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Gibraltar Arc

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The Gibraltar Arc is a geological region corresponding to an arcuate orogen surrounding the Alboran Sea , between the Iberian Peninsula and Africa . It consists of the Betic Cordillera (south Spain), and the Rif (North Morocco). The Gibraltar Arc is located at the western end of the Mediterranean Alpine belt and formed during the Neogene due to convergence of the Eurasian and African plates.

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20-573: Maximum altitudes of the region are reached at the 3,482 m (11,424 ft) Mulhacén peak at the Cordillera Betica. Precipitation is collected mainly by the Guadalquivir (Betics) and Sebou (Rif) rivers, which have delivered most sedimentary infill of the homonym sedimentary foreland basins .. North–south convergence of the Eurasian and African plates occurred during the middle Oligocene to

40-606: Is a mountain range in the Andalusian province of Granada in Spain . It contains the highest point of continental Spain: Mulhacén , at 3,479 metres (11,414 ft) above sea level . It is a popular tourist destination, as its high peaks make skiing possible in one of Europe's most southerly ski resorts , in an area along the Mediterranean Sea predominantly known for its high temperatures and abundant sunshine. At its foothills

60-428: Is a ridge running broadly west-south-west - east-north-east. For a substantial distance, the watershed stays consistently above 3,000 metres (9,800 ft). This is sufficient altitude for the peaks to be consistently snow-covered. On the southern side of the range, several long, narrow river valleys lead off towards the south-west, separated by a number of subsidiary ridges. On the steeper and craggier northern side,

80-592: Is found the city of Granada , and a little further south, Almería and Motril . Parts of the range have been included in the Sierra Nevada National Park . The range has also been declared a biosphere reserve . The Sierra Nevada Observatory , the Calar Alto Observatory , and the IRAM 30m telescope are located on the northern slopes at an elevation of 2,800 metres (9,200 ft). The Sierra Nevada

100-468: Is located on the inner side of the arc, adjacent to the Alboran Sea, mostly consists of high-pressure, low-temperature metamorphic rocks . The External Zone, located on the outer side of the arc, is mostly made of sediments deposited on the passive margins of Africa and Iberia. These rocks became highly deformed during the westward emplacement of the hinterland of the subduction system, with some units in

120-415: Is not exceptionally dramatic in terms of steepness or local relief. The south flank of the mountain is gentle and presents no technical challenge, as is the case for the long west ridge. The shorter, somewhat steeper northeast ridge is slightly more technical. The north face of the mountain is much steeper and offers several routes involving moderately steep climbing on snow and ice (up to French grade AD ) in

140-574: The 15th century who, according to legend, was buried on the summit of the mountain. It is still known in present-day Arabic as Jabal Mawla el-Hassan (Mountain of Mawla el-Hassan). Mulhacén is the highest peak in Southern Europe outside of the Alps . It is also the third-most prominent peak in Western Europe, after Mont Blanc and Mount Etna , and is ranked 64th in the world by prominence. The peak

160-459: The Alboran Sea. The crustal structure of the Gibraltar Arc is characterized by an arcuate bulge parallel to the arc, with crustal thinning occurring uniformly from the margins of the mountain ranges towards the Alboran Sea. The lithospheric mantle also has an arcuate bulge below the arc with extreme mantle thinning in the Alboran Sea, which is the typical structure of a back-arc basin located on

180-666: The External Rif having undergone medium-pressure, low-temperature metamorphism during the Oligocene. Flysch units from the Cretaceous to Early Miocene are located between the External and Internal Zones. These were folded and thrust during the westward migration of the Internal Zones and can be interpreted as the palaeo- accretionary wedge of the subduction system that was active during

200-692: The Lower and Middle Miocene. Mulhac%C3%A9n Mulhacén ( [mulaˈθen] ), with an elevation of 3,482 metres (11,424 ft), is the highest mountain in peninsular Spain and in all of the Iberian Peninsula . It is part of the Sierra Nevada range in the Penibaetic System . It is named after Abu'l-Hasan Ali , known as Muley Hacén in Spanish, the penultimate Muslim ruler of Granada in

