Pietra Leccese Research Articles

Just a different place to graze? An unusual occurrence of the echinoid feeding trace Gnathichnus pentax on a marine vertebrate coprolite (Miocene, Italy) and its palaeoethological implications

Faeces produced by marine vertebrates and macro-invertebrates contain sufficient organic matter to represent a usable food source for a wide array of macroscopic animals. In some extant marine environments, coprophagy even represents a crucial trophic interaction in food webs. In ancient ecosystems, coprophagy by macroscopic animals is occasionally exemplified by coprolites that exhibit biting traces or burrows. Here, we report Gnathichnus pentax on an exquisitely preserved vertebrate-bitten vertebrate coprolite from the marine calcareous deposits of the Pietra leccese (Miocene, southern Italy). This unusual occurrence is interpreted as evidence of the feeding activity of a regular echinoid; in particular, it may represent either exploratory coprophagy or the browsing of an algal (microbial) film that locally developed on the exterior of the faeces. Strengthening the former interpretation, the development of microbial communities on submerged faeces often leads to their destruction; furthermore, some extant Antarctic echinoderms are well known to ordinarily feed on vertebrate faeces, and coprophagy is believed to be fairly widespread among sea urchins. Supporting the algal browsing hypothesis, in turn, only a limited area of the external surface of the faeces was subject to grazing, and the resulting trace is neatly defined, which suggest that the feeding sea urchin targeted a precise location on the dung's exterior when the latter was already rather firm. To our knowledge, the G. pentax specimen studied here represents the first published record of this ichnotaxon on a coprolite.

Biting in the Miocene seas: estimation of the bite force of the macroraptorial sperm whale Zygophyseter varolai using finite element analysis

ABSTRACT Differing from the extant physeteroids, macroraptorial sperm whales are currently regarded as apex predators of the Miocene seas based on several morphofunctional observations. Here, we estimate the bite force of Zygophyseter varolai, a macroraptorial physeteroid from lower upper Miocene strata of the Pietra leccese formation (Apulia, Italy) using the finite element analysis (FEA). To explore multiple bite scenarios, we set four different load cases on a 3D model of the cranium obtained via digital photogrammetry, considering the temporalis and masseter muscles as jaw adductors. Our FEA simulations indicate that Z. varolai exerted an anterior bite force of more than 4000 N and a posterior bite force of more than 10000 N. These values are similar to those estimated for other marine predators known for their powerful bite. This suggests that Z. varolai might have fed upon medium-sized marine vertebrates like other odontocetes. Considering the significant difference observed between the anterior and posterior bite forces, Z. varolai likely fed via ‘grip-and-shear’ feeding, snapping the food items with an anterior bite and then cutting them with a powerful posterior bite. Other macroraptorial sperm whales such as the roughly coeval Acrophyseter from Peru likely employed the same feeding technique.

Pietra Leccese and Other Natural Stones in Puglia Region: A New Category of Building Materials for Radiation Protection?

In this paper, an in-depth and systematic study of the radiological characterization of three types of Puglia region natural limestones (Pietra Leccese, Pietra Mazzara and Carparo) was carried out. The investigation was performed by XRF spectroscopy for a chemical analysis, and gamma spectroscopy of the specific activity concentration of natural radionuclides 226Ra, 232Th, and 40K. Although the limestone does not fall within the category included by Italian Legislative Decree 101/2020, the gamma index was calculated using the results of the gamma spectroscopy measurements. For Pietra Mazzara and Carparo stones, the gamma index was found to be less than the reference value; conversely Pietra Leccese was found to be higher. To obtain a more complete evaluation of the external exposure, radium equivalent activity and external radiation hazard were calculated for all analyzed stones. The results suggest the need to broadly consider the radiological risk for these stones, and for limestone more generally, when used as a building material.

