Abstract
This work provides geological observations that support the existence of several large rock slides in the northwest sector of the Gran Canaria Island, which are now covered by recent lavas. Some erosional forms has been identified: a paleo-relief developed in Pliocene volcanic materials which could be related to a large rock slide, a number of streams with strong incision and sharp diversions which are related to the flanks of the fractured rock mass, a clear topographical unconformity between the oldest erosion surfaces, as well as a prior secondary scarp near de coastal border. Moreover, we have identified some aggradational morphologies: a debris avalanche deposit covering the offshore area of the island, several scoria cones which are developed following the main scarp of the rock slide and a field of volcanoes which covers the foot of the slide in the onshore part of the island. These observations confirm the existence of some large rock slides that affect successively the NW flank of Gran Canaria during the Miocene to Pliocene. These flank instabilities suggest a NE-SW extensional regime, which could be related to a NW-SE fault zone that divides the island into two sectors. This hypothesis is in agreement with the spreading process which has been proposed for other volcanic islands.
Access provided by Autonomous University of Puebla. Download chapter PDF
Similar content being viewed by others
Keywords
Introduction
Gran Canaria is a circular volcanic island dating back more than 14.5 Ma, but eruptions have continued until very recent time. The geological evolution of the Gran Canaria comprises four main volcanic stages, alternating with periods of erosion (Balcells et al. 1992; Carracedo et al. 2002; Ancochea et al. 2004; Guillou et al. 2004; Pérez Torrado 2008; Schmincke and Sumita 2010). The first volcanic stage of the island was built during the Miocene (14.5–7.3 Ma) by a shield volcano of basic composition, which developed later a kilometric caldera collapse in the central part of the island. Two generations of superimposed stratovolcanoes were developed inside the caldera: Tejeda and Roque Nublo volcanoes. The Tejeda Volcano was related to the Miocene activity (Cycle I), but had a salic composition (rhyolitic to trachyphonolitic). The Roque Nublo Volcano was developed during the Pliocene (5.6–2.9 Ma) forming the basic to salic deposits of the Roque Nublo Cycle. The Plio-Quaternary activity of the last two stages is mainly related to fissure eruptions of basaltic composition (Post-Roque Nublo and Recent Cycles). This last activity developed a number of fields of cinder cones and their lavas, which have been related to a NW-SE rifting.
Several intensive erosive stages have been developed between the main volcanic cycles. The most significant flank collapses and large rock slides of Gran Canaria have been triggered in relation to these periods of erosion, in particular, at the final phases of the Miocene shield volcano (~ 9 Ma) and the end of Roque Nublo Cycle (3.5–2.9 Ma) (Funck and Schmincke 1998; Mehl and Schmincke 1999; Yepes et al. 2011). The oldest evidence of flank instability has been related to breccias levels which are found in discordant contact between the lavas of the Miocene shield volcano, located in the southwestern sector of the island (Schmincke 1993; Schmincke and Sumita 2010). Other evidence of this phenomenon would be the coastal morphology in arc extending between La Aldea and Agaete villages, in the western sector of the island (Coello and Coello 1999). This coast defines a deep coastal cliff that has some collapsed rock masses on his foot (Criado et al. 1998) and seems to involve the volcanic materials that define the western border of the Tejeda caldera (Yepes et al. 2011). Our research has been also motivated by the anomalous distribution of lithologies of the different volcanic cycles in the field, in particular the location of the deposits of the Roque Nublo Cycle in the southern and northern sectors of the island. These observations have been considered as evidence of two large flank collapses: one that took place in the Roque Nublo stratovolcano at the end of the Roque Nublo Cycle (García Cacho et al. 1994; Pérez Torrado et al. 1995), and another that would have occurred in the northeastern sector of the island (Hansen 2009). Finally, additional evidences of flank instabilities have been described in the offshore sector of the island. The anomalous topography found in this sector has been interpreted as submarine deposits of debris avalanches and debris flows, which can cover wide areas of the sea floor, related to large flank collapses (Funck and Schmincke 1998; Krastel et al. 2001; Acosta et al. 2003).
