Nicoletta Santangelo

A potential early middle Pleistocene tephrostratotype for the Mediterranean basin: the Vallo Di Diano, Campania, Italy

Abstract A 207-m-long core was taken from the deposits of a paleolake formed in the Vallo di Diano tectonic basin of the southern Apennines, Italy. Fourteen major tephra beds were identified and distributed into three groups based on stratigraphic position, and chemical and mineralogical compositions. In a pilot dating program, glass ages were determined for three of these layers using the 40Ar/39Ar method; two of those layers produced discordant step-heating spectra and provided anomalously old ages. A third layer produced a well-defined plateau age of 0.596±0.006 Ma (2σ) and from its stratigraphic position, is correlated to oxygen isotope (δ18O) stage 15 of the deep-sea record. The climatic history of the paleolake can be interpreted from down-core pollen and δ18O variations, which show a succession of two glacial–interglacial cycles. Extrapolation of ages from the astronomically tuned deep-sea δ18O record to that of the paleolake indicates that the lake existed for almost 0.2 Ma. Potential eruptive source regions for the tephra layers include the Roman Volcanic Province, Roccamonfina and perhaps Mt. Vulture. While further dating is needed, the Vallo di Diano section provides valuable information on Middle Pleistocene climate history for the central Mediterranean region and offers a comparison of terrestrial environmental history to those preserved in marine records.

Late Quaternary buried lagoons in the northern Campania plain(southern Italy): evolution of a coastal system under the influence of volcano-tectonics and eustatism

The Campania Plain is a wide coastal plain characterized by a huge quaternary sedimentary record more than two thousand meters thick. In order to analyze the most superficial portion of the infilling succession an 80 m-long core was drilled in the northern sector of the plain. The upper part of the core is entirely made up of an ignimbrite formation (Campania Ignimbrite, 39 ka), lying unconformably above marine sediments alternating with volcanic products. Macro- and micro-paleontological analysis together with tephrostratigraphy and 39Ar/40Ar dating allowed the paleoenvironmental evolution of the studied area to be reconstructed. The paleogeography during OIS 7 and 5 was characterized by the presence of lagoon systems. These are now located 28 km inland from the present coastline and buried at –40 and –18 m with respect to the present sea level, as a consequence of tectonic subsidence. Two major periods of volcanic activity were recorded in the core prior to Campania Ignimbrite emplacement, confirming the existence of important phases of volcanic activity in the plain during the end of the Middle Pleistocene. The SME multiproxy record represents the first continuous record of volcanic products emplaced in the last 200 ka north of the Campania volcanic sources

Tectono-sedimentary evolution of the Pliocene to Lower Pleistocene succession of the Apricena-Lesina-Poggio Imperiale quarrying district (western Gargano, southern Italy)

The post-Miocene marine succession of the «Apricena horst» is described with the purpose to verify the chronostratigraphic constraints for the type-locality of the Pirro Nord Faunal Unit. The stratigraphic succession has been subdivided in four units bounded by ubiquitous unconformities with evidence of subaerial exposure. The two basal units (dated late Zanclean to at most early Piacenzian) are formally grouped in the Lago di Varano Fm. that on the whole consists of sediments ranging from lagoonal to circalittoral environments. Within the lowermost unit, a megabreccia is interpreted as the product of a tsunami event. The third unit, Gelasian in age, is informally cited as Calcari a Briozoi Fm. The last unit, the Lower Pleistocene Serracapriola Fm., consists of siliciclastic deltaic sediments and represents the closure of the marine cycle. Conspicuous lateral facies and thickness changes, and the frequency of unconformities are the consequence of an intense synsedimentary tectonic activity developed in the frame of the southern Apulia foredeep closure. In the study area, such activity is documented by two E-W trending normal faults which, during Zanclean and at least the earliest Gelasian, controlled the Pliocene horst-graben system of the Apricena-Poggio Imperiale area.

Flash flood occurrence and magnitude assessment in an alluvial fan context: the October 2011 event in the Southern Apennines

This study presents the analysis of flash floods triggered by an extreme rainfall event that occurred on 7 October, 2011, over the Marzano carbonate massif (Southern Apennines). The rainfall event reactivated alluvial fans built up at the outlet of two mountain basins. Detailed geological surveys carried out immediately after the event allowed the reconstruction of the main erosion and depositional processes that occurred both in the drainage basin and in the fan areas. The volume of materials eroded in the basin and deposited in the fan was evaluated by means of accurate topographic surveying and GPS measurements. Morphological and morphometric properties of the basin/fan system as well as the presence of human interventions and structures along the main channel and in the fan area influenced flow propagation. The transported materials came mainly from debris and gravels previously accumulated along the stream beds and mobilised by the flow during the event. No significant evidence of landslide contribution to transported bed load was detected. Extensive damage was done to buildings, river bank structures and agricultural crops. Despite the existence of hundreds of similar alluvial/fan systems in the Southern Apennines, few studies have been conducted to support adequate risk mitigation action in these areas. Indeed, to our knowledge, this is the first study focusing on assessing the magnitude of alluvial fan flooding in the context of the Southern Apennines. Studies like the present one may help determine the volumes involved during flash floods whilst providing support for detailed flood hazard zoning and for risk mitigation planning.

