Geological Features and Physical and Mechanical Properties of the Gorgoglione Building Stone of Basilicata (Southern Italy)

Since prehistoric times stones have been widely employed in the construction of historic buildings, floors, and claddings in rural and urban areas. Among the Italian natural stones, the sandstone belonging to the Gorgoglione Formation, known as the Gorgoglione Stone, quarried and worked near the homonymous village in Basilicata (Southern Italy), is usually used as a building material. The Gorgoglione Stone consists of well-cemented turbidite sandstones deposited in a Middle-Upper Miocene thrust-top basin unconformably resting on the external nappes of the Southern Apennine thrust belt. In the Gorgoglione area, it can be observed in either numerous natural outcrops or quarries. This study aims to highlight the geological peculiarities of the Gorgoglione Stone and, in particular, it is focused on its mechanical characterization for assessing the most effective use when employed in construction, such as public and civil buildings, road construction, paving, and small works of art. Based on the experimental results, obtained by samples collected from different quarries, axial stress-strain curves have been plotted, whose analysis has delivered the deformation behavior and the strength characteristics of the stone. The elastic modulus, uniaxial compressive strength, and axial strain at stress peak have been estimated for several specimens. The measured values are typically of a medium-high-strength sandstone. The tested specimens of sandstone exhibit a typical behavior of an elastic-brittle rock, characterized by a linear path and a failure typically of axial splitting. With regard to the results of the physical tests, they showed that the analyzed sandstone is characterized by quite low density and by medium-high porosity and water absorption.