This paper provides geological and geomorphologic observations that support the existence of flank instabilities in the northwest sector of the Gran Canaria, in a circular sector of about 175 km2, which could be defined between the Agaete, Arucas and Cruz de Tejeda villages (Fig. 1).
The geomorphological observations are focused on the analysis of the drainage system, scarps, erosion surfaces, residual reliefs, cinder cones and offshore debris avalanche deposits. The geologic evidence is derived from the lithological relationships between the surface geology and 71 lithological columns that reach depths between 20 and 460 m (Fig. 4, Table 1). The surface data were derived from geological maps (Balcells et al. 1986; Barrera and Gómez 1986; Balcells and Barrera 1987a, b; Balcells et al. 1992), whereas the underground data were obtained from the wells and boreholes reported in Galindo et al. (2011). The descriptions of the lithological columns (Table 1) were obtained from the database of boreholes developed by the Geological Survey of Spain (Instituto Geológico y Minero de España, IGME) during different research projects.
Geomorphological Observations
The drainage system is centrifugal and it is modified by sharp river diversions with a NW-SE trend. These diversions seem to be related to the main NW-SE trend of the feeding dykes of the Post-Roque Nublo Cycle, conditioning the differential erosion of the substrate. These small anomalies in the drainage system would be a morphological expression of the NW-SE extension that would have undergone on Gran Canaria during the Post-Roque Nublo Cycle. The streams with the steepest slopes are located on the lateral edges of the study area (Agaete and Guía). At least one embedded stream that describes very sharp changes in its path can be recognized in both margins. The Berrazales (or Agaete) Ravine would be the most typical case in the western sector, and the San Andrés and Moya ravines in the eastern sector. These streams increase sharply their relative divergence close to the populations of Fontanales and Fagagesto, defining a wide circular sector of the island with a relief organization which is uncorrelated laterally with the geomorphology observed in the surrounding areas. These observations suggest that these streams with a variable path have been fitted in favour of very penetrative planes of weakness in the rock mass. These planes could be related to the lateral flanks of a large rock slide. This phenomenon is also observed at a small scale in the area between Agaete and Gáldar, coinciding with a morphostructural scarp (S5). In addition, at the base of this scarp, a number of rock slide deposits have been recognized (Fig. 2).
In the coastal zone, most of the ravines are interrupted or deviated by a wide flat-bottomed valley with a NW-SE trend and a few isolated cinder cones (Gáldar, Gallinero and Montaña Clavijo) of the Recent Cycle (Fig. 3). The peripheral location of this small volcanic field could be in agreement with lithostatic unloading related to the foot area of a slipped mass. These observations suggest that the occurrence of the flank instabilities in Gran Canaria could be extended during the Post-Roque Nublo Cycle. In addition, the head area is disconnected from the summit of the island by a number of cinder cones of the Recent Cycle (e.g. Pinos de Gáldar, Juncalillo and Montañón Negro). This observation suggests the existence of a lateral spreading due to the intrusion of dykes during the Post-Nublo Roque and Recent cycles, a process that has already been described in other volcanic islands (McGuire et al. 1990; Elsworth and Voight 1995; Voight and Elsworth 1997; Day et al. 1999; Galindo 2005; Cecchi et al. 2005; Del Potro and Hürlimann 2007). The process of intrusion of dykes took place until the end of the Cycle I, a period in which the orientation of the stress field related to volcanism changed: from a radial pattern change to a NW-SE fissural regime (Yepes et al. 2011). In addition, the lateral spreading would be amplified by the age of the island, as it would provide a longer period to increase the weight of the volcano and, subsequently, to produce an unstable condition as other authors has been proposed in similar volcanic areas (Lo Giudice and Rasa 1992; Clague and Denlinger 1994; Van Wyk de Vries and Francis 1997; Borgia et al. 2000; Reid et al. 2001).
