Page 10 - Pepe_Corradino_alii_2018

200 F. Pepe et al. / Geomorphology 303 (2018) 191–209

Fig. 7. Boulders and sockets characteristics in the Punta Fanfalo coastal area. a) Small imbricated group of boulders close to an area where they formed sockets, b) view of rocky platform
edge characterized by sockets formed in different layers; c) recently formed socket with sharp edges and a recently-detached block; d) wood wedged under a boulder.

occurs because of their detachment from the platform edge. Based on The histogram of boulder thickness (Fig. 5) shows two peaks of the
these considerations, we infer that the most common pre-transport set- frequency classes with width of 25–30 cm and 35–40 cm, and two less
ting is the joint-bounded scenario; although a submerged pre-transport pronounced peaks in the classes wide 45–50 and 65–70 cm. The com-
scenario seems to be more appropriate for some isolated boulders parison between the values of the frequencies peaks class with the
(Fig. 2g). The hypothesis both of free and joint-defined submerged boul- more frequent thickness of bedding planes recognized within the fore-
ders is supported by a) the presence of submerged free boulders and/or shore complex system (Fig. 3)demonstratesthat the thickness ofbed-
b) sockets carved out on the submerged rocky platform, as well as ding planes controls the C-axis dimension of boulders.
c) several blocks showing encrustations of vermetids on their surfaces Fig. 9a also highlights that the fracture spacing of the Far1 and Far 2
(Fig. 2d, g, h). sets corresponds to the B- and A-axes of joint-defined blocks not yet

Fig. 8. Rock samples taken from boulders for lithological analysis and measurements of bulk densities (note, the figure displays only four of the 10 rock samples dataset collected in the
investigated localities). S1, S3 and S8 are rock samples taken from boulders detected in the Punta Faraglione coastal zone. They represent, respectively, rock samples of fossiliferous
polygenic-conglomerate, bioclastic fine-calcarenite and bioclastic coarse-calcarenite. The sample rock S9 was extracted from a boulder located in the Punta Fanfalo coastal area and
corresponds to a bioclastic fine-calcarenite. Inset a) shows a schematic geological profile across the Punta Faraglione coastal zone where the samples S1, S3 and S8 were taken. Legend:
4) fossiliferous conglomerates and bioclastic calcarenites (Early Pleistocene); 6: fossiliferous carbonates (Late Triassic-Early Jurassic). See inset 2 of Fig. 1 for localization.