On the presence of an ocean sunfish (Tetraodontiformes, Molidae) in the Miocene Pietra Leccese formation of Southern Italy

On the presence of an ocean sunfish (Tetraodontiformes, Molidae) in the Miocene Pietra Leccese formation of Southern Italy

Radioactivity content in natural stones used as building materials in Puglia region analysed by high resolution gamma-ray spectroscopy: Preliminary results

In this study, for the first time, was measured the concentration of the natural gamma-ray emitting radionuclides of 238U, 232Th series and 40K in building materials used in Puglia region. The selected samples consist on calcarenitic stones: Pietra Leccese, Pietra Mazzara and Carparo. The results show that the Pietra Leccese specific activity of 226Ra, 238U, 40K are higher than Pietra Mazzara and Carparo ones. 232Th radionuclide activity is in accordance for all samples.Consequently, the gamma index, useful for gamma-ray exposure estimation, was calculated. This value for each analysed sample is below the reference level reported in European Directive 59/2013.

An Inticetus-like (Cetacea: Odontoceti) postcanine tooth from the Pietra leccese (Miocene, southeastern Italy) and its palaeobiogeographical implications

An Inticetus-like (Cetacea: Odontoceti) postcanine tooth from the Pietra leccese (Miocene, southeastern Italy) and its palaeobiogeographical implications

Characterisation of surface finishes on ancient historical buildings in Salento (Southern Italy): An integrated analytical approach to establish the secrets of artisans

Abstract Finishing, i.e. the application of hydrophobic materials is an important treatment for the conservation of stone surfaces and the protection of Cultural Heritage decay. The practice of covering the stone facades of the buildings was also used in the past in Lecce (Puglia, Italy). Historical and oral sources report that natural waterproofing agents were used for aesthetic, protective, hygienic and conservative purposes: walnut oil, caprine, ovine or bovine milk, leaf of the Opuntia ficus-indica, beeswax, and bulb of the Drimia maritima plant. In the present work, it was carried out the first historically accurate reproduction of the ancient finishing techniques used on Lecce historic buildings for scientific research: test specimens of local stones (pietra leccese and carparo), treated according to ancient recipes and subjected to natural and artificial aging, have been studied and the physical and chemical modifications determined. This study permitted to gain knowledge about the ancient finishing techniques and their degradation.

Petrographic features influencing basic geotechnical parameters of carbonate soft rocks from Apulia (southern Italy)

A multidisciplinary petrographic and geotechnical approach, aimed at understanding the conditioning by rock-fabric on the mechanical properties of carbonate soft rocks, is shown in this paper. The analysed rocks extensively crop out in the Apulia region and can be referred to three geological units: Pietra leccese (Late Burdigalian-Early Messinian), Calcarenite di Gravina (Middle Pliocene-Early Pleistocene) and Salentino Supersynthem (Midde-Late Pleistocene). 69 specimens of carbonate soft rocks, belonging to all these units, were selected from different sectors of Apulia region and characterized according to petrographic, physical and mechanical properties. Petrographic data allowed us to group all specimens in the following six classes: i) wackestone; ii) mud-dominated packstone; iii) packstone; iv) grainstone; v) floatstone; vi) rudstone. Differently, uniaxial compression strength (UCS) values classify the most part of specimens in “very low and low strength”, revealing a dominant weak resistance and high deformability. Particular attention has been given to the relationships between petrographic features and physical and mechanical parameters of the Apulian soft rocks by means of statistical tests based on the univariate analysis of variance (one-way Anova) and on the principal component analysis (PCA). At first, statistical analysis revealed that the rock geotechnical values are strictly dependent from the geological units. Particularly, the samples of Pietra leccese show significantly higher means of UCS, Young's modulus (Et), and dry unit weight than samples of the Calcarenite di Gravina Fm. Conversely, samples of this latter unit have significantly higher means of porosity, imbibition coefficient and permeability coefficient than those ones of the Pietra leccese fm. Moreover, statistical analysis was applied to estimate if geotechnical values differ according to the petrographic classes of the Calcarenite di Gravina Fm and to verify the covariance between the geotechnical parameters of this unit. The following results have been remarked: i) floatstone and rudstone have significantly higher means of UCS and dry unit weight, and lower means of porosity than finer-grained classes; ii) mud-dominated packstone has significantly lower means of UCS, dry unit weight, Et and permeability coefficient and higher means of porosity and imbibition coefficient than other petrographic classes; iii) grain-dominated, matrix-free, rudstone and grainstone have significantly higher values of permeability coefficient than mud-dominated classes; iv) the occurrence of carbonate lithoclasts and of different dominant couples of sparry cement in pore spaces, are two of the most important controlling factors of the rock strength, and can also explains much of the intraformational variability observed in geotechnical data.Total porosity has not a clear correlation with permeability. This means that the contribution of isolated pore spaces to the total porosity is relevant in Apulian soft rocks, as also suggested by the relatively low values of permeability compared to the relatively high percentages of total porosity. A multidisciplinary characterization of carbonate soft rocks based on petrographic analysis and geotechnical determination of physical and mechanical properties is here recommended for future studies since this approach can give useful information to understand the peculiar behaviour of carbonate soft rocks and to drive the subsequent geotechnical investigations.

