PRIMI DATI SULLE RICERCHE MINERALOGICHE DELLA FRAZIONE PELITICA DELLA SUCCESSIONE LAGONEGRESE DELLA RUPE DEL CORVO (VAL D' AGRI, BASILICATA)

Abstract

A mineralogica! study on the clay-rich sediments of a suc­cession containing "Argille varicolori" and overlying the Mesozoic Lagonegro Unit has been performed. The sampled area is located in the Lucanian sector of the Southem Apennines in the Alli R. valley (Agri R. valley). The mineralogy of the <2µm, 2-16µm grain-size fraction and whole-rock samples has been obtained by XRD. Data show similar mineralogica! associations of the Mesozoic Lagonegro Unit and the overlying deposits of "Argille varicolori" and "Arenarie di Corleto" units and point out a gradual increase of the content of il­litic layers in the 1/S mixed layers moving from the youngest unit to the oldest one of the analyzed succession. The most important varia­tion, visible only inside the "sicilide" Unit, consist of a decrease in caolinite amounts and a subsequent increase of mica amounts. This variation suggests that the "Argille varicolori" and "Arenarie di Cor­leto" are the result of changes occurred in the same depositional ba­sin of the Mesozoic Lagonegro succession.