Caldera De Research Articles

The Canaries: an important biogeographical meeting place

The Canaries: an important biogeographical meeting place

Tachinidae (Diptera) from the Caldera de Taburiente National Park, La Palma (Canary Islands)

Data on distribution, abundance and phenology of Tachinidae (Diptera) from the Caldera de Taburiente National Park on La Palma are given, based on systematic Malaise trap and yellow pan trap samples between August 1999 and July 2001. The occurrence of 22 species is proved; all of them were already known from the Canary Islands, but two species ( Gonia quadrisetosa and Phytomyptera vaccinii ) are recorded from La Palma for the first time. The present paper is a result of the project “Inventory and study of the invertebrate fauna of the Caldera de Taburiente National Park”.

A new species of Tardigrada (Eutardigrada: Macrobiotidae) from Iberian Peninsula and Canary Islands (Spain)

Minibiotus gumersindoi n. sp. is described. This species was collected on a granite mountain range in Sierra de Guadarrama (Bustarviejo valley, Embalse de la Jarosa and Cercedilla, Madrid, Spain) and on a volcanic island in Parque Natural Caldera de Taburiente (La Palma, Canary Islands, Spain). This new species is characterized by a unique set of characters in the genus: the presence of large round pores in the body and a larger round pore at the distal part of each leg. New records of several known species, for Madrid, Canary Islands and/or the Iberian Peninsula are given.

Inventariando la biodiversidad en el Parque Nacional de La Caldera de Taburiente (La Palma, Islas Canarias, España): novedades científicas

This paper is the first result of an agreement between the Organismo Autonomo Parques Nacionales and the Consejo Superior de Investigaciones Cientificas, entitled “Inventory and study of the Invertebrate Fauna of the National Park of La Caldera de Taburiente”. A detailed account of the faunistic novelties found up to now among the specimens of terrestrial and freshwater invertebrates collected along the two years of sampling (July 1999 to July 2001), whose number is estimated in ca. 500,000, is given. A brief description of planning and of methodology applied to the inventory of the invertebrate fauna is made and a tabulated summary of novelties is presented. The list shows at present 284 families, 594 genera and 739 species. For the Canary Islands, the present record of new taxa is 29 families, 115 genera (1 of them confirmed as new to Science and 3 awaiting confirmation) and 187 species (24 new to Science). Moreover, 242 genera and 338 species are new to the fauna of La Palma I., being known from other islands of the archipelago. Other 47 taxa, still being studied, could be new to Science as well. These results have been reached with the study of just a minimal part of the whole material, which underlines the need for systematic, continued sampling to evaluate the faunistic richness of poorly explored areas and its possible necessity for protection. Therefore, one should expect more novelties and the inventory may increase significantly when all the material is revised.

Nature and origin of toreva remnants and volcaniclastics from La Palma, Canary Islands

New data pertaining to the origin of volcaniclastic fan delta deposits (the El Time group) and previously unreported toreva remnants (intact landslide blocks) are presented in terms of their relationships with the Quaternary flank destruction of Bejenado volcano on La Palma, Canary Islands. Bejenado volcano is the heavily dismantled relic of a stratocone which developed at the confluence of the Cumbre Nueva embayment and the Caldera de Taburiente collapse amphitheatre. Both of these giant landslide structures formed at around 0.55 Ma after ∼0.2 Ma of gravitational spreading on the western and eastern flanks of the Taburiente–Cumbre Nueva shield volcanic complex. Evidence is presented on the basis of stratigraphic, photogeologic and Geographic Information System studies that both the toreva remnants and the El Time group can be related to the sequential collapses of the north flank and summit region of Bejenado inside the Caldera de Taburiente and the northernmost part of the adjoining Cumbre Nueva embayment. The collapses probably occurred between 0.44 and 0.4 Ma and they involved a volume of around 5 km 3. The toreva remnants display a deformed volcanic architecture, traversed by discontinuities which developed during impact and post-collapse dislocation during slip. They are composed of layer-differentiated scoria with ancillary ankaramite and basanite–tephrite lavas and occasional dikes. They rest upon a thin veneer of sheared volcaniclastic deposits in relative proximity to the disfigured north flank of Bejenado. The collapse event(s) is distinguished by its extremely low mobility due to the deceleration of the debris avalanche mass within the confines of the Caldera de Taburiente. The high friction coefficient ( H/ L=0.22) reflects this topographic factor. Reworking of the avalanche matrix gave rise to the accumulation and offshore progradation of the fan delta deposits at the SW base of Bejenado. Contemporaneous fluvial sediments, sourced by the retrogressive erosion of the pre-Bejenado collapse scarps, were fed into the subaerial confines of the Cumbre Nueva embayment. Piecemeal scarp failure and the extrusion of substratum from beneath the scarps also contributed to the sediment budget. The fluvial sedimentation rates subsequently increased with the onset of Cumbre Vieja volcanism prior to 0.125 Ma. These processes have contributed to the development of the flat-floored submarine channels which extend onto the volcaniclastic apron west of La Palma. These new data give a fresh insight into the role of epiclastic processes, landsliding and volcanism in the morphology and sediment mass balance of an oceanic island volcano system.

