Submarine felsic volcanoes are dominated by hyaloclastic piles hundreds of meters thick, the origin of which, in terms of how and when they form, is far from being completely understood. Here we present a study of the thermal remanent magnetization of the Miocene high- K dacitic El Barronal hyaloclastites (Cabo de Gata, Spain), showing that their formation is dominated by in situ fragmentation with small or negligible transportation and/or rotation of different clasts after their formation. Data indicate that fragmentation progressed down to 210–390 °C, well below the glass-transition temperature estimated at 560–750 ºC depending on the water content of the high-K dacite. Hence, hyaloclastite fragmentation in thick lavas may occur over most of the cooling history, as a result of the progressive access of sea water toward the lava interior by development of a complex network of contraction fractures.
Hyaloclastite fragmentation below the glass transition: example from El Barronal submarine volcanic complex, Cabo de Gata (Spain) / Porreca, M.; Cifelli, F.; Soriano, C.; Giordano, G.; Romano, C.; Mattei, M.; Conticelli, S. - ELETTRONICO. - (2015), pp. 0-0. (Intervento presentato al convegno 26th IUGG, General Assembly 2015, Earth and Environmental Science for the Future tenutosi a Prague, Czech Republic nel June 22- July 2, 2015).
Hyaloclastite fragmentation below the glass transition: example from El Barronal submarine volcanic complex, Cabo de Gata (Spain)
CONTICELLI, SANDRO
2015
Abstract
Submarine felsic volcanoes are dominated by hyaloclastic piles hundreds of meters thick, the origin of which, in terms of how and when they form, is far from being completely understood. Here we present a study of the thermal remanent magnetization of the Miocene high- K dacitic El Barronal hyaloclastites (Cabo de Gata, Spain), showing that their formation is dominated by in situ fragmentation with small or negligible transportation and/or rotation of different clasts after their formation. Data indicate that fragmentation progressed down to 210–390 °C, well below the glass-transition temperature estimated at 560–750 ºC depending on the water content of the high-K dacite. Hence, hyaloclastite fragmentation in thick lavas may occur over most of the cooling history, as a result of the progressive access of sea water toward the lava interior by development of a complex network of contraction fractures.File | Dimensione | Formato | |
---|---|---|---|
2015_IUGG_Porreca+alii_Hyaloclastite.pdf
accesso aperto
Tipologia:
Pdf editoriale (Version of record)
Licenza:
Open Access
Dimensione
636.68 kB
Formato
Adobe PDF
|
636.68 kB | Adobe PDF |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.