| Ojo Guareña | |
|---|---|
 Site of the natural monument of Ojo Guareña | |
  | |
| Location | Province of Burgos, Spain |
| Coordinates | 43°02′00″N3°39′00″W / 43.03333°N 3.65000°W /43.03333; -3.65000 |
| Geology | Coniacian limestone |
| Entrances | 10[1] |
Ojo Guareña is akarst complex located in theCantabrian Mountains ofCastile and Leon,Spain, declared anatural monument by the government of Castile and Leon in 1996.[1][2] It is composed of over 90 kilometres (56 mi) of galleries and passages within an area of some 13,850 hectares (34,200 acres).[2][3] The limestone formation containing the system is approximately 100 metres (330 ft) thick and sits on a massive water-resistant layer ofmarl.[1][3] The caves were formed in thelimestone byerosion sometime within theConiacian Age. Ojo Guareña was considered the greatest karst system of theIberian Peninsula until 2009, when a significant length of new passages was discovered in theMortillano system.[4] It is also the24th longest cave system.
Archaeological findings in the area indicate that various caves in the Ojo Guareña system were used by humans as early as theMiddle Palaeolithic up until theMiddle Ages.[5] Scientific exploration has also discovered the presence of over 180 species of invertebrates in the complex.[6]
Tourist access to the caverns is permitted, and there is a visitor's centre located inQuintanilla del Rebollar [es].[7]
.jpg)
The karst complex of Ojo Guareña consists of a massive network of over galleries and cavities, not all of which are connected, occupying an area of about 13,000 ha.[8] The main network consists of fourteen caves that are connected with each other over six different levels of the system. The most prominent entry point is at Palomera Cave.[1]
Ojo Guareña was formed by the erosive action of theGuareña andTrema rivers, in addition to the Villamartín stream. These bodies of water run through the lower galleries for most of the year, although during flood season it is possible for the water to enter the higher galleries.[7] Eventually, they return to the outside throughkarst springs at Trema, Torquilla, Torcón and Torcona, located on a lower section of Trema River. The groundwater runs through Ojo Guareña at a speed of 1.5–5 km per day, depending on whether the measurement is made during the drier summer or the flood season. The groundwater feeds anaquifer located in the hinge of the area'ssyncline fold.[8]
A number of birds live in the area surrounding the cave complex, including thegolden eagle,short-toed snake eagle,Egyptian vulture,Eurasian sparrowhawk,Eurasian eagle-owl,griffon vulture,tawny owl, and theperegrine falcon.[2] Inside the caves there are several species ofbats, such as thecave bat,greater horseshoe bat,lesser horseshoe bat, andGeoffroy's bat.[2] Other mammal species that live in the region include thePyrenean desman,wildcat,dormouse or theEurasian otter.[2]
In 2012, a paper was released documenting the presence of 187invertebrate species in Ojo Guareña, belonging to a variety ofphyla. 32 of them were entirely new to science.[6] Of the more than 200cave-dwelling aquaticinvertebrates that are known in Spain, more than a quarter of them were discovered in Ojo Guareña.[6]
The vegetation in the Ojo Guareña area is very diverse due to its location in a transition zone between theMediterranean andEuro-siberian climate regions. The surface of the natural monument is occupied bymeadows,grasslands,heathlands andIberian forests. A number of types of trees are found in these forested areas, including multiple varieties ofoak,beech,hazel,poplar,alder,pine, andaspen.[2]
.jpg)
Evidence has been found to indicate the presence of human beings in and around the caves of Ojo Guareña from at least as early as theMiddle Palaeolithic up until theMiddle Ages.[5]
The oldest signs of human presence, including cave paintings and tools, in the complex of Ojo Guareña are in the cave of Prado Vargas.[9] Excavations in 1973 located prehistoricpottery fragments. In 1986, more pottery fragments andstone tools were located, indicating a possibleNeanderthal presence.[10] In 2006, some 400Mousterian pieces were located and the site was classified as anarchaeological industry.[10] Impressions of footprints making a round trip, accompanied by torch fragments that have beenradiocarbon dated to as old as 15,600 years, indicate that the cave has been in use for millennia.[11]
In the Cave of Kaite, paintings have been found that appear to representdeer.[12] On the walls and the vault of theSala de la Fuente, or Fountain Room, are paintings that depict people, animal forms, and geometric drawings. These images span a period of time between the lateNeolithic and the beginning of theBronze Age.[12]
On March 14, 1996, Decrees 60/1996 and 61/1996 were issued, approving the Natural Resource Management Plan for Ojo Guareña (Burgos) and declaring the official status of Ojo Guareña as Natural Monument of Ojo Guareña (Burgos). Decree 174/1998, of September 3, 1998, regulates the composition of the Governing Board of the Ojo Guareña Natural Monument.[13]
{{cite journal}}:Cite journal requires|journal= (help)CS1 maint: multiple names: authors list (link)| International | |
|---|---|
| National | |
