Assetto geologico e geomorfologico dei territori di Guardia Sanframondi e San Lorenzello
In: Atlante Tematico di Topografia Antica. Supplementi: 15, 2020
In this work, the main geological and geomorphological features of the Guardia Sanframondi and San Lorenzello territories are outlined. The study was carried out by means of classical techniques of geological and geomorphological survey and analysis. Using GIS, data were stored, processed and graphically represented through thematic maps. The substratum of the study area was mainly made up of tectonically-deformed limestones and dolostones, Jurassic to Cretaceous in age, and of calcareous-marly-arenaceous sedimentary successions, Cretaceous to Pliocene aged. On such pre-Quaternary substratum, alluvial, pyroclastic and slope deposits, Pleistocene to Holocene in age, unconformably rest. From a geomorphological standpoint, the local landscape was fairly complex. Both the morphogenesis and evolution were here conditioned by interactions between climate and tectonics and by the different erodibility of the outcropping lithotypes. According to the main geological and geomorphological features, the local landscape was schematically subdivided into three main sectors, i.e. the mountainous sector, the hilly sector and the valley sector. The first includes the calcareous relieves located at the far northeastern and north-northeastern boundaries of the study area, bordered by steep and straight slopes of tectonic origin. The second sector is gently-rolling, dominated by long and gently-sloping land surfaces, deeply dissected by the tributary streams network and intensely affected by mass and water erosion processes. Finally, the valley sector includes both the fossil and active floodplains of the Calore River and Titerno Torrent and is characterized by several orders of terraces. The spatial distribution of both the main lithological units and landforms in the study area were synthesized and graphically represented by means of object-oriented, full-coverage thematic maps (i.e., a Geolithological Map and a Geomorphological Map). Furthermore, the analysis of the spatial distribution of geomorphological evidence of morphodynamic processes allowed discriminating the most stable land surfaces from those more severely affected by erosive and depositional processes. The results were graphically represented by means of a “Map of relative stability of the land surfaces”.