Geomorphological Analysis of Karst Landforms at the Masso della Vecchia geosite (Salento Peninsula, Italy)

The presence of a pedestal rock, locally named Masso della Vecchia, marks a site of relevant geological interest (geosite) in the surrounding of Giuggianello village (Salento Peninsula, Apulia region, Italy). This unusual natural landform and similar others occurring in the same area gave birth to myths and legends. A detailed geomorphological analysis of Masso della Vecchia area has been carried out. The site is placed at about 100 m of altitude on a lower Pleistocene abrasion surface which constitutes the top of the Serra di Poggiardo morphostructural ridge. Locally, the Miocene Pietra Leccese Formation crops out. It is constituted by poorly consolidated, bioturbated, yellowish biomicrites at lower levels rapidly grading upward in massive grainstones rich in glauconite minerals. The entire sequence gently dips northeastward. The geomorphological analysis revealed that the Masso della Vecchia and similar landforms occurring in the area are karstic features produced under a soil cover. Pinnacles, channels, notches, subsoil scallops, half-bells and other typical features have been recognized. The peculiar assemblage of subsoil karst features can be explained taking into account the geological structure, subsoil karst processes and the geomorphological evolution of this area during the Late Pleistocene. Key words: subsoil karren, geoheritage, Salento, Italy.

Colloidal Nanocrystalline Semiconductor Materials as Photocatalysts for Environmental Protection of Architectural Stone

Rod-shaped TiO2 nanocrystals (TiO2 NRs), capped by oleic acid molecules (OLEA), were synthesized with controlled size, shape and surface chemistry by using colloidal routes. They were investigated for application as coating materials for preserving architectural stone of monumental and archaeological interest, in consideration of their self-cleaning and protection properties. For this purpose, two different deposition techniques, namely casting and dipping, were tested for the application of a nanocrystal dispersion on a defined stone type, as a relevant example of porous calcarenites, namely the Pietra Leccese, a building stone widely used in monuments and buildings of cultural and historic interest of the Apulia region (Italy). The physical properties of the stone surface were investigated before and after the treatment with the prepared nanostructured materials. In particular, colour, wettability, water transfer properties and stability of the coating were monitored as a function of time and of the application method. The self-cleaning properties of the TiO2 NRs coated surfaces were tested under simulated and real solar irradiation. The obtained results were discussed in the light of the specific surface chemistry and morphology of TiO2 NRs, demonstrating the effectiveness of TiO2 NRs as an active component in formulations for stone protection.

Coating’s influence on water vapour permeability of porous stones typically used in cultural heritage of Mediterranean area: Experimental tests and model controlling procedure

Abstract Water vapour flux into the porous microstructure represents a crucial factor capable of influencing the degradation of porous materials. This fact is of utmost importance especially considering materials installed in cultural heritage. The necessity to preserve stone artworks pushes to perform surface protective coatings that create an intermediate sacrificial layer between stone and the environment. High hydrophobicity and high permeability of water vapour must be one of the most important requirements of a protective film. These features depend upon the nature of coatings as well as the porous microstructures. In order to control coatings’ effects and their influence on final water vapour permeability ( δ ) properties, a new modelling procedure has been proposed. The study is conducted on a porous limestone, namely Pietra Leccese, which is being largely used for historical constructions in Mediterranean. The average experimental water vapour permeability δ exp is 4.83 × 10 −4 and 3.86 × 10 −4 (g/m d Pa) respectively for untreated and treated PL stone, while the average model prediction δ IFU is 4.87 × 10 −4 and 3.77 × 10 −4 (g/m d Pa) respectively for untreated and treated PL stone. The good agreement between experimental and calculated data shows that the proposed modelling procedure could represent a good tool for designing and controlling protection activity on cultural heritage.