Geología y vulcanología de La Palma y El Hierro, Canarias Occidentales

Geología y vulcanología de La Palma y El Hierro, Canarias Occidentales

Formation d'une caldera d'érosion et instabilité récurrente d'une île de point chaud : la caldera de Taburiente, La Palma, îles Canaries / Formation of an erosion caldera and recurring instability on a hotspot-generated island: the caldera de Taburiente, La Palma, Canary Islands

Abstract The caldera de Taburiente is an erosion caldera caused by backwearing of the walls of a giant landslide embayment that affected the south-west flanks of the island of La Palma 560 ky. ago. This study reconstitutes the geonwrphological evolution of the depression and emphasises the role of lithological and structural factors. Patterns of erosion are guided by the structural configuration, in which uplifted and deeply weathered submarine volcanic materials are overlain by denser subaerial volcanic rocks, and by the geometry of a deep-seated structure, which has been interpreted as an older central collapse caldera. Recurrent instability is a determining factor in the formation of erosion calderas on hotspot-related islands. The construction rates (0,5-2 m/ka) and destruction rates (linear incision: 0,3-3,5 m/ka; headward erosion: 0,7-20 m/ka) estimated in this study provide a time-frame for understanding the stages of growth and decay of volcanic landforms in the Canary Islands.

Comparative avian biodiversity of five mountains in northern Cameroon and Bioko

Larison, B., Smith, T.B., Fotso, R. & McNiven, D. 2000. Comparative avian biodiversity of five mountains in northem Cameroon and Bioko. Ostrich 71 (1 & 2): 269–276. Endemism among birds is widespread in the montane forests of western Cameroon and the Gulf of Guinea. The region includes some of the rarest and most threatened species in Africa. We conducted avian surveys of four previously unsurveyed montane sites in northern Cameroon, including Mt. Ngang-Ha, Hoséré Vokré, Tchabal Gandaba, and Tchabal Mbabo, as well as the northern slope of Caldera de Luba on the island of Bioko, Equatorial Guinea. We report here on avian species richness and relative abundance, and evaluate the conservation potential of each site based on avifaunal richness. The montane forest on both Tchabal Mbabo and Caldera de Luba is extensive, while on the other mountains, the vegetation is not characteristic of montane forest, and consists primarily of small gallery forests embedded in savanna. Tchabal Mbabo and Caldera de Luba had the greatest species richness and abundance of montane birds, while Tchabal Gandaba had the greatest overall avian species richness and abundance. Few montane species were noted on Mt. Ngang-Ha and Hosere Vokre, and avian abundance was quite low on both mountains. Of the mountains surveyed, Tchabal Mbabo and Caldera de Luba exhibit the greatest potential for conservation based on extent of montane forest, and montane species richness and abundance.

