Yacimientos mineros del cerro de San Cristóbal

The rañas of Alía, Logrosán, and Cañamero constitute raised areas in the form of a tableland and are an important site at which human presence has been confirmed since the Middle Palaeolithic, between one hundred thousand and forty thousand years ago. One of the most noteworthy details is that there are not only remains of our species but also of Neanderthals. On these rañas we can find several ‘workshops’ for the making of stone tools, which are basically chips which could be used as scrapers for tanning skins or after numerous modifications as spearheads or arrowheads.

The most striking Palaeolithic record of the territory of the Villuerca-Ibores-Jara Global Geopark of the UNESCO is that of the Middle Palaeolithic between one hundred thousand and forty thousand years ago under the predominance of the Mousterian stone-working tradition. Indeed the remains in this area are exclusively of stone and based on numerous findings of carved quartzite pebbles. These tools were made by means of the so-called Levallois technique, which allowed the obtaining of several chips from a quartzite core.

One of the special features of these findings is that they are located on the rañas of Alía, Cañamero, and Logrosán in the open air. This is a very different context to those of the river terraces, caves, or rock shelters on which the studies of this period traditionally concentrated. Another detail which makes the site exceptional is the confirmed occupation of the territory not only by human groups of our own species but also by Neanderthals.

The rañas are major sedimentary formations. They consist of extensive superimposed layers of clayey and sandy materials and quartzite pebbles swept away by the river waters and deposited on these plains or sedimentary basins in which they can now be seen.

The materials originate from the progressive erosion which occurred about two and a half million years ago as a result of tectonic movements during the last stage of Alpine orogeny and of the tropical climate of the late Tertiary and the early Quaternary. Periods with a savannah climate (very dry) alternated with other much more rainy periods in which the heavy precipitation swept away an avalanche of the eroded materials to form the rañas. The rañas of Cañamero, Alía, Logrosán, and Valdecaballeros constitute as a whole an extensive tableland delimited by steep slopes and open to the south and with the upper vertex pointing towards the valley of the River Ruecas. During the Middle Pleistocene this tableland held ecosystems with rich biodiversity in which temperate forests alternated with permanent pools, streams, and meadows in which fish and large herbivores abounded. To this must be added the amount of very hard quartzite which is ideal for the carving processes, the availability of clay to make rudimentary recipients and cabins, a highly accessible topography to facilitate movement, and the visibility of the territory. All these elements provided the perfect habitat for the first communities of hunter-gatherers at this early stage of humanity.

At strategic points such as raised areas on the edge of the tablelands, isolated hills, springs, and pools, sites of occupation or ‘workshops’ for the making of stone tools have been located. The information recently provided by these enclaves clears up some of the major mysteries of this period of our remote past. The remains allow us to assess the various models of occupation of the territory by both our own species and by Neanderthals and the technological evolution of our ancestors from the Palaeolithic.