US researchers participate in a study that shows the application of new wood and stone technologies that allowed the construction of an unprecedented monument.
A study published in the journal Scientific Reports , of the Nature group, reveals the exact origin of the colossal stones used to build the Menga dolmen (c. 3800-3600 BC), one of the great megaliths that make up the UNESCO Site of the Dolmens of Antequera (Malaga). This research, in which the ATLAS group of the University of Seville participates under the leadership of José Antonio Lozano, from the Spanish Institute of Oceanography - CSIC, is based on a detailed high-resolution geological mapping, as well as petrographic and stratigraphic analysis of all the stones that make up the great dolmen of Menga. The results show that the gigantic stones, weighing tens of tons (the largest, Cobija 5, weighs approximately 150 tons) were transported from quarries located in the Cerro de La Cruz, located one kilometer in a straight line to the west of Menga.
Soft stones’ for one of the greatest engineering feats of the Neolithic era
The stones used for the construction of the dolmen are mostly calcarenites, a poorly cemented detrital sedimentary rock comparable to those known as ’soft stones’ in modern civil engineering. From this study it can be inferred that the use of soft stone at Menga reveals the human application of new wood and stone technologies that allowed the construction of a monument of unprecedented magnitude and complexity. The Menga stones were transported from the quarry always in a downhill direction, along an average slope of 22°, to the site of the dolmen, approximately 1 km away. The nearby location and the natural fractures present in the quarries would have facilitated the extraction and transport of the huge stones.
Communities with knowledge of rock properties
The location of the quarries and the geological characteristics were an additional critical factor for the Menga site. The use of soft stones allowed Late Neolithic communities to work gigantic stones. This proves that the Neolithic communities had a deep knowledge of the geotechnical and geological properties of the available rocks and the quality of the ground chosen for the foundation. They avoided loams, clays for the location of the Megalith, and the use of unconsolidated rocks for the building. The substrate was therefore carefully selected, pillars were used and water infiltration was avoided, among others, to prevent the deterioration of these soft stones and ensure the stability of the dolmen. For this purpose, an impermeable mound was created. The case of the pillars used in the Menga dolmen is paradigmatic as a device to guarantee the stability and conservation of the great monument.
Intensive planning and logistics for transport
The extraction and transport of the enormous stones from the Cerro de la Cruz to the hill of Menga must have required intensive planning, very precise logistics and enormous investments in manpower. From these results it can be inferred that the carpentry associated with the construction process must have also demanded the use of large quantities of wood. Taking into account the construction of the ramps and paths necessary to move the stones, their size and number (more than 30 large stones) and their fragility, the construction of Menga represents a unique achievement in megalithic engineering in prehistoric Iberia and possibly in Europe. Menga’s Cobija 5, used as a cover slab at the back of the great megalithic temple, emphasizes the magnitude of this achievement, as it is the largest stone used in a composite megalithic monument.
UNESCO World Heritage Site
The Menga dolmen (Antequera, Malaga, Spain), declared a UNESCO World Heritage Site since July 2016, was once the most colossal stone monument built in Europe (3800 -3600 BC), a thousand years older than the first of Egypt’s pyramids (the step pyramid of Saqqara was built between 2700 BC and 2600 BC, at the beginning of the IIIrd Dynasty), while the most recent dates place the first construction phase of the great megalithic monument of Stonehenge, in the United Kingdom, in 3100 BC.
Reference
Lozano Rodríguez, J. A.; García Sanjuán, L.; Álvarez-Valero, A. M.; Jiménez-Espejo, F.; Arrieta, J. M.; Fraile-Nuez, E.; Montero Artús, R.; Alonso Muñoz-Carballeda, F. and Martínez-Sevilla, F. (2023): "The provenance of the stones in used in the Menga dolmen reveals one of the largest engineering feats of the Neolithic", Scientific Reports.