Recurrent large‐scale landsliding on the west flank of La Palma, Canary Islands

A large area of debris avalanche deposits has been discovered on the western submarine flanks of the island of La Palma. Multibeam bathymetry and its derivative backscatter data, Towed Ocean Bottom Instrument (TOBI) sidescan sonar images, and 3.5 kHz and airgun seismic reflection data have been used to identify at least two, and possibly as many as four, major landslide events. The youngest of the events, the Cumbre Nueva Debris Avalanche, extends onshore into the valleys bounded by the Caldera de Taburiente and Cumbre Nueva Ridge, which mark the degraded collapse scars. Radiometric dating of the volcanic flows in the headwall indicate an age of between 536 and 125 ka for this landslide. The debris avalanche covers an area of 780 km2, has a maximum thickness of 500 m, and has an estimated volume of 95 km3. Older deposits, collectively referred to as the Playa de la Veta Debris Avalanche Complex, are probably, as the name indicates, an amalgamation of at least two or three events rather than the result of a single catastrophic failure. The Playa de la Veta Debris Avalanche Complex is associated onshore with an unconformity dated as late Matuyama (1 Ma to 800 ka). It covers an area of 1200 km2, has a maximum thickness of 1300 m, and may represent a total volume of up to 650 km3. The greater thicknesses and limited areas occupied by debris avalanches on the western flank of La Palma, compared to other landslides in the Canary Archipelago, suggest that the La Palma landslide masses have relatively low mobility. The different debris avalanche lobes formed by each landslide event are separated by channels 2–2.5 km wide. The clear relationship between channel position and the boundaries of each debris avalanche lobe indicates that debris avalanches control later channel formation and pathways. The relief of the submarine flanks of the La Palma volcanoes, in the areas of island slope unaffected by landslides, is mainly the result of constructional volcanic processes. However, the older submarine slopes, such as in the northern Taburiente volcano, may also have been modified by smaller‐scale submarine mass wasting and sediment flows.

Later stages of volcanic evolution of La Palma, Canary Islands: Rift evolution, giant landslides, and the genesis of the Caldera de Taburiente

Research Article| May 01, 1999 Later stages of volcanic evolution of La Palma, Canary Islands: Rift evolution, giant landslides, and the genesis of the Caldera de Taburiente Juan Carlos Carracedo; Juan Carlos Carracedo 1Estación Volcanológica de Canarias, IPNA-CSIC, P.O. Box 195, 38206, La Laguna, Tenerife, Spain2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom Search for other works by this author on: GSW Google Scholar Simon J. Day; Simon J. Day 2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom3Greig Fester Centre for Hazards Research, University College London, WCIE GBT United Kingdom Search for other works by this author on: GSW Google Scholar Hervé Guillou; Hervé Guillou 4Laboratoire des Sciences du Climat et de l'Environnement, CNRS-CEA, F-91198 Gif-sur-Yvette, France Search for other works by this author on: GSW Google Scholar Philip Gravestock Philip Gravestock 2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom Search for other works by this author on: GSW Google Scholar Author and Article Information Juan Carlos Carracedo 1Estación Volcanológica de Canarias, IPNA-CSIC, P.O. Box 195, 38206, La Laguna, Tenerife, Spain2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom Simon J. Day 2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom3Greig Fester Centre for Hazards Research, University College London, WCIE GBT United Kingdom Hervé Guillou 4Laboratoire des Sciences du Climat et de l'Environnement, CNRS-CEA, F-91198 Gif-sur-Yvette, France Philip Gravestock 2Department of Geography and Geology, Cheltenham and Gloucester College of Higher Education, United Kingdom Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1999) 111 (5): 755–768. https://doi.org/10.1130/0016-7606(1999)111<0755:LSOVEO>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Juan Carlos Carracedo, Simon J. Day, Hervé Guillou, Philip Gravestock; Later stages of volcanic evolution of La Palma, Canary Islands: Rift evolution, giant landslides, and the genesis of the Caldera de Taburiente. GSA Bulletin 1999;; 111 (5): 755–768. doi: https://doi.org/10.1130/0016-7606(1999)111<0755:LSOVEO>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The islands of La Palma and El Hierro form the western end of the hotspot-induced Canary Islands chain. Both islands are at present in the earliest and fastest shield-building stage of growth and show many similarities with the Hawaiian Islands. La Palma shows two very distinct phases of volcanic construction: (1) a Pliocene submarine volcanic and intrusive series, interpreted as an uplifted seamount at least 1500 m above present sea level, and (2) a subaerial volcanic series erupted in the past 2 m.y. Taburiente volcano initially formed the northern part of the island and then extended to the south, forming a ridge (Cumbre Nueva Ridge) that was partially destroyed about 560 ka by a giant lateral collapse (the Cumbre Nueva collapse), possibly involving 180–200 km3 of subaerial volcanic material. The northwest boundary of the Cumbre Nueva collapse formed a vertical scarp that, enlarged by headward erosion, formed the spectacular depression of Caldera de Taburiente. Cumbre Vieja volcano, a north-south elongated rift, forms the southern half of La Palma and constitutes its last stage of growth, including all eruptive activity in the past 125 k.y. Detailed field observations, mapping, and high-precision radiometric dating have allowed reconstruction of the growth and structural changes of the Cumbre Vieja volcano. Interactions between eruption rates, coastal erosion, and glacio-eustatic sea level change allow stratigraphic subdivision of the edifice. The structure of the volcano has been controlled for most of its history by a rift system with a clearly dominant north-south and less-distinct north-east and north-west volcanic rift zones. The rift reorganization of the volcano to a single north-south rift since 7 ka and the opening of faults during the 1949 eruption probably reflect increasing instability of the west flank of the volcano. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Geological excursion guide 10: The volcanic geology of La Palma, Canary Islands

