Paola Di Leo

Quaternary uplift vs tectonic loading: a case study from the Lucanian Apennine, southern Italy

Abstract Uplift rates have been calculated for a large sector of the Lucanian Apennine (“axial zone” of the southern Apennines, Italy), using both geomorphological observations (elevation values, ages and arrangement of depositional and erosional landsurfaces and other morpho-tectonic indicators) and stratigraphical and structural data (sea-level-related facies, fault kinematics and offset estimations). These data have been compared with those derived from clay mineralogy of Mesozoic pelagic successions (Lagonegro units), outcropping in the same sector of the chain, which gave information on tectonic loading. The values of the Quaternary uplift rates of the southern Apennines axial zone vary from a minimum of 0.2 mm / yr to a maximum of about 1.2 mm / yr . Intermediate values (0.5– 0.7 mm / yr ) have been calculated for the other studied areas. Using geomorphological features and late Pliocene to Pleistocene successions involved in the genesis of erosional and depositional landsurfaces, the same rates ( ∼0.6 mm / yr ) have been obtained for a large time span (about 2 Ma ) in the Melandro basin and adjacent Maddalena Mts. Therefore, during the last 2 Ma , the total uplift amount of the axial zone of the Lucanian Apennine is about 1.2– 1.3 km , with local peaks of 1.5 km . On the other hand, the Mesozoic pelagic units experienced a tectonic loading of 4– 5 km , as estimated by means of illite crystallinity (in the range 0.6– 1.1 Δ°2θ ), percentage of illitic layers in illite/smectite mixed layers (60–90%) and white mica polytypes (in the range of 10–35%). The Quaternary uplift and the related erosion rates of the southern Apennines are unquestionably due to strike-slip faulting and, above all, due to extensional tectonics coupled with thermal/isostatic regional raising. The gap of several kilometres derived from the comparison between uplift rates and tectonic loading values may be explained only by different exhumation modalities starting from late Miocene time.

Geology and geochemistry of Jurassic pelagic sediments, Scisti silicei Formation, southern Apennines, Italy

Abstract A better understanding of genesis and palaeoenvironmental setting of the Scisti silicei Formation (Lagonegro units, southern Italy) was achieved by means of geochemical analysis integrated with new stratigraphic information. Data show that major and trace element geochemistry of ancient clay-rich beds and banded cherts add new insights into the Mesozoic evolution of the Lagonegro basin. Sedimentary contributions to Jurassic shales sampled during this study were mainly derived from two major sources: (i) a dominant terrigenous fine-grained component, having affinity with average upper continental crust that had not undergone intense weathering and (ii) biogenic siliceous material. The latter component occurs in clay-rich layers from the “basal member” of the Scisti silicei Formation. Composition varies up section and accounts for changes in the detrital supply due to bathymetric oscillations. The compositional variations from the basal to the overlying member are consistent with a distal source passing in time to a more “proximal” source, as indicated by sharp changes in the concentrations of detrital elements (Ti, Zr and Nb). It is likely that increased detrital input occurred through turbidity current deposition. Finally, the chemical features of the clay-rich layers from the upper cherty portion of the studied succession imply a progressive deepening of the basin. The lack of any mafic and hydrothermal contributions in the Jurassic shales as well as the continental nature of detrital input suggests that the Lagonegro basin was located between two carbonate platforms, in accordance with the classical restoration of the African–Apulian palaeomargin. Thus, the basin acted as a preferential sink connected to the African cratonic areas through a southern entry point.

Geomorphological, mineralogical, and geochemical evidence of Pleistocene weathering conditions in the southern Italian Apennines

Geomorphological, mineralogical, and geochemical evidence of Pleistocene weathering conditions in the southern Italian Apennines Pleistocene weathering, uplift rates, and mass movements have been studied and correlated in a key-area of the Italian southern Apennines. The study area is the Melandro River valley, developed in a tectonically-controlled Quaternary intermontane basin of the axial zone of the chain. The goal of this paper is to assess ages and geomorphic features of two paleo-landslides and to relate them to values of uplift rates and the climate conditions in the axial zone of the chain during the Pleistocene. Uplift rates have been estimated using elevation and age of flat erosional land surfaces. In the southern area of the basin, the landscape features a wide paleo-landslide which can be ascribed to the upper part of the Lower Pleistocene on the basis of relationships with Quaternary deposits and land surfaces. Another paleo-landslide, in the northern sector of the basin, can be referred to the beginning of the Upper Pleistocene. The correlation between the ages of the two landslides and the temporal trend of the uplift rates allowed us to hypothesize that mass movements occurred in response to uplift peaks that destabilized slopes. Additionally, deciphering weathering conditions by means of the analysis of mineralogical and geochemical signals from landslide deposits and weathered horizons allowed assessment of changes in paleoclimate scenarios during the Pleistocene. The deep weathering was probably caused by the onset of warm-humid climate conditions, which may have acted as a further factor triggering landslide movements in an area already destabilized by the rapid uplift.