Protective properties and durability characteristics of experimental and commercial organic coatings for the preservation of porous stone

Abstract The application of hydrophobic polymers to stone materials is an effective way to preserve stone artefacts and protect Cultural Heritage from decay. To improve the characteristics and performance of water-repellent treatments, and to avoid the use of harmful solvents, innovative solutions have been widely explored. As recent examples, organic nano-filled photo-polymerizable systems were proposed as free-solvent efficient protective coatings for porous stones. In this paper, the nano-filled coating, based on a methacrylate mixture matrix optimized in previous studies, was applied on two calcareous stone substrates, typical of Apulia Region ( Pietra Leccese , PL, and Pietra Gentile , PG). Its characteristic protective properties (in terms of water-repellency, chromatic modification, capillary water absorption, transmission of vapor water, penetration into the stone) were assessed and compared to the same characteristics displayed by two commercial organic water-borne hydrophobic coatings. Natural exposure and accelerated weathering tests were performed to estimate the long-term behavior of the coatings. The characteristic protective performance displayed by the experimental free-solvent photo-polymerizable coating was found greater than those recorded for the commercial organic products.

A comparative assessment of microwave-based methods for moisture content characterization in stone materials

In this work, the dielectric permittivity of pietra gentile and pietra leccese (two kinds of stone typically found in Cultural Heritage structures of Southern Italy), for different levels of moisture content, was characterized. Measurements were carried out by comparatively using three different probes as sensor (i.e., a patch resonator; an open-ended coaxial probe; and a standard WR90 waveguide) for increasing values of water content. Measurements were performed using a vector network analyzer and a time-domain reflectometer. The obtained laboratory results can be used to derive moisture content/relative dielectric permittivity calibration curves that could be employed, in practice, for noninvasive on-the-field moisture monitoring of pietra gentile- and pietra leccese-made Cultural Heritage structures.

Thermal conductivity of porous stones treated with UV light-cured hybrid organic–inorganic methacrylic-based coating. Experimental and fractal modeling procedure

Abstract This study presents an intermingled fractal model (IFU) capable of simulating the porous microstructure of natural calcareous stone substrate, typical of Apulia Region (Pietra Leccese, PL) used in historical buildings. The developed model is aimed at predicting, by an analytical approach, the thermal conductivity of these materials. To verify the actual ability of the proposed method to predict stone thermal conductivity, the intermingled fractal units model was applied to untreated natural stone, and to the same stone, treated with a novel UV-light curable O–I hybrid coating. The application of hydrophobic polymers to stone materials is, in fact, an effective way to preserve stone artifacts and protect cultural heritage from decay. To this aim, a novel experimental photopolymerizable organic–inorganic (O–I) hybrid protective coating, mainly intended for the protection of PL stone, was previously developed by some of the authors. The innovative hybrid product evidenced an extraordinary hydrophobicity, able to guarantee a very high preservation of the stone from water actions, as well as another important property required to a protective, i.e., a high traspirability of the stone substrate. Furthermore, the experimental product proposed was able to equal the performance of commercial available products, with the adjunctive advantage to be free-solvent.