The island of La Palma in the Canary Islands provides an excellent opportunity to examine the products of basaltic volcanism. In contrast to Tenerife, the volcanic activity of La Palma has been more effusive, and the island has largely escaped the impact of package tourism. The scenery is impressive, in particular the classic Caldera de Taburiente.

Constructive and destructive episodes in the building of a young Oceanic Island, La Palma, Canary Islands, and genesis of the Caldera de Taburiente

The results of new field observations, 23 new KAr determinations and sixteen previously published determinations provide the basis for the reconstruction of the subaerial volcanic history of the island of La Palma, after the seamount activity represented by the materials of the Basal Complex. An eruptive phase between 2.0 and 1.3 Ma formed a large shield. A period of volcanic quiescence followed, until around 1 Ma, during which a large lateral collapse partly destroyed the former edifice. Between 1.05 and 0.7 Ma, activity was renewed in the shield and a N-S ridge was built in the southern part of the island. Around 0.7 Ma, two new large lateral collapses affected the western part of both edifices, and they were followed by eruptions between 0.71 and 0.65 Ma which built a new edifice that partly filled the depressions thus created. The Caldera de Taburiente constitutes the eroded remnants of the depression formed in the northern shield. From 0.65 Ma to present, activity has been restricted to the N-S ridge, which has continued to grow southwards. There was a general N-S migration of volcanic activity with time, but in the shield the trend was northwest to southeast. Eruptive rates seem to have been fairly constant during the different eruptive phases considered, between 0.15 and 0.37 km 3/ka. A very similar succession of constructive and destructive episodes has been obtained for the neighboring island of Hierro, but in this case the activity started around 0.8 Ma and eruptive rates were about 0.5 km 3/ka.

The history of intrusive activity on the island of La Palma (Canary Islands)

Abstract The island of La Palma, located in the northwest of the Canary archipelago, consists of two main geological units. (1) The subaerial extrusive Coberta Series covers most of the island and consists of alkali basaltic lavas, phonolitic plugs, and pyroclastic rocks, erupted between 1.61 Ma and the Recent. (2) The basement complex is exposed in the Barranco de Las Angustias and the Caldera de Taburiente and consists of the submarine intrusive and extrusive Seamount Series and a basal plutonic complex. Alkali basaltic dikes of different ages and orientations intruded in both units. Three groups of dikes and sills can be distinguished, based on their field relationships, petrography, geochemistry and ages. The oldest Group I, represent the feeder dikes to the Seamount Series, intruded between 2.9 and 4.0 Ma B.P. They were originally steep, with a N05°W strike and perpendicular to the originally nearly flat bedding of the layered Seamount Series. Subsequent to emplacement, Group I dikes and the extrusives of the Seamount Series were rotated into their present orientation. Group II sills, intruded parallel to the bedding of the Seamount Series ( 45 230 ), are coeval with or younger than Group I, but older than the erosional unconformity separating the Coberta and the basement complex (i.e. > 1.6 Ma; 50 vol % of the volcanic edifice of the La Palma seamount and highlight the importance of intrusive processes for island growth. Intrusions into central oceanic volcanoes like La Palma may result in an uplift, and rotation of more than 30 km 3 by up to 45°.