220-558: The Maro-Nerja and Yusuf systems. These trend NW and have transtensional deformation. The present-day stress pattern is probably the consequence of the interference between two stress sources: ongoing continent convergence and secondary stress sources from variations in crustal thickness, sedimentary accumulations causing loading, and the active strike-slip fault. The Arc has two sections: the Internal and External Zones. The Internal Zone, which

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240-526: The altitude. Above 2,500 metres (8,200 ft) the climate is Mediterranean -influenced subarctic (Dsc), due to the location's high elevation and low summer precipitation. With June and September being around the threshold of 10 °C (50 °F) in mean temperature to avoid the subarctic classification, the climate at a slightly lower elevation is continental highland climate. At an elevation slightly lower than that classification area; where February means average above −3 °C (27 °F); it falls into

260-661: The concave side of an arcuate mountain belt. A major left-lateral strike-slip fault zone, the Trans-Alboran Shear Zone , crosscuts the Gibraltar Arc with a NE trend from the eastern Betics to the western Rif. It was active during the Neogene, contributing to the westward advance of the Gibraltar Arc. Some of the previous fault segments are active, with left-lateral transpressional faulting and moderate to significant clockwise stress rotations. Oblique to this shear zone, there are two major right-lateral strike-slip fault systems,

280-488: The late Miocene , followed by northwest–southeast convergence from the late Tortonian to present. The Gibraltar Arc was formed during the Neogene due to a combination of western migration of the orogenic mountain front and late orogenic extension. The present convergence rate of the plates is estimated to be approximately 4.5 to 5.0 mm/year with an azimuth of 135–120°. The eastward Gibraltar Arc oceanic subduction system

300-537: The mountain from suspected hypothermia . Initial reports quoting the Spanish Civil Guard stated that the three were ill-equipped for the extreme conditions. This claim was subsequently disputed both by the family and a colleague of one of the climbers, and by one of the rescuers. A plaque dedicated to them has been placed at the summit. Sierra Nevada (Spain) Sierra Nevada ( Spanish: [ˈsjera neˈβaða] ; meaning "snow-covered mountain range")

320-452: The normal cool-summer mediterranean classification transitioning with the hot-summer variety in surrounding lowland areas. This renders Sierra Nevada's climate a highland cooled-down variety of a typical mediterranean climate. Summer and winter daytime temperatures are some 12 °C lower than found in Granada , differences that are even greater in spring as Sierra Nevada takes longer to approach

340-547: The valleys have less regular orientations. This side is dominated by the Rio Genil which starts near Mulhacén and into which many of the other rivers flow. Geologically, the range is composed chiefly of soft micaceous schists , sloping steeply to the north, but more gradually to the south and south-east. According to the Köppen climate classification , Sierra Nevada has a Mediterranean climate , with different variations depending on

360-399: The winter. Mulhacén can be climbed in a single day from the villages of either Capileira or Trevélez , but it is more common to spend a night at the mountain refuge at Poqueira, or in the bare shelter at Caldera to the west. Those making the ascent from Trevélez can also bivouac at the tarns to the northeast of the peak. On 5 March 2006, three British climbers from Teesside died on

380-607: Was active during the Early and Middle Miocene and has likely been inactive since. At this time, the Alboran Sea acted as a back-arc basin during the deposition of accretionary units. Since the Late Miocene, north–south to northwest–southeast continental convergence forced the subduction system along the arc that is oriented N20°E to N100°E. There is a lithospheric slab dipping east from the Strait of Gibraltar down to 600 km depth beneath

400-744: Was formed during the Alpine Orogeny , a mountain-building event that also formed the European Alps to the east and the Atlas Mountains of northern Africa across the Mediterranean Sea to the south. The Sierra as observed today formed during the Paleogene and Neogene Periods (66 to 1.8 million years ago) from the collision of the African and Eurasian continental plates . Central to the mountain range

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