Geographical Situation and Geology of the Sierra
The Sierra de Atapuerca, located a few kilometers east of Burgos, Spain, is a small range of hills formed around the Cumbre de San Vicente (alt. 1085 meters above sea level) that forms part of the Corredor de la Bureba, the main pass connecting Africa and the western regions of the Iberian Peninsula with the rest of Europe. It has been used by both humans and animals since remote times to migrate between the watersheds of the Duero, flowing into the Atlantic, and the Ebro, flowing into the Mediterranean. This makes it a very good place for hunters to live, because animals moving from one area to the other must concentrate here.
Geologically, the hills are built of limestone and sandstone from marine deposits laid down during the Upper Cretaceous period (80-100 million years ago), overlain by alluvial terraces deposited by the Río Arianzón which now runs to the south of the hills. The limestone is riddled with fissures, caves and underground streams. These caves and fissures have provided shelter and places of magic for man for more than a million years.
The Coming of the Railroad and Exposure of the Caves
About 65 kilometers east of the Atapuerca there is a range of mountains called the Sierra de la Demanda, an extension of the Iberian System running off toward the southeast. In this range of mountains there are deposits of coal and iron. In 1896 permission was granted to The Sierra Company Ltd. to build a narrow gauge railroad from the mines in the Sierra de la Demanda to the main line running from Burgos to the steel mills of Bilbao in the north. The railway was completed in 1901, continued operating for a few years, and went broke.
During construction of this mining railroad a cut was made through the Sierra de Atapuerca of about one kilometer in length, and as much as 20 meters in depth in places. The cut exposed several caves, pits and fissures that had been covered previously. With the railroad long abandoned, in 1950 this same cut began to be exploited as a quarry for a time.
Early Discoveries and Archaeological Excavation
Caves have always attracted man, and in 1972 a group of Swiss spelunkers entered the Galería del Sílex, where they found funerary relics and wall paintings from the Bronze Age. These discoveries brought the archaeologist J.M. Apellániz to begin excavating in the Cueva Mayor in 1973, which he continued for eleven seasons.
Based on finds of human remains by a mining engineer who enjoyed hunting the fossils of prehistoric bears, Emilio Aguirre began systematic archaeological excavations in 1980. He directed this work until his retirement in 1990, when Bermúdez, Arsuaga and Carbonell became co-directors of the continuing project. The discoveries have been astounding, and have pushed back the time of previously known human habitation of Europe from one-half million years ago to at least one million years, with the discovery last month (June 2007) of a fossil tooth from a common ancestor of modern man and Neanderthal man.
In 1992 a skull of Homo heidelbergensis in nearly perfect condition was found; the jaw was located the following season. An intact pelvis has been recovered that shows a male of about 5 feet 9 inches in height, and weighing about 200 pounds with a very heavy bone structure. A new species of human was discovered here, classified as Homo antecessor in 1997. Based on these finds, the area was designated a World Heritage Site by the United Nations in 2000. The future will bring more discoveries, and we can begin to understand our human roots in a way never before possible, thanks to a defunct railroad.
References:
"Atapuerta", article on website Antropos. (In Spanish, author and date unknown)
Arsuaga, JL; Lorenzo, CL; Carretero, JM; Gracia, A; Martínez, I; García, N; Bermúdez de Castro, JM; Carbonell, E (1999). "A complete human pelvis from the Middle Pleistocene of Spain". Nature 399: 255-258.
