SANDSTONE PETROGRAPHY: A PROVENANCE INVESTIGATION OF BUILDING STONE FROM MONTE POLIZZO, WESTERN SICILY

Geologic research was initiated to provide building stone provenance data for the Sicilian Scandinavian Archaeological Project. Fifteen samples of building stone (sandstone) were taken from the on-going archaeological excavations (Iron Age) of Stanford and Gothenburg Universities on the top of Monte Polizzo, western Sicily. Geologic maps (1:25,000) were used to locate possible sandstone source areas for the building stone. Fifteen hand samples were recovered from the Terravecchia Formation (11-6 Ma) on Monte Polizzo and from the Marnoso-Arenaccea del Belice (MAB) Formation (4.2 to 2.5 Ma) near the towns of Salemi and San Ciro.

Outcrop and hand sample descriptions were taken from every site location. Average sandstone characteristics included; medium to course-grained, moderate sorting, and moderate to weak induration. Locally some of the sandstone outcrops contained little to no induration making it difficulty to extract intact hand samples.

Preliminary petrographic investigations are taking place to determine the lithic and mineral composition of building stone and hand samples. For the observation of thin section a polar microscope is being used, including a mechanical stage counter. Each thin-section was impregnated with blue epoxy and stained with sodium cobaltinitrite. Five hundred counts per slide are being taken to compile statistical data. Initial results from the Terravecchia Formation samples show a higher abundance of quartz with very few types of feldspar. Calcite cement has overtaken many of the lithic and mineral grains. Sample preparation for heavy mineral analysis, X-ray diffraction, and scanning electron microscopy are underway. These analyses when combined with the on-going petrographic investigation should provide insight into the provenance of the Monte Polizzo building stone.