Shoreline evolution and modern beach sand composition along a coastal stretch of the Tyrrhenian Sea, southern Italy

Abstract

This contribution focuses on a multidisciplinary research showing the geomorphological evolution and the beach sand composition of the Tyrrhenian shoreline between Capo Suvero promontory and Gizzeria Lido village (Calabria, southern Italy). The aim of the geomorphological analysis was to reconstruct the evolutionary shoreline stages and the present-day sedimentary dynamics along approximately 6 km of coastline. The results show a general trend of beach nourishment during the period 1870–2019. In this period, the maximum shoreline accretion value was estimated equal to + 900 m with an average rate of + 6.5 m/yr. Moreover, although the general evolutionary trend is characterized by a remarkable accretion, the geomorphological analysis highlighted continuous modifications of the beaches including erosion processes. The continuous beach modifications occurred mainly between 1953 and 1983 and were caused mainly by human activity in the coastal areas and inside the hydrographic basins. The beach sand composition allowed an assessment of the mainland petrological sedimentary province and its dispersal pattern of the present coastal dynamics. Petrographic analysis of beach sands identified a lithic metamorphi-clastic petrofacies, characterized by abundant fine-grained schists and phyllites sourced from the crystalline terrains of the Coastal Range front and carried by the Savuto River. The sand is also composed of a mineral assemblage comparable to that of the Amato River provenance. In terms of framework detrital constituents of QFL (quartz:feldspars:aphanitic lithic fragments) and of essential extraclasts, such as granitoid:sedimentary:metamorphic phaneritic rock fragments (Rg:Rs:Rm), sand maturity changes moderately from backshore to shoreface, suggesting that transport processes had a little effect on sand maturity. Moreover, the modal composition suggests that the Capo Suvero promontory does not obstruct longshore sand transport from the north. Indeed, sands displaced by currents driven by storm-wave activity bypass this rocky headland.

Influencing Factors on Petrography Interpretations in Provenance Research—A Case-Study Review

“…The study illustrates rapid compositional maturity for aeolian sand but insignificant compositional change after >1000 km of aqueous transport. A similar lack of mineralogical maturation during longshore transport has been observed for the light-mineral content of coastal sand [84]. Fluvial quartz-feldspar-rich sand also tends to be more feldspar-rich than littoral sand [25].…”

Silting Process and Loss of Posidonia oceanica Meadows in the Tyrrhenian Waters of Calabria (Southern Italy)

“…A majority abundance was observed in the medium sand fraction (size 0.5 mm-0.25 mm) class, where values between 50% and 60% in weight were achieved (Figure 7). A minor percentage of weight (20-30%) is constituted by a coarse sandy fraction due to the high hydrodynamic energy of the sea waves [78], enabling transport processes of the high fraction at elevated depths. The grain size features are very important to assessing the environmental conditions of Posidonia oceanica species, which are highly vulnerable to sediment-level changes [79,80].…”

Filyos Çayı Deltasında (Karadeniz) kıyı çizgisi değişiklikleri ve yakın geleceğe yönelik göstergeler

“…Bir akarsudan denize deşarj olan sedimentlerin yayılış ve taşınma istikametleri kıyı akıntı sistemleri için güvenilir göstergeler olarak kabul edilmektedir (Ouillon, 2018;Morrone & Ietto, 2021). Genel anlamda Sakarya nehrinden, Bartın nehrine kadar Karadeniz kıyıları boyunca sediment yayılış ve taşınma yönü güneybatıdan, kuzey doğu istikametinde olup, bu sediment yayılış ve taşınma yönü Filyos Çayı sedimentleri için de geçerlidir (Norman, 1977).…”