Pozzetti carsici e processi geomorfologici a Rocavecchia (prov. di Lecce)

KARST SHAFTS AND GEOMORPHOLOGICAL PROCESSES AT ROCAVECCHIA (LECCE PROVINCE, SOUTHERN ITALY) - This study deals with description and preliminary considerations of peculiar karst features developed in the Pliocene calcarenite along the Adriatic coast line of Apulia, near Rocavecchia, an important archeological site which incorporates remains of late Bronze Age, Messapian, Roman and Medieval age. The features object of this study are vertical shafts with diameter ranging from 15-20 to 155 cm, with generally circular shape. Maximum observed depth is about 4 m; however, all the shafts (with the exception of those located along the coastal cliffs) are filled with soil and detritus, which therefore impede to estimate the real depth. The contact between the shaft and the hosting rocks is marked by the presence of a carbonate crust (calcrete). The calcretes, analyzed at the polarizing microscope, appear to be of the laminar type, with laminae of different colours, thickness and microstructures. The high frequency of these features in the surroundings of Rocavecchia, and in the promontory where the remains dating back to the Bronze Age are situated as well, make their study of particular interest, also in the light of possible implications in terms of the paleoenvironmental and climatic reconstruction of this sector of southern Italy. Eventually, some preliminary hypothesis on the genesis and development of the karst shafts are presented.