The relief inflections allow distinguishing remnants of four different erosional surfaces (S0, S2, S4 and S6) (Figs. 2 and 3). The older structural surface (S0), defined by the lava flows of the Phonolitic Formation (Cycle I), can be related to a surface of summits where the lava flows of the subsequent volcanic stages (Roque Nublo, Post-Roque Nublo and Recent cycles) have been gradually embedded. Hence, the most recent surface (S6) defines the most embedded reliefs in the NW sector of the island. We have noticed a temporal alternation between these erosion surfaces and the stratigraphic unconformities (S1, S3 and S5), which are recognized later with lithological cross sections and interpreted as the sliding surfaces. This alternation of forms and processes support the hypothesis of large island flank instability along several volcanic cycles. This idea would be compatible with the existence of one or more translational rock slides with a very slow rate of movement. Triggering factors for this type of instability would be very old, reducing their energy. This fact suggests three remarks: (a) the recent processes of erosion could be able to generate new morphologies but not to remove the inherited forms, (b) the lava flows of the most recent cycles are embedded in the preexisting reliefs, and (c) the old sliding surfaces cover a greater extent than modern sliding surfaces.
The wide NE-SW valley is flanked by steep scarps, where old materials of the Cycle I outcrop (Figs. 3 and 4). These materials are difficult to correlate topographically with the surface of summits described above (S0) and, in addition, the southern scarp is covered by recent rock slides. These observations suggest that this valley could be the geomorphologic evidence of a secondary scarp (S5) that could be developed at the foot of a prior sliding mass (S3), resulting in a large rocky block (Montaña Almagro) disconnected of the main trend of the topography (Figs. 2 and 3). This hypothesis would be in agreement with the debris-avalanche deposits identified by other authors at the foot of the island shelf, between Agaete and Gáldar (Acosta et al. 2003).
Along the northern coast, there is a very steep escarpment with a height of several hundred meters. This relief has been interpreted as a result of a general tilt of the island to the south (Menéndez et al. 2008). However, the offshore investigations of the island shelf show the existence of several debris avalanche deposits close to Galdar (Acosta et al. 2003). Therefore, the complexity of the vertical movements experienced by the volcanic terrains indicates a polygenic character to the morphogenesis of the relief. The height of these coastal cliffs is compatible with the occurrence of an old flank slide and a later differential rising of a coastal block of the island.
Geological Investigations
Lithological cross-sections (Fig. 5) show sharp changes in the thickness of the formations of the Roque Nublo and Post-Roque Nublo cycles. The contact between the two formations suggests the existence of a paleo-relief compartmentalised in wide flat-bottomed valleys, separated by residual reliefs. This paleo-relief defines an erosion surface (S3) embedded between the remains of two previous structural surfaces: the top of the Roque Nublo Cycle (S2) and the surface of summits (S0).
The age of the paleorelief is implied by a recent structural surface (S4) which is defined by the lava flows of the Post-Roque Nublo Cycle of Pleistocene age. A thinning of the prior substratum, defined by the most recent materials of the Cycle I (Trachytic-Rhyolitic and Phonolitic formations), has been found below the paleo-relief described above (S3). This discontinuity (S1) confirms the occurrence of previous translational rock slides of Miocene to Pliocene age.
Discussion and Conclusions
The large flank instability found in the northwest sector of the Gran Canaria Island would be related to the intrusion of dykes during the end of the Cycle I and suggests a NE-SW extensional regime, which could be related to a central NW-SE fault zone that divides the island in two sectors: northeast and southwest. This stress regime seems to be established for an extended period of time, suggesting the coexistence of other triggering factors such as the lateral spreading of the volcanic edifice due to the combined effect of the weight of the volcano and the time. Moreover, the existences of two different lahar deposits (Las Palmas Detritic Formation) in the stratigraphic sequence of the island (Balcells et al. 1992) suggest the occurrence of highly explosive eruptions. The earthquakes related to these explosive periods could also be considered as a triggering factor of the large flank instabilities in Gran Canaria Island.