A NEW RECORD OF MESSAPICETUS FROM THE PIETRA LECCESE (LATE MIOCENE, SOUTHERN ITALY): ANTITROPICAL DISTRIBUTION IN A FOSSIL BEAKED WHALE (CETACEA, ZIPHIIDAE)

A new partial fossil skeleton of Messapicetus longirostris (Cetacea: Odontoceti: Ziphiidae) collected in Cisterna quarry (Lecce) from Tortonian (upper Miocene) sediments of the is described. It comprises the fragmentary skull (including most of the rostrum), parts of the mandibles, five teeth, the fragmentary right scapula, and one vertebral centrum. This new record, here referred to a juvenile individual, expands our knowledge about the skeletal anatomy of M. longirostris ; this species was until now only known by the holotype, an almost complete skull from the same Cisterna quarry. Moreover, the new specimen confirms the distinction between M. longirostris and M. gregarius (late Miocene, Pisco Formation, Peru) based on several osteological characters (e.g., the presence of a distinct maxillary tubercle and prominential notch in the latter species). New dating of layers in Cerro Colorado, the type locality of M. gregarius , suggests that M. longirostris and M. gregarius were contemporaneous sister-species with an antitropical distribution (a biogeographical pattern currently shown by two extant ziphiid genera). Unlike extant ziphiids, feeding predominantly on squid and benthopelagic fish in deep waters, the stem ziphiid M. gregarius was recently proposed to have been a raptorial piscivore who may have fed mainly on schools of epipelagic fish. Similarities at the level of the morphology and proportions of the oral apparatus suggest that the two species of Messapicetus may have occupied roughly identical ecological and trophic niches, a hypothesis supported by the characterization of the Pietra leccese environment as neritic.

Miocene phosphate-rich sediments in Salento (southern Italy)

The upper Middle to lower Upper Miocene (Serravallian to Tortonian) sedimentary succession in Salento (southern Italy) includes glauconite- and phosphate-rich deposits, which are associated with pelagic micrite. In Baia del Ciolo and Marittima (southern Salento), the succession is composed of shallow-water platform carbonates of Late Oligocene age (Chattian; Porto Badisco Formation), which are overlain by a 20- to 30-cm-thick level of glauconite-rich micrite with abundant reworked particles and fossils of the underlying Porto Badisco Formation. This interval is in turn covered by an up to 15cm thick phosphatic crust (“Livello ad Aturia”), which itself is overlain either by a hemipelagic chalk-like carbonate of Middle to Late Miocene age (“Pietra Leccese”; Marittima) or directly by a micrite of Late Miocene age (Messinian; Novaglie Formation; Baia del Ciolo), which shallows upwards into a shallow-water platform carbonate. A large hiatus is present in this succession, which likely includes the Lower and lower Middle Miocene. In the region of Lecce, two discrete levels enriched in glauconite and phosphate—each associated with a major discontinuity—occur within the Pietra Leccese. The strontium-isotope ages derived on phosphate nodules and phosphatized and non-phosphatized fossils and calcareous nannofossil ages indicate a time interval of phosphogenesis between 13.5 and 7.5Ma, with two clusters at 12 and 10.5Ma. The glauconite and phosphate-rich sediments resulted from a current-dominated regime, which was characterized by low overall sedimentation rates, erosion and sediment reworking, and authigenesis. This regime was likely related to a generally westward-directed bottom current, which was forced to upwell once it arrived at the western border of the eastern Mediterranean basin. The timing of the principal phosphogenic phases can only partly be correlated to those of other occurrences in this part of the Mediterranean (Malta, Gozo, southern Sicily, Matese, Latium-Abruzzi platform). The partial diachrony in phosphogenesis may express the effect of lateral switching in and/or focusing of upwelling zones.

Characterization and Provenance of Building Materials from the Roman Pier at San Cataldo (Lecce, Southern Apulia, Italy): a Lithostratigraphical and Micropaleonthological Approach

This study deals with the characterization of building materials used in a monumental pier of Roman age, located at San Cataldo, the main coastal harbour of the Roman town of Lupiae, modern Lecce (Southern Italy). In the manufacture of the outer curtains three different lithologies have been recognized, all comprised in Pietra Leccese Formation, which crops out in a broad geographical area of Salento Peninsula. Microfossils recovered from limestone blocks are used to suggest a provenance for the source-rock. Microfossils include planktonic foraminifera characteristic of the upper Miocene (Tortonian-Messinian) foraminiferal MMi11 (Neogloboquadrina acostaensis Biozone) and MMi13 (Globorotalia miotumida Biozone) biozones. The analysed lithic materials show biostratigraphical characteristics very similar to some samples from Acaya-Struda zone (some 10 km South-West from the ancient harbour): comparative analysis has been performed, supporting a clear identification of the geological origin of limestone blocks. In hydraulic concrete different lithic materials have been used and mixed with a strong mortar. Macroscopic field observation clearly define that limestone clasts, variable in size, derive from the Pliocene Uggiano la Chiesa Formation, that widely crops out locally at San Cataldo; granular fractions of mortar probably derive from beaches and/or sandy dunes, available in the surrounding area, as well.

