Tommaso Piacentini

Morphostructural elements of central–eastern Abruzzi: contributions to the study of the role of tectonics on the morphogenesis of the Apennine chain

Abstract The relief features of the Apennine chain have been developed in a complex geomorphological and geological evolution from Neogene to Quaternary. In order to define regional geomorphological characteristics of the central and eastern part of the Abruzzi region (Central Italy), between the Fucino plane and the Adriatic coast, a schematic map of morphostructural elements, structural landforms and erosional landforms was constructed. The results point out the clear coherence of present landforms with the tectonic framework in the Abruzzi area. In the Chain area exhumed thrust ridges and faulted homocline ridges are present (generally NW–SE, NNW–SSE, N–S), separated by tectonic valleys, fault line valleys, tectonic basins and tectonic-karstic basins, partially filled up with continental deposits. In the Piedmont periadriatic area the most important morphological elements are represented by homocline relief (gently NE dipping), mesa relief, dip-stream valleys (SW–NE), and alluvial plains. The latter grade eastwards towards the Coastal Plain.

Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000

This paper describes the Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000. The Tremiti Islands, located north of Gargano promontorys coast, are part of a complex geological area within the Adriatic basin, facing the junction between the central and southern Apennines. This area is well known for Neogenic-Quaternary stratigraphic, tectonic and seismologic aspects and is crucial for the definition of Late Quaternary Adriatic basin evolution. The map is the result of a geomorphological study carried out on the islands and the inner continental shelf around them. This study incorporates: (1) field recognition of Quaternary continental deposits and geomorphological mapping, supported by radiometric dating, focused on the morpho-lithostratigraphic correlation of deposits among the different islands and the recognition of landforms that controlled landscape evolution; (2) bathymetric analysis; (3) geomorphological analysis of data from a side scan sonar survey, focused on the recognition of the main submerged landforms, from the coastline down to about 70 m b.s.l.; and (4) scuba-dive geomorphological survey, for improving analysis of geophysical data with direct observations. The study outlines a complex geological and geomorphologic setting. Despite the small size of the islands, the Quaternary continental succession of the archipelago is characterized by widespread deposits, a result of slope, fluvial and aeolian environments. The landforms of the islands are related to karst, fluvial, marine, and gravitational processes. The inner continental shelf features marine and coastal landforms, but also tectonic, fluvial, karst, and slope landforms. The correlation of the below sea-level geomorphological features with landforms and deposits of above sea-level areas, has provided a contribution to the reconstruction of Late Quaternary landscape and geomorphological evolution, as the result of tectonics, sea-level fluctuations and marine, coastal, and continental geomorphological processes.

The role of drainage systems and intermontane basins in the Quaternary landscape of the Central Apennines chain (Italy)

The Central Apennines chain (Central Italy) is an asymmetric NW–SE thrust belt, NE verging, that has developed since the Neogene. The present landscape is made up of alternating calcareous ridges, valleys on pelitic arenaceous bedrock, as well as wide intermontane basins filled by Quaternary continental deposits. The chain is characterised at high elevation by glacial and isolated patches of dissected karst relict landscapes elevations, and by slope landforms, alluvial fans and fluvial landforms within valleys and intermontane basins; in the latter ancient lacustrine deposits are preserved. Intermontane basins, valley and drainage systems, and relict landscapes are affected by active geodynamic processes resulting in regional uplift, extensional faulting and local subsidence, and by Quaternary climate fluctuations. In this work, the main intermontane basins have been correlated along a SW–NE transect, comparing sedimentary sequences and morphotectonic features, the evidence of local tectonics and uplift pulses, and the main features of the drainage systems, in order to outline the drainage changes occurred during the Quaternary in the Central Apennines chain. Along a SW–NE swath profile, min, mean and max topography elevations, the basins’ min elevation, the elevation of the main karst landforms, and the Pleistocene uplift have been compared. These correlations and comparisons allowed us to provide a further contribution to the understanding of the Quaternary evolution of the drainage systems and the landscape of the Central Apennines chain.

