The Menga dolmen (Antequera, Malaga, Spain), listed in UNESCO World Heritage since July 2016, was designed and built with stones weighting up to nearly 150 tons, thus becoming the most colossal stone monument built in its time in Europe (c. 3800–3600 BC).
Our study (based on high-resolution geological mapping as well as petrographic and stratigraphic analyses) reveals key geological and archaeological evidence to establish the precise provenance of the massive stones used in the construction of this monument.
These stones are mostly calcarenites, a poorly cemented detrital sedimentary rock comparable to those known as ‘soft stones’ in modern civil engineering. They were quarried from a rocky outcrop located at a distance of approximately 1 km.
In this study, it can be inferred the use of soft stone in Menga reveals the human application of new wood and stone technologies enabling the construction of a monument of unprecedented magnitude and complexity.
We conclude that the location of the quarries and geological features was an additional critical factor for the emplacement of Menga. The use of soft stones such as calcarenites allowed Late Neolithic communities to work gigantic stones.
Neolithic communities display a deep knowledge of the geotechnical and geological properties of the stones used and the quality of the terrain chosen as foundation.
They avoided marls, clays and unconsolidated lithologies for stone movement and monument emplacement.
They carefully selected the substrate, used pillars and avoided water infiltration, among others, in order to prevent deterioration of these soft stones and ensure the stability of the dolmen. For this purpose, a waterproof tumulus was created.
The quarrying and transportation of the massive stones from Cerro de la Cruz to the hill of Menga must have demanded intensive planning, highly accurate logistics and enormous labour investments