Hydrophobic photopolymerizable nanostructured hybrid materials: An effective solution for the protection of porous stones

In order to guarantee a very high preservation of stone artworks from water actions, an experimental superhydrophobic photopolymerizable organic–inorganic (O‐I) nanostructured hybrid product, namely HEP, has been developed and tested on a calcarenitic stone characteristic of Apulia Region (Italy), i.e., Pietra Leccese (PL). HEP is a “green” product, not containing harmful solvents, and is able to quickly set and harden at room temperature. The first part of the work was devoted to the analysis of the dimension of the silica nanodomains and the suitability of the liquid system produced to be applied on stone surfaces. To this aim, dynamic light scattering and rheological analyses were performed after different times from the preparation of the O‐I system. The hybrid mixture was subsequently applied on a glass substrate and photopolymerized by UV lamp. Several physical properties (glass transition temperature, transparency, scratch, and surface hardness) were, then, measured on the hybrid coating: a substantial improvement of all the surface properties measured was observed. HEP was, finally, applied on PL elements and different analytical techniques (contact angle, colorimetric and water absorption measurements, liquid water, and vapor water transmission) were used to fully characterize the product in terms of hydrophobicity, protective efficacy, water penetration resistance, and transpiring capability. The protective properties of the novel hybrid coating were also compared with those of two commercial water‐repellent products, applied on the same stone substrate, evidencing that the experimental coating is able to equal the performance of high‐quality commercial products. POLYM. COMPOS., 36:1039–1047, 2015. © 2015 Society of Plastics Engineers

Sunlight curable hybrid organic–inorganic methacrylic‐based coatings: analysis of the cure mechanism and functional properties

An experimental ultraviolet (UV) polymerizable hybrid organic–inorganic protective coating, mainly intended for the surface protection of porous calcareous stone substrates, has been recently proposed and patented. The hybrid product evidenced an extraordinary hydrophobicity character, able to guarantee a high protection of the stone against water actions, as well as a high traspirability. Furthermore, it is able to equal the performance of commercial available coatings, with the important adjunctive advantage to be free solvent. The application of this product involves the use of a “dual curing” treatment, necessary to harden the coating applied on the substrate, representing this latter a technological limit. The dual curing treatment consists of 6 hr of exposure to a UV‐lamp plus 1 hr at 140°C in oven. In order to avoid this procedure, not easy to realize in situ, two different modifications of the composition of the hybrid product are proposed in this paper. The first one allows the photopolymerization of the hybrid coating only by sunlight exposure. The second one, even though requiring a UV exposure to photo‐polymerize the coating, does not need the subsequent thermal treatment at 140°C. Several experimental characterizations were performed on the newly developed hybrid products, in order to select an optimal composition for the formulations. The selected innovative products were, finally, applied on a calcareous stone substrate, typical of Apulia Region (Pietra Leccese, PL). Both coatings exhibit excellent water‐repellent action and a slight variation of the natural stone color. Copyright © 2014 John Wiley & Sons, Ltd.

Experimental Study of the Bond of FRP Applied to Natural Stones and Masonry Prisms

Compared to more traditional techniques, the application of Externally Bonded-Fibre Reinforced Polymers (EB-FRP) represents a viable alternative for the strengthening of masonry structures, also in case of Cultural Heritage buildings where strict requirements need to be met, aimed at minimizing the impact of the intervention. Since the FRP-to-masonry bond behaviour strongly affects design and effectiveness of such interventions, several investigations have been carried out in recent years to study this phenomenon, generally based on the longer experience developed for concrete substrates. Mortar joints, which are geometrical and mechanical discontinