Le falesie costiere tra Sistiana e il Villaggio del Pescatore: caratteristiche morfostrutturali e idrogeologiche

The NW coast of the Gulf of Trieste (GOT) is cut in carbonate rocks which overthrust the Eocene turbiditic succession. The coastal setting is strongly influenced by the structural setting of the GOT. In this paper, the coastal landscape of the NW sector of the GOT, which represents the northernmost boundary of the dalmatic coasts, is discussed. The study area is dominated by high limestone plunging cliffs, with a depth at the toe ranging from 1 m to 7 m b.s.l. at Duino. The northernwesternmost part is dominated by the Timavo springs. Along the coast, the submarine springs can be easily located during dry periods thanks to the significant in temperature and electrical conductivity between fresh- and salt-water. The occurrence of submerged forms related to the tides, such as marine notches and marine terraces testifies the late Holocene tectonic subsidence of the area

Shore grykes along the western Istrian coast

We provided new data on topography, morphology and physical/chemical parameters (pH, T, NO2-, Ca2+, PO43-, NaCl) collected in several shore grykes along the Northwestern Istrian coast, between Savudrija and Zambratija. Six transects, eachcontaining four to five pools, have been surveyed. Three morphological zones have been identified along the selected profiles. Morphological features of the shore grykes along the western Istrian coast are, in fact, closely related to the local tide. High-level pools are affected by karstic processes, and the surface is usually smooth. At their bottom, terrigenous deposits, mainly terra rossa, occur. Seaward, bioerosion prevails and at the bottom of the grykes, sand and rounded pebbles have been found. Chemical/physical parameters suggest that grykes located at lower altitudes are affected by seawater factors, while pools located at increasing altitudes are affected mainly by rainfall and consequentially freshwater or saltwater remaining from rainfalls or storm events. Shore gryke genesis is strongly controlled by geological weakness, along whichthey develop. Their origin is in fact due to local tectonics, while their development is related to the active vertical tectonic subsidence of the study area. Pools located at higher altitudes are mainly affected by solution karst processes, but due to the tectonic downdrop of the area, when the grykes come in contact withsea, they are gradually shaped by marine processes

Quaternary evolution of the fluviokarst Rosandra Valley (Trieste, NE Italy)

The stratigraphy of terraced sediments as well as morphological features of the middle reach of the Rosandra Valley (Trieste, NE Italy) were studied in order to reconstruct its Quaternary evolution. This sector forms a fluviokarst valley, which is characterized by a deep incised gorge with abrasional features. Downstream, the gradient is reduced, the valley widens and terraced deposits occur. Alluvial/colluvial terraces crop out for about 1 to 1.5 km along the creek. They show the coalescence of the alluvial deposits with debrisfalls from the steep limestone slopes and colluvial fans related to some minor tributaries. The highest terrace is roughly 15 m high. 14C datings on a frustule plant collected in the lower part of the deposit (> 45.000 yrs. BP), together with geological and geomorphological considerations, suggested that the terrace scarp could be Middle Pleistocene in age. The geomorphic regime of the creek changed from aggradation to erosion, as recorded by fanhead trenching and incision of fluvial terrace scarps, and it still persists. The tectonic uplift, which is partly responsible for the downcutting of the terrace and is still active, could be related to the SE-NW tilting of the Karst plateau

Quaternary evolution of the fluviokarst Rosandra Valley (Trieste, NE Italy)

The stratigraphy of terraced sediments as well as morphological features of the middle reach of the Rosandra Valley (Trieste, NE Italy) were studied in order to reconstruct its Quaternary evolution. This sector forms a fluviokarst valley, which is characterized by a deep incised gorge with abrasional features. Downstream, the gradient is reduced, the valley widens and terraced deposits occur. Alluvial/colluvial terraces crop out for about 1 to 1.5 km along the creek. They show the coalescence of the alluvial deposits with debrisfalls from the steep limestone slopes and colluvial fans related to some minor tributaries. The highest terrace is roughly 15 m high. 14C datings on a frustule plant collected in the lower part of the deposit (> 45.000 yrs. BP), together with geological and geomorphological considerations, suggested that the terrace scarp could be Middle Pleistocene in age. The geomorphic regime of the creek changed from aggradation to erosion, as recorded by fanhead trenching and incision of fluvial terrace scarps, and it still persists. The tectonic uplift, which is partly responsible for the downcutting of the terrace and is still active, could be related to the SE-NW tilting of the Karst plateau

Geomorphological map of the NW Coast of the Island of Malta (Mediterranean Sea)

This paper presents the results of geomorphological investigations carried along the north-western coast of the Island of Malta. Field surveys, accompanied by aerial photo-intepretation, have led to the production of a geomorphological map at 1:7500 scale which outlines the main processes and related landforms. The latter are the result of the complex interplay of structural, gravitational, coastal and karst processes. Particular attention was devoted to the recognition, identification and mapping of landslides which affect large coastal sectors of the study area, locally giving rise to hazard conditions

Geology of the Classical Karst Region (SW Slovenia–NE Italy)

ABSTRACTThe paper aims to present the geology of the western part of the Classical Karst (NW Dinarides), located at the border between Slovenia and Italy. The work is based on archive, published and new data collected by Slovenian and Italian researchers within several scientific national and Cross Border Cooperation projects. The map, produced at a scale of 1:50,000, summarizes the lithological and structural setting and is supplemented by three geological cross-sections of the study area

Reply to comment by C. Morhange, C. Flaux, P. A. Pirazzoli, M. B. Carre on Holocene sea level change in Malta

The pits of Birzebbugia are located near the present-day mean sea level, and some are partially submerged. They were dated using pottery discovered in an archaeological site close to the coast, dated to the Bronze Age (Zammit, 1928; Abela, 1999). As they have been interpreted as sites for the retting of flax, during their utilization they should have remained dry and the sea could not submerge them. This is the reason why these structures are not directly related to the sea level, as suggested by Biolchi et al. (2011), so they represent an upper limit.peer-reviewe

Geomorphological identification, classification and spatial distribution of coastal landforms of Malta (Mediterranean Sea)

This paper presents the outcomes of a geomorphological investigation carried out along the coasts of the island of Malta and provides a detailed classification of the Maltese coastline based on the identification and definition of specific coastal geomorphotypes. The results of field surveys, supported by air-photo interpretation, have led to the production of a coastal geomorphological map at 1:30,000 scale which outlines the processes and related deposits and landforms. The latter are the result of the complex interplay of structural, gravitational, coastal and karst processes. Moreover, radiocarbon dates of marine organisms encrusted on boulders mapped along the NE coast are presented.peer-reviewe

Holocene sea level change in Malta

A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman Age, sea level was at −1.36 ± 0.1 m, while in the Midde Age it was at −0.56 ± 0.2 m, in agreement with previous estimations for the Mediterranean region. Data indicate that Malta was tectonically stable during the studied period. The occurrence of the present-day notch along the coasts of the island indicates recent vertical stability of the area. The lack of MIS 5.5 deposits all over the island could simply be due to high rates of erosion, as its coasts are highly exposed to storm waves, rather than tectonic movements. However, even very slight vertical movements could completely remove field evidence. The relative stability of the Maltese Islands allowed a first attempt to provide a palaeoenvironmental reconstruction of its coasts at different time windows since the Last Glacial Maximum. The results have been used to infer time and mode of mammal dispersal to the island during the Pleistocene.peer-reviewe