Chronological constraints on a Holocene landslide in an intermontane basin of the southern Apennines, Italy: Morphological evolution and palaeoclimate implications

In this work a detailed geomorphological study aimed to reconstruct the Holocene evolution of a slope largely affected by landsliding is presented. The study area is located in the lower valley of the Tanagro River, flowing in the Auletta basin, a Pliocene to Quaternary tectonic depression located along the elongation axis of southern Apennines. In order to investigate the relationships between landscape evolution and triggering factors, and to better constrain the Holocene palaeoclimate scenario in which the mass movements occurred, geomorphological data have been integrated with those deriving by the stratigraphic, chronological, and minero-geochemical analyses of the deposits genetically related to the landslide events. The investigated landslide shows a complex style of activity, with compound rotational and translational slide in the upper part of the slope evolving into flow in the lower part. The chronological evolution of the landslide activity has been constrained through radiocarbon dating of palustrine deposits, genetically related to the landslide, and of interbedded paleosols. On the basis of the presented data, the main landslide event can be placed at the beginning of the Holocene and it is followed by a period of scarse landslide activity, as demonstrated by the sedimentation of palustrine deposits within an endorheic pond. As the small basin was created by a counterslope rotation related to the main landslide phenomenon, its deposits post-date the age of the landslide. The geomorphological features related to the main gravitative event are strongly modified by reactivations occurred at the beginnings of Sub-Boreal period, which represent, in southern Europe, the warmest and wettest stage of the Holocene. As confirmed by mineralogical and geochemical data, intense and/or prolonged precipitation might have played a major role as triggering factor in reactivating the slope movement.

Methods and Technologies for the Cultural Heritages in Basilicata region: a case-study from the coastal belt of Metapontum

The protection and promotion of Cultural Heritage require the application of innovative and non-invasive monitoring techniques for developing complete and detailed projects. The demand of cost-effective and rapid tools promoting long-term strategies for cultural heritage promotion and risk assessment is, therefore, urgent. These issues become indeed of paramount importance in the case of very large areas, such as the coastal ones, where the landscape morphoevolution - driven by climate changes - and the landscape modification - due to agricultural and industrial activities - have dramatically increased the exposure risk of Cultural Heritage. In such a framework, traditional monitoring methodologies appear impracticable. This is the reason why the MeTIBas (Italian acronym for Innovative Methods and Technologies for the Cultural Heritage in the Basilicata region) project has been developed. MeTIBas aims to develop an innovative geoarchaeological investigation approach for large areas (implementation of a Territorial Information System, drawing-up of an experimental digital geoarchaeological map, and creation of an open geoarchaeological database). MeTIBas has been developed in the coastal area of Metaponto, which roughly coincides with the ancient territory of the Greek settlement of Metapontum and its chora and includes a region of about 400 km2 in the Ionian sector of the Basilicata region (southern Italy). The data integration and joint analysis of the huge amount of MeTIBas heterogeneous data have been conveniently carried out in a GIS environment, thus allowing an effective combination of the information from different cognitive levels. Besides, the adoption of a Web GIS environment (a Geoplatform operating in Open Source Framework for Rich Web GIS Applications performed by geoSDI; www.geosdi.org) allows a wide dissemination of the information structured in the MeTIBas project.

Ancient settlement dynamics and predictive archaeological models for the Metapontum coastal area in Basilicata, southern Italy: from geomorphological survey to spatial analysis

In the ancient territory of the Greek settlement of Metaponto and its Chora (Ionian sector of Basilicata, southern Italy) geomorphological mapping, GIS-supported statistics, and landform topographic features were investigated and combined to extract settlement rules and site dynamics. Analyses of environmental dynamics as well as of spatial and temporal settlement evolution were carried through an integrated approach that, starting from a detailed geomorphological analysis, tried to extract the spatial relationships between archaeological site locations and landform/landscape features. Spatial analysis was used to investigate the relationships between environmental parameters and archaeological sites. The advantages to develop a predictive model using Archeological Spatial Evaluation (ASE) analysis lay in the possibility to deeply study the relationships between man and the environment. In the present study, the analysis was carried out in a pioneering way in the ~400 km2 Metaponto territory in order to robustly validate - in the aftermath data - human and territorial dynamics. A model describing interactions between sites and parameters such as elevation, slope, aspect, landforms, land use, and distances from rivers was constructed. Sensibility maps were produced, which will help archaeologists to know how many and which are the parameters increasing the probability to find new archaeological sites as well as how the main geomorphological features of the study area, contextualized within the most likely paleoclimate scenario, affect ancient site arrangement though time. The preferential occupation of mid-altitude marine terraces, and the consequence spreading of agriculture on these territories, is likely due to the existence of well-developed soil profiles on them. Clearly colonists recognized that on these landform units there were the better conditions for the development of massive agricultural practices: since the SP age (4,1 to 2,0 Kyr B.P.) the settlers expands inland looking for most fertile territories as well as for areas sufficiently protected (being far away from the coast). The increase in farmhouses on the top of marine terraces from the FC up to EC-EE periods and the modifications of settlement distribution (gradual abandonment of alluvial) in the Metaponto area is likely related to the acceleration of alluvial processes. The progressive decrease of human occupation during the Hellenistic up to the Roman Age is clearly consequence of the Roman conquest. However, a role played by the increase in flooding occurrence in the coastal plain/floodplains of the main rivers in triggering the abandonment of these territories and marking the beginning of the decadent phases should not be neglected. Productive areas (locally associated to farmhouses) are preferential set along the fluvial incisions (sometime associated to farmhouses), thus implying that productive area setting is strongly linked to the presence of rivers, and of their lower rank tributaries, both as an intrinsic need of manufacturing and to facilitate the spreading of products. From the Classical to the Hellenistic Age until the Roman Age, Necropolis are spread in the entire area, from marine terraces to alluvial plain. On the other hand, Sacred areas - which appearance is recorded starting from the Colony Foundation Age - exhibits a settlement continuity in the study area starting from this time up to the entire Roman period, and the sacred areas setting is strictly associated to the category of Settlement.