Hydrothermal system of Central Tenerife Volcanic Complex, Canary Islands (Spain), inferred from self-potential measurements

Abstract

a b s t r a c tAn extensive self-potential survey was carried out in the central volcanic complex of Tenerife Island (Canary Islands, Spain). A total amount of ~237 km of profiles with 20 m spacing between measurements was completed, including radial profiles extending from the summits of Teide and Pico Viejo, and circular profiles inside and around Las Cañadas caldera and the northern slopes of Teide and Pico Viejo. One of the main results of this map-ping is the detection of well-developed hydrothermal systems within the edifices of Teide and Pico Viejo, and also associated with the flank satellite M. Blanca and M. Rajada volcanoes. A strong structural control of the surface manifestation of these hydrothermal systems is deduced from the data, pointing to the subdivision of Teide and Pico Viejo hydrothermal systems in three zones: summit crater, upper and lower hydrothermal systems. Self-potential maxima related to hydrothermal activity are absent from the proximal parts of the NE and NW rift zones as well as from at least two of the mafic historical eruptions (Chinyero and Siete Fuentes), indicating that long-lived hydrothermal systems have developed exclusively over relatively shallow felsic magma reser-voirs. Towards Las Cañadas caldera floor and walls, the influence of the central hydrothermal systems disappears and the self-potential signal is controlled by the topography, the distance to the water table of Las Cañadas aqui-fer and its geometry. Nevertheless, fossil or remanent hydrothermal activity at some points along the Caldera wall, especially around the Roques de García area, is also suggested by the data. Self-potential data indicate the existence of independent groundwater systems in the three calderas of Ucanca, Guajara and Diego Hernández, with a funnel shaped negative anomaly in the Diego Hernández caldera floor related to the subsurface topogra-phy of the caldera bottom. Two other important self-potential features are detected: positive values towards the northwestern Santiago rift, possibly due to the relatively high altitude of the water-table in this area; and a linear set of minima to the west of Pico Viejo, aligned with the northwestern rift and related to meteoric water infiltra-tion along its fracture system.

Raman–Mössbauer–XRD studies of selected samples from “Los Azulejos” outcrop: A possible analogue for assessing the alteration processes on Mars

“…1). From the geochemical point of view, the Cañ adas edifice has been and is also affected by active hydrothermal and fumaloric activities as well as CO 2 diffuse emission (Villasante-Marcos et al, 2014), this has acted after the Caldera formation. The combination of the mechanical and geochemical processes produced a heterogeneous volcanic system, where really interesting specific outcrops could become a terrestrial analogues for instrument testing and contribute to the science development of new space missions.…”

Recognizing and tracking volcanic hazards related to non-magmatic unrest: a review

“…Nevertheless, changes in the water saturation state in a volcanic edifice can drastically change its mechanical and hydraulic conditions (Reid 2004). These variations in hydraulic regime in a volcano can be detected through self potential, microgravity, resistivity or VLF surveys (Finizola et al 2003;Révil et al 2004;Zlotnicki et al 2006;Gottsmann et al 2007;Fournier et al 2009;Villasante-Marcos et al 2014). Water level gauging in wells or flow rate measurements from (thermal) springs at volcano flanks is the most direct way, although few examples of frequent monitoring exist (Ingebritsen et al 2001;Hurwitz et al 2002;Taran and Peiffer 2009), which inevitably leads to the need for numerical modeling procedures to increase theoretical insights (Hurwitz et al 2003;Todesco and Berrino 2005).…”

Aquifer Recharge Estimation through Atmospheric Chloride Mass Balance at Las Cañadas Caldera, Tenerife, Canary Islands, Spain

“…The hydrogeological behaviour of the high-permeability TPVC deposits contrasts with the low-permeability Las Cañadas Edifice bedrock, the hydrothermal alteration core below TPVC, and the dyke-intrusion network across them [31,32] (Figure 2). Low-permeability materials act as barriers to the groundwater flow, thus allowing the groundwater storage in the high-permeability summit caldera above 1800 m a.s.l.…”

“…Low-permeability materials act as barriers to the groundwater flow, thus allowing the groundwater storage in the high-permeability summit caldera above 1800 m a.s.l. [30,32,33] (Figure 2). The existence of a low-permeability clay-rich debrisavalanche deposit at the IGV bottom related to the landslide origin of this valley [24,31,34,35] enhances the relatively fast groundwater flow along this valley from TPVC and LCC to the northern coast ( Figure 2).…”

“…The water-table geometry was inferred from self-potential and audiomagnetotelluric data [32]. Data showed two main eastern and central-western groundwater systems divided by the collapse caldera limit with different water-table trends, as recorded by CIATFE in scientific boreholes S-1 and S-2, respectively [30,45].…”