Sampling and analytical methods

The Frido Unit metadolerites were collected at San Severino Lucano village, at Timpa Della Guardia, Piani Matteo and Fosso Arcangelo localities, located at the Calabria-Lucania border zone (Figs. 1, 2). These rocks occur mainly as m-sized blocks within strongly deformed serpentinite matrix (Fig. 3).

Petrographic and microstructural observations were carried out in selected samples (Table 1); electron microprobe analyses were performed on amphibole, clinopyroxene, pumpellyite, chlorite, and white mica by using a JEOL JXA-8200 probe, equipped with five WDS spectrometers and an EDS spectrometer, at the Dipartimento di Scienze della Terra “Ardito Desio” of the Università degli Studi di Milano. The analytical conditions were: 15 kV accelerating voltage and 15 nA beam current; count time 30 s at peak and 10 s at background. Natural oxides were used as standards.

Symbols for minerals recommended by Siivola and Schmid (2007) were used in the text, tables, and figures. The exceptions are indicated by the following symbols: brAm (brown amphibole), grAm (green amphiboles), blAm (blue amphibole), bl-grAm (blue-green amphibole), Dbt (diabantite); Pc-Chl (pycnochlorite), and Wm (white mica).