References
Acosta J, Uchupi E, Muñoz A, Herranz P, Palomo C, Ballesteros M, ZEE Working Group (2003) Geologic evolution of the Canarian Islands of Lanzarote, Fuerteventura, Gran Canaria and La Gomera and comparison of landslides at these islands with those at Tenerife, La Palma and El Hierro. Mar Geophys Res 24:1–40
Ancochea E, Barrera JL, Bellido F, Benito R, Brändle JL, Cebriá JM, Coello J, Cubas CR, De La Nuez J, Doblas M, Gómez JA, Hernán F, Herrera R, Huertas MJ, López-Ruiz J, Martí J, Muñoz M, Sagredo J (2004) Canarias y el vulcanismo neógeno peninsular. In: Vera JA (ed) Geología de España. IGME-SGE, Madrid, pp 637–671
Balcells R, Barrera JL, Gómez JA (1986) Mapa Geológico de España 1:25.000, hoja nº 1100 (Agaete). IGME, Madrid
Balcells R, Barrera JL (1987a) Mapa Geológico de España 1:25.000, hoja nº 1101 III-IV (Arucas). IGME, Madrid
Balcells R, Barrera JL (1987b) Mapa Geológico de España 1:25.000, hoja nº 1109 IV (Teror). IGME, Madrid
Balcells R, Barrera JL, Gómez Saínz JA, Hernán F, Schmincke H, Merlos A, Ruiz M, Brändle J, Meco J, Vidal Romaní JR (1992) Mapa Geológico de España 1:100.000, hoja nº 21-22 (Gran Canaria). IGME, Madrid
Barrera JL, Gómez JA (1986) Mapa Geológico de España 1:25.000, hoja nº 1108 I (Vecindad de Enfrente). IGME, Madrid
Borgia A, Delaney PT, Denlinger P (2000) Spreading volcanoes. Annu Rev Earth Pl Sci 28:359–570
Carracedo JC, Perez Torrado FJ, Ancochea E, Meco J, Hernan F, Cubas CR, Casillas R, Rodríguez-Badiola E, Ahijado A (2002) In: Gibbons W, Moreno T (eds) The geology of Spain. Geological Society, London, pp 439–472
Cecchi E, van Wyk de Vries B, Lavest J (2005) Flank spreading and collapse of weak-cored volcanoes. Bull Volcanol 67:72–91
Clague DA, Denlinger RP (1994) Role of olivine cumulates in destabilizing the flanks of Hawaiian volcanoes. Bull Volcanol 56:425–434
Coello Bravo JJ, Coello Bravo FJ (1999) El arco del Andén Verde, a big gravitational landslide in the northwestern coast of Gran Canaria (Canary Islands). Geogaceta 25:67–70
Criado C, Hansen A, Martín Artiles A (1998) Imbricación de procesos de vertiente, torrenciales y eólicos en el oeste de Gran Canaria: la génesis de la punta de las Arenas. In: Gómez Ortiz A, Salvador French F (eds) Investigaciones recientes de la Geomorfología española, Barcelona, pp 357–366
Day SJ, Carracedo JC, Guillou H, Gravestock P (1999) Recent structural evolution of the Cumbre Vieja volcano, La Palma, Canary Islands: volcanic rift zone reconfiguration as a precursor to volcano flank instability? J Volcanol Geoth Res 94:135–167
Del Potro R, Hürlimann M (2007) Strength of volcanic rock masses in edifice instability: insights from Teide, Tenerife. In: Malheiro AM, Nunes JC (eds) Volcanic rocks. Taylor & Francis, London, pp 175–183
Elsworth D, Voight B (1995) Dike intrusion as a trigger for large earthquakes and the failure of volcano flanks. J Volcanol Geoth Res 100:6005–6024
Funck T, Schmincke HU (1998) Growth and destruction of Gran Canaria deduced from seismic reflection and bathymetric data. J Geophys Res 103:15393–15407
Galindo I (2005) Estructura volcano-tectónica y emisión difusa de gases de Tenerife (islas Canarias), Ph.D. thesis, University of Barcelona, Spain, 398 pp