Geomorphological Features of Coastal Dunes along the Central Adriatic Coast (Abruzzo, Italy)

Abstract The main geomorphological features of dunes/beaches were investigated along the central Adriatic coast of Italy (Abruzzo). Nine foredune areas typified by established dunes and incipient dunes were investigated through detailed geomorphological surveying and an analysis of historical maps and photographs (aerial and land). The dunes are located along both low and high coasts. The morphology is typical of foredunes, with elongated fields parallel to the coastline. The total linear extension is ∼15,500 m; established dunes are more extended than incipient ones and occupy the greatest portion of the total surface area (∼1,500,000 m2). Analyses of historical maps and photographs (aerial and land) led to the reconstruction of coastal dune morphology from the beginning of the 1800s to the turn of the 20th century, showing a surface reduction >80%. Accelerator mass spectrometry 14C dating, carried out on samples of Helix sp., outlines the minimum age of Abruzzo dune systems at about 730 ± 40 years before present. The overall study enabled the reconstruction of different geomorphological arrangements of the dune areas, allowing us to define the dunes of the Abruzzo coast as seminatural foredunes, with mainly direct and locally indirect management control. The reconstruction of dune evolution identifies Abruzzos oldest recognizable period of aeolian deposition in the late Middle Ages; aeolian deposition was widely active until the early 1900s and dunes were a significant morphological component of the Italian coastal landscape. The first significant human-induced processes began in the 1900s; over the last 50 years human activity has played an important role in the coastal morphogenesis, with direct and indirect effects on coastal dune reduction and removal heavily affecting the whole coastal system.

Morphotectonic map of the Aventino-Lower Sangro valley (Abruzzo, Italy), scale 1:50,000

This work presents the Morphotectonic map of the Aventino-Lower Sangro valley, located in the southern Abruzzi area, and extending from the Apennines chain to the eastern piedmont, from the Maiella Mountain to the Adriatic coast. It is the result of an extensive drainage basin scale geomorphological analysis carried out in the Abruzzi area and incorporates four main sections: orography and hydrography (upper right on the map); morphotectonic section (centre and left on the map); quaternary fluvial deposits and terraces section (right on the map) and the long morphotectonic profile (lower right on the map). The map presented in this work provides a basis for the recognition of morphotectonic features at basin scale, the detection of tectonic control on landscape, and the reconstruction of paleo-landscapes. It contributes to defining the main phases of the post-orogenic landscape evolution of the transition zone between the Apennines chain and the eastern piedmont area, resulting from the combination of alternating morphotectonics and surface processes, due to rock uplift processes, local tectonics and slope and fluvial processes.

Morphotectonic map of the Osento River basin (Abruzzo, Italy), scale 1:30,000

This work presents a morphotectonic map of the Osento River basin, located in the southern Abruzzi area, Italy, flowing on the eastern Apennines piedmont into the Adriatic coast. The piedmont area developed in a marine environment from the Pliocene to the early Pleistocene resulting in the deposition of a clayey-sandy sequence. Afterwards, regional uplift with NE tilting, led to the deposition of a regressive conglomeratic sequence, as the area evolved into a continental environment. Since the middle Pleistocene the landscape developed by regional uplift, local tectonics and geomorphic processes, mostly through fluvial and slope modification. The morphotectonic map of the Osento River basin is the result of a drainage basin scale geomorphological analysis and incorporates four main sections: orography and hydrography section (upper left on the map); main morphotectonic map section (central and right on the map); Quaternary fluvial deposits and terraces section (central-left on the map); longitudinal morphotectonic profile section (lower part of the map). The map presented in this work provides the basis for recognition of morphotectonic features at basin scale, detection of tectonic control on landscape, and reconstruction of paleo-landscapes. It provides a contribution to define the main phases of post orogenic landscape evolution of the piedmont area of the Apennines chain, resulting from the link of alternating morphotectonics and surface processes, due to uplift processes, local tectonics and alternating slope and fluvial processes.

Geomorphology of the floodplain at the confluence of the Aventino and Sangro rivers (Abruzzo, Central Italy)

This paper presents a geomorphological map of the floodplain at the confluence of the Aventino and Sangro rivers (scale 1:10,000), located across the Adriatic piedmont of the Maiella Massif (Abruzzo Region, Central Italy). This area is in the lower reach of the Sangro–Aventino drainage basin, which in the mid-1900s was affected by the creation of four main artificial water reservoirs by damming of the basins major rivers and the related network of spillway pipes for hydropower purposes. This, combined with climatic factors, induced a strong rearrangement of river channels and floodplains. The fluvial geomorphological features have been analyzed through a detailed-scale multi-temporal analysis based on geomorphological field mapping, topographic analysis, and a remote sensing analysis carried out on aerial photos, orthophotos and Lidar images. The map includes three sections: physiographic and geological setting; main geomorphological map; multi-temporal (1954–2009) and morphometric analysis of the floodplain. The mapping is focused on landforms and continental deposits, mainly linked to fluvial, slope and anthropogenic processes, and to 1954 and 2009 river channels planform analyses and the related morphometric parameters, in order to outline the changes in the river dynamics, strongly influenced by anthropogenic intervention. At a local scale, this type of map can contribute to the understanding of the causes, mechanisms and consequences of the changes in fluvial form and support river management. Finally, it may represent a tool for the assessment of natural hazards in landscapes characterized by intense and rapid geomorphological (fluvial) processes, as well as a tool for correct land management.

Near-surface deposits and hillslope evolution of the Adriatic piedmont of the Central Apennines (Feltrino Stream basin and minor coastal basins, Abruzzo, Italy)

This work presents a geomorphological map of the Feltrino Stream basin and minor surrounding coastal basins (scale 1:20,000), located in the south-eastern Abruzzo area (Central Italy), across the Adriatic piedmont of the Maiella massif (Central Apennines). This geomorphological mapping is focused on near-surface deposits and hillslope evolution analysis and includes three sections: main geomorphological map; orography and hydrography; and geomorphological models of hillslope evolution. In the study area, landforms and continental near-surface deposits are mainly linked to slope and fluvial processes, even though structural, marine, and anthropogenic landforms are also present. The mapping is primarily focused on near-surface deposits and landforms related to the evolution of hillslopes, resulting from the combination of tectonic (regional uplift) and surface processes. At a local scale, it can contribute to an understanding of the causes, mechanisms, and consequences of the changes of landforms and hillslopes and help solve engineering geomorphological problems. Finally, it is also a tool for the assessment of geomorphological hazards in landscapes characterized by widespread near-surface deposits and intense and rapid geomorphological processes, as well as a tool for land management.

Geomorphological features of the Montebello sul Sangro large landslide (Abruzzo, Central Italy)

ABSTRACT This work presents the first results of an integrated geomorphological analysis of a large earthflow in Montebello sul Sangro (Abruzzo, Central Italy). The study is based on a multitemporal geomorphological investigation supported by the morphometric analysis of the drainage network and numerical landslide modelling. The multitemporal geomorphological investigation, based on the interpretation of aerial photos, LiDAR data and field geomorphological mapping, outlined the recent geomorphological history and multiple activation phases of the landslides. A 2D Finite Difference Method (FLAC, Fast Lagrangian Analysis of Continua) analysis of the main landslide scarp, affecting the village of Montebello sul Sangro (Italy), was performed. Finally, in order to outline the morphometric features of the landslide area, local slope autocorrelation was used as a morphometric index. The analysis was aimed at studying the evolution of the active current landslide and specifically the possible retreat of the main scarp.

Long-term geomorphological evolution in the Abruzzo area, Central Italy: twenty years of research

Abstract The most recent research studies into the long-term landscape evolution of the Abruzzo area, carried out over the last twenty years at the “G. d’Annunzio” University of Chieti-Pescara, are based on an integrated approach incorporating structural geology and geomorphology and, in particular, the geomorphometry of topographic and hydrographic aspects, geological and structural-geomorphological surveys and mapping supported by morpho-stratigraphic and chronological constraints. The geomorphological analyses have allowed us to outline the main stages of geomorphological evolution and to identify the factors that have contributed to the landscape shaping of the Apennine Chain, the Adriatic Piedmont and the fluvial plains and coastal sectors, up to the Tremiti islands. In the Apennine Chain, landscape evolution — in a ridge, valley and basin system — is connected to the regional uplift, local tectonic subsidence and local base level variations, which have led to changes in the drainage systems, from exoreic to endorheic (in the intermontane basins) and then to exoreic again. In the Adriatic Piedmont, landscape shaping is connected to uplifting and eustatic sea-level fluctuations, which have induced the formation of a structure-controlled drainage system and the shaping of systems of entrenched alluvial fans and large consequent river valleys, with flights of river terraces. In the coastal Adriatic area — composed of a coastal plain-coastal slope system (northern and southern coast) and of a cliffed rocky coast (central coast, Tremiti) interrupted by river valleys — landscape shaping is the result of selective erosion due to the interaction between marine geomorphic processes and slope processes connected to Late Quaternary eustatic fluctuations.