Quaternary evolution of the Southern Apennines coastal plains: a review

Abstract The Quaternary evolution of the main coastal basins located along the southwestern margin of the Southern Apennines has been reconstructed by integrating the huge amount of existing stratigraphical and geomorphological data. The information produced in the last twenty years has shed new light on the recent (late Middle Pleistocene to Present) history of the Campanian and Sele plains or basins. During the early Quaternary, the analysed coastal basins originated as half-grabens in response to opening processes active since the late Tortonian in the southern Tyrrhenian back-arc basin. In some of these basins (e.g. the Campanian Plain), volcanism has also played an important role. In the inner sectors of the coastal basins, the complex interplay between block faulting, sedimentary inputs and glacioeustatic fluctuations gave rise to relative sea-level change and related coastline migrations, leading to the formation of the present-day coastal plains. In the Sele Plain basin, the construction of the present-day landscape mainly resulted from the substantial ceasing of subsidence in the final part of the Middle Pleistocene. Conversely, a strong contribution to the recent evolution of the Campanian Plain has been provided by abundant volcaniclastic aggradation, able to hinder the effect of the vertical motions that occurred in the last 100 ka.

Post flash flood survey: the 14th and 15th October 2015 event in the Paupisi-Solopaca area (Southern Italy)

ABSTRACT In this paper, a 1:5000 map of the geomorphic consequences of the 14th–15th October 2015 flash flood is presented. The most severely affected area (about 13 km2) was located at the footslope of Mt. Camposauro (Southern Italy), between the municipalities of Solopaca and Paupisi. In this area high-intensity and very localized cloudbursts of short duration induced hillslope erosion and sediment delivery from the slopes to the Calore River, activating several alluvial fans. The rainstorm lasted 7 h with a maximum recorded rainfall peak of nearly 140 mm in 2 h. The event map resulting from a geological and geomorphological post-event field survey was supported by satellite images and unmanned aerial vehicle image interpretations, respectively taken one day and one week after the event. The flash flood resulted in no casualties but severely affected the local economy, mainly based on agriculture and wine production.

Multiscale map analysis in alluvial fan flood-prone areas

Several case studies of geomorphological mapping at various scales in order to identify areas prone to alluvial fan flooding are presented in this paper. The selected areas are located in southern Italy and are representative of a geomorphic unit (foothills consisting of coalescent alluvial fans) found throughout the southern Apennines. The medium-scale approach represents the best tool to identify areas susceptible to flooding, using detailed geomorphological mapping of fan systems. It can be considered a preliminary analysis, which provides important information for large areas and identifies zones which need further investigation. Large-scale map analysis may be applied to a single fan and used to distinguish fan portions prone to different degrees of hazard exposure, thus providing accurate information for decision-makers who are called upon to plan hazard management. In both cases, analysis based on detailed geological and geomorphological field surveys is often coupled with remotely sensed data.

Geo-itineraries in the Cilento Vallo di Diano Geopark: A Tool for Tourism Development in Southern Italy

The Cilento Vallo di Diano National Park (Southern Italy) was recently awarded the designation of ‘Geopark’. Situated in the Southern Apennine chain in a typical Mediterranean environment, it is noted for a high degree of geological diversity: Coastal and mountain areas made up both by carbonate and terrigenous successions give rise to a landscape alternating between steep mountainous districts and hilly areas. This territory preserves a large number of geosites, which have been identified and described by previous authors. This paper illustrates two basic geo-itineraries which can help to explain the high potential interest of the area in geotourism terms and which can provide a valid example for further geo-itinerary planning. The itineraries can be used for teaching purposes at different educational levels (students of high school level, schoolteachers, geotourists and geopark guides), as well as for university courses. In addition, non-geologists may follow the itineraries and discover the geological heritage of the park. The first itinerary is located in the inner zone of the geopark. It runs throughout the Alburni massif and explains how karst processes act within a carbonate massif and how they influence underground water storage and circulation. The second is located in the southern coastal sector of the park. It sets out to describe the main Quaternary eustatic sea-level fluctuations and the main coastal morphologies. In both cases, an educational box at the beginning and a reflection box at the end of each itinerary are proposed to facilitate comprehension of the main concepts for visiting non-experts and to convey the main messages of the trip better.

Flash floods in torrential basins: the event of October 14th-15th 2015 in the surroundings of Benevento (Southern Italy)

This paper deals with the description of the flooding event occurred in the surroundings of Benevento (Campania) between 14th and 15th October 2015. Several agricultural and industrial activities were strongly affected by the flooding of the Calore River and by the reactivation of some alluvial fans in the northern piedmont of Mt. Camposauro. The geological and geomorphological survey carried out in the post-event, supported by satellite images allowed for assessing the width, the magnitude and the damages occurred. The analysis of the rain data displayed very high values of maximum sub-hourly intensity, mainly concentrated on some sectors of Taburno-Camposauro Mts. The event resulted in no casualties, but it heavily affected the local economy, mainly based on the agriculture and the wine production.