The Holocene volcanic history of Gran Canaria island: implications for volcanic hazards

Abstract

Previous published data, combined with our results of 13 new radiocarbon ages and extensive geological fieldwork, indicate that during the past 11 ka 24 monogenetic basaltic eruptions occurred in the north sector of Gran Canaria. These eruptions can be grouped into three periods of eruptive activity: 1900-3200 14 C a BP; 5700-6000 14 C a BP; and an older period represented by only one eruption, El Draguillo, dated at 10 610 AE 190 14 C a BP. Archaeological studies have shown that the more recent eruptions affected prehistoric human settlements on the island. Field studies demonstrate that the eruptions typically built strombolian cones (30-250 m in height) and associated relatively long lava flows (100-10 350 m in length); a few eruptions also produced tephra fall deposits. The total erupted volume of these eruptions is about 0.388 km 3 (46.1% as tephra fall, 41.8% as cinder cone deposits and 12.1% as lava flows). The relatively low eruption rate ($0.04 km 3 ka À1 ) during the past 11 ka is consistent with Gran Canaria's stage of evolution in the regional volcano-tectonic setting of the Canary Archipelago. The results of our study were used to construct a volcanic hazards map that clearly delimits two sectors in the NE sector of Gran Canaria, where potential future eruptions would pose a substantial risk for densely populated areas.

The Azuaje travertine: an example of aragonite deposition in a recent volcanic setting, N Gran Canaria Island, Spain

“…One of these Holocene volcanic events generated an eruptive fissure located at the NE flank of the Pleistocene Montana Doramas cone, from which a lava channel flowed more than 6 km along the bottom of the Azuaje Gorge in the NE of the island. This eruption has been radiocarbon dated at 2420 ± 40 years BP (Rodriguez-Gonzalez et al, 2009).…”

“…Outcrop 2 consists of filled fractures and well-laminated deposits only a few meters from the present river. Part of the outcrop covers materials from a lava bubble produced during the flow and subsequent cooling of the Holocene lava (Rodriguez-Gonzalez et al, 2009). Outcrop 3 is further upstream than the other outcrops, on the left side of the stream.…”

“…Their position over a lava-flow erupted about 2500 years ago indicates that the carbonate deposits are very recent. There may have been a relationship between the volcanic event and carbonate deposition, as recorded in the smaller Berrazales deposit, which lies within a valley with Holocene volcanic activity dated at about 3 kyr (Rodriguez-Gonzalez et al, 2009). However, there is no active carbonate deposition in either of these two areas and the recent spring activity has been strongly reduced in the last decades (Hemandez-Quesada et al, 2011).…”

Factors controlling the morphology of monogenetic basaltic volcanoes: The Holocene volcanism of Gran Canaria (Canary Islands, Spain)

“…1) (Perez-Torrado et al, 1995;Carracedo et al, 2002;Guillou et al, 2004). The most recent PostRoque Nublo volcanism, Holocene in age, created a monogenetic volcanic field with 24 identified single volcanic eruptions (Rodriguez-Gonzalez, 2009;Rodriguez-Gonzalez et al, 2009). This Holocene volcanic activity was restricted geographically to the geologically young quadrants of the island.…”

Estimación del comportamiento futuro del nivel del mar en las Islas Canarias a partir del análisis de registros recientes

“…De acuerdo con este modelo más aceptado, las islas centrales se encontrarían en un período de estabilidad tectónica (Rodríguez-González et al, 2009), mientras que las más occidentales (principalmente El Hierro) están aún experimentando un ligero ascenso tectónico, además de fenómenos de magmatismo reciente . En las islas orientales se observa un fenómeno de ligera subsidencia, al tratarse de islas más antiguas .…”