A New Species of Cicer (Leguminosae: Papilionoideae) from the Canary Islands

riente, La Palma by the late E. Sventenius accompanied by the first author. Due to the strikingly Vicia-like foliage of the plant it was initially thought to belong to that genus and was tentatively treated as an undescribed species of Vicia (Santos Guerra 1983). However, detailed studies of flowers, fruits and seeds by both authors have demonstrated that the plant is, without doubt, a new species of Cicer.f Prior to a botanical expedition to the Canary Islands in 1982, Miss Susyn Andrews found at Kew an unmounted specimen of this new plant collected on La Palma by R. J. Andrews in 1960. This appears to be the earliest collection of the species. Since 1972 it has been found in the pine forests of Garafia and at other locations within the Caldera de Taburiente but reports of it growing near El Cabrito (Mazo) have not been confirmed. In 1983 A.S.G. also collected the plant on the island of Tenerife. With some adjustments, Van der Maesen (1972) bases his classification of the genus Cicer on Linczveski's (1948) concept of Popov's (1929) system and places the type species, C. arietinum L. in subgenus Pseudononis, section Monocicer, series Arietina. This placement is nomenclaturally incorrect as following Article 22.1 of the International Code of Botanical Nomenclature (1983) 'the name of any subdivision of a genus that includes the type of the adopted, legitimate name of the genus to which it is assigned is to repeat that generic name unaltered as an epithet... .'. Thus series Arietina should be replaced by series Cicer, section Monocicer by section Cicer and subgenus Pseudononis by subgenus Cicer. This necessary nomenclatural change is, however, incidental to the placing of the new species as it clearly cannot be comfortably placed, taxonomically, in either of the two subgenera recognised by Van der Maesen having flower size and calyx characteristics intermediate between the two. The combination of characteristics of this remarkable species distinguishes it from all other known species of Cicer and it has no obvious affinities with any of the taxa dealt with by Van der Maesen. After only slight hesitation we here propose a new subgenus of Cicer in which to place the new species.

Evolution of La Palma, Canary archipelago

La Palma is the northwestern island in the Canary archipelago. The island is volcanically active and in recent years there have been two eruptions (1949 and 1971). The oldest rocks that crop out on the island are altered spilitic lavas and they are intruded by numerous dykes and a number of mafic and ultramafic plutonic rocks. These rocks form part of the floor of the huge Caldera de Taburiente. In the walls of the Caldera one finds a 1000 metres thick unit that is composed of lavas and tephra. The rocks are called the El Time formation; and they together with the rocks of the Cumbre Vieja ridge are mainly composed of accumulative mafic rocks, basanites, hawaiites, benmoreites and phonolitic trachytes. These sodarich alkalic rocks are considered to have evolved by fractional crystallization of a basanitic magma in a near surface environment. It is proposed that La Palma developed on a relatively cold section of a plate of oceanic lithosphere that was over 100 m.y. old. During the Alpine-Atlas orogeny this section of the African plate was disrupted and a basanitic magma was extruded onto the sea floor. The volcanic focus of this eruption became established as a local centre for the degassing of the mantle and as a result this area has experienced a long series of eruptions. During the first phase in the evolution of La Palma the submarine edifice of the island was constructed and the rocks of the Caldera Floor formation were emplaced. After a period of marine erosion the huge old volcano Taburiente developed in the northern half of the island. During the final phase in the evolution of the island the southern section of the volcanic edifice subsided and formed the El Paso tectonic basin and the volcanic rift zone along which the many smaller volcanoes of the Cumbre Vieja ridge have developed.

San Miguel de La Palma — A volcanic island in section

San Miguel de La Palma is the northwestern island in the Canary group. An extensive vertical section through the island can be seen in the deep Caldera de Taburiente in the north of the island. The island in divided into four units: (1) the floor of the Caldera de Taburiente, (2) the remainder of the old volcano Tuburiente (El Time formation), (3) the El Paso tectonic basin, and (4) the Cumbre Vieja mountain land that forms the southern part of the island. The Caldera Floor formation consists of (1) a variety of deformed metamorphosed and metasomatised basaltic and trachytic rocks, (2) metamorphosed pyroclasts, and (3) bodies of gabbro, troctolite, wehrlite, dunite, alkalic gabbro and essexite. These rocks are cut by mafic and bostonitic dykes. The lavas and pyroclasts of the El Time formation overlie the Caldera Floor formation and generally dip outwards and away from the caldera. Alkalic basalts are the main lava type, followed by trachybasalts with lesser amounts of trachyandesite, trachyte and phonolite. The El Paso tectonic basin is a subsided segment of the volcano Tuburiente, and consists mainly of El Time formation rocks. All the major recorded eruptions have issued from the Cumbre Vieja mountain land. The eruptive products found in the mountain land range from alkalic basalt to phonolite. Pyroclasts and phonolitic lavas are more common than in the earlier formations. Tall spires of hauyne phonolite are found in a number of localities. The eruptive products now found on La Palma are believed to have developed from an alkaline basalt magma. Under normal circumstances this magma rose rapidly from the upper mantle, and erupted; however, when the La Palma volcanic edifice was large enough to accommodate a magma chamber differentiation took place; silica was removed, and both ultramafic cumulates, and trachytic and phonolitic differentiates were produced.