## 4 Results and Discussion
### Sedimentological Processes and Facies Recognition
The areal distribution pattern of the BSF2 (Figure 4b) is complementary to that of the BSF1, with values that suddenly increase the near the coast, where they show values close to 1, meaning sediments consisting almost exclusively of carbonate sandy materials and decrease offshore where they reach value lower than 0.1. The origin of the BSF2 sediments is ascribed to the coarse sandy contributions of the local rivers of the Marche Region. They drain the carbonate rocks of the central Apennine and discharge their coarse sediments near the coast, while finer sediments are removed by wave action. The BSF2 facies can be named as _Coastal Facies_ being mainly affected by coastal processes and inputs. The BSF2 presents a smaller extension towards the offshore in front of the Chienti and Tenna rivers and, to a greater extent, in front of the Tronto River where, there is also an area marked by the lowest values. This trend in the areal distribution of BSF2 confirms the greater inputs of fine material from the Chienti, Tenna and, to a greater extent, from the Tronto rivers. Figure 4: Histogram of the factor scores (**a**) and map of the areal distribution of the of the BSF2 (**b**). The third facies (BSF3) explains 1.9% of the total variance and is defined by abundant salts, P, Mn, Ba, Sr, and partially Zr (Figure 5a). The highest values of the BSF3 are mostly found along a belt parallel to the coast in an intermediate position between the BSF1 and BSF2 maxima (Figure 5b) with three maximum areas. By considering the distribution of the BSF3 sediments in relation with the hydrography of the central Adriatic Sea, the silty sediments of the BSF3 are the results of the accumulation at depth where the wave action can remove the finer granulometric fractions, but where the coarse sandy coastal material supplied by the local rivers and reworked by the wave motion, is not deposited. Furthermore, the presence Zr and P also suggest the presence of heavy minerals like zircon and apatite, while the occurrence of Sr and Mn as well as IC suggest the presence of carbonates. These minerals support the residual nature of these sediments in which heavy minerals and carbonate concentrations increase for the removing of lighter minerals and finer grains. The characteristics of the BSF3 are similar to the _Residual Facies_ of [PERSON] et al. (2014) [4] and can then be partially considered as the same _Residual Facies_. The two minima near the coast are in front of the Ete Vivo and Tesino rivers: the two rivers that do not drain the limestone rocks of the Sibillini mountains. This means that the residual sediments are partially associated with the carbonate rocks. By considering single elements, it is worthy to note that the elements that present high affinity with the clay minerals (i.e., Al, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, P, Pb, Sc, Ti, V, Y, Zn, Zr) show a distribution pattern very similar to that of the BSF1  
Figure 5: Histogram of the factor scores (**a**) and map of the areal distribution of the of the BSF3 (**b**). facies_ (_Padanic Facies_) (Figures 6-8) because they naturally tend to accumulate with finer fractions. On the other hand, elements having high affinity with the carbonate minerals (i.e., Ca and Sr) show distribution patterns (Figures 6f and 7e) similar to that of the _Coastal Facies_ BSF2 (Ca) and BSF3 (Sr). This is in full agreement with the findings of the statistical elaboration that connects the same elements with the clay minerals and with the carbonate minerals. For this reason, the anomalies regarding these patterns have been considered to infer anthropic inputs or local natural processes. In this context, an anomaly is recorded in front of the Tronto River where a siliciclastic fine sediment enriched in S is recorded (Figure 6). This is also supported by the sediment description of the box-core upon collection that consisted of compact gray mud with blackish veins and burrows.