Galindo RE, Sánchez N, Benavides A, González Fernández I, Cruz T (2011) Estudio hidrogeológico de la zona norte de Gran Canaria. IGME, Madrid (in press)
García Cacho L, Díez-Gil JL, Araña V (1994) A large volcanic debris avalanche in the Pliocene Roque Nublo Stratovolcano, Gran Canaria, Canary Islands. J Volcanol Geoth Res 63:217–229
Guillou H, Pérez Torrado FJ, Hansen Machín AR, Carracedo JC, Gimeno D (2004) The plio-Quaternary evolution of Gran Canaria based on new K-Ar ages and magnetostratigraphy. J Volcanol Geoth Res 135:221–246
Hansen Machín A (2009) Volcanología y geomorfología de la etapa de rejuvenecimiento Plio-Pleistocena de Gran Canaria (Islas Canarias). Ph.D. thesis, University of Las Palmas de Gran Canaria, Spain (In edit)
Krastel S, Schminke HU, Jacobs CL, Rihm R, Le Bas TP, Alibés B (2001) Submarine landslides around the Canary Islands. J Geophys Res 106:3977–3997
Lo Giudice E, Rasa R (1992) Very shallow earthquakes and brittle deformation in active volcanic areas. The Etna region as an example. Tectonophysics 202:257–268
McGuire WJ, Pullen AD, Saunders SJ (1990) Recent dyke-induced large-scale block movement at Mount Etna and potential slope failure. Nature 343:357–359
Mehl KW, Schmincke HU (1999) Structure and emplacement of the Pliocene Roque Nublo debris avalanche deposit, Gran Canaria, Spain. J Vol Geoth Res 94:105–134
Menéndez I, Silva PG, Martín-Betancor M, Pérez Torrado FJ, Guillou H, Scaillet S (2008) Fluvial dissection, isostatic uplift, and geomorphological evolution of volcanic islands (Gran Canaria, Canary Islands, Spain). Geomorphology 102:189–203
Pérez Torrado FJ, Carracedo JC, Mangas J (1995) Geochronology and stratigraphy of the Roque Nublo Cycle, Gran Canaria, Canary Islands. J Geol Soc London 152:807–818
Pérez Torrado FJ (2008) Geología de Gran Canaria. Sociedad Geológica de España, Geo-Guías 5:27–39
Reid ME, Sisson TW, Brien DL (2001) Volcano collapse promoted by hydrothermal alteration and edifice shape. Mount Rainier, Washington. Geology 29:779–782
Schmincke HU (1993) Geological field guide of Gran Canaria. Pluto-Press, 227 pp
Schmincke HU, Sumita M (2010) Geological evolution of the Canary Islands. Görres-Verlag, 196 pp
Van Wyk de Vries B, Francis PW (1997) Catastrophic collapse at stratovolcanoes induced by gradual volcano spreading. Nature 387:387–390
Voight B, Elsworth D (1997) Failure of volcano slopes. Géotechnique 47:1–31
Yepes J, Rodríguez-Peces MJ, del Potro R (2011) Morphological evidence of a large collapse on the north-western flank of Gran Canaria (Canary Islands). Geophys Res, Abstracts 13, EGU2011-13060
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2013 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Temiño, J.Y., Sánchez, N., Rodríguez-Peces, M.J., Galindo, I., del Potro, R. (2013). Geomorphologic Evidences of Great Flank Collapses in the Northwest of Gran Canaria (Canary Islands, Spain). In: Margottini, C., Canuti, P., Sassa, K. (eds) Landslide Science and Practice. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-31313-4_10
Download citation
DOI: https://doi.org/10.1007/978-3-642-31313-4_10
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-31312-7
Online ISBN: 978-3-642-31313-4
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)