVERTINE: AN EXAMPLE OF ARAGONITE DEPOSITION IN A RECENT VOLCANIC SETTING, N GRAN CANARIA ISLAND, SPAIN
Repositorio Institucional del Instituto IMDEA Agua
- Rodríguez-Berriguete, A.
- Alonso-Zarza, A.M.
- Cabrera, M.C.
- Rodríguez-González, A.
The Azuaje travertines in the north of Gran Canary Island crop out in the Azuaje Gorge, which is incised into Miocene volcanic breccias of the Roque Nublo Formation. This travertine is interesting because of the scarcity of travertines in the Canary Islands and its close relationship with recent volcanic events. Part of the travertine overlies a lava flow, dated at 2420 ± 40 years BP. The travertine is composed mainly of aragonite in both perched systems on the gorge walls and in gorge bottom deposits parallel to the present stream. Perched systems include deposits from the feeder conduits within the Roque Nublo Formation that spilled out through waterfalls and over barriers. The gorge (valley) bottom system includes barrier and pool deposits. The main laminated facies are composed mostly of large fibrous aragonite crystals, while there are also common micritic and porous microfabrics. Shrubs, coated grains, coated bubbles and rafts are present in many of the deposits. Detailed study of the microfacies shows the presence of sparsely distributed biogenic features. The δ13C values are between + 4.0 and + 11.0‰, and the δ18O values range between − 11.0 and − 2.0‰ VPDB. These δ13C values lie within the range of those of thermogene travertines fed by thermal waters that cooled downstream, as indicated by the increase of the carbon and oxygen isotope values in that direction. The common occurrence of fibrous radial fabrics is interpreted to be due to disequilibrium conditions during aragonite precipitation. Disequilibrium was likely caused by rapid CO2 degassing of the thermal waters that led to a rapid increase in the degree of aragonite saturation. Thus, the morphology of the aragonite crystals and the isotopic composition indicate that the formation of the Azuaje travertine was mostly due to abiogenic processes induced by rapid degassing of thermal waters, linked to the presence of a recent lava flow within the Gorge. In short, the Azuaje travertine shows the important role of volcanic activity in travertine deposition, in the facies distribution as well as in the geochemical signatures of the deposits, and so can be used as a recent analogue for ancient travertine deposits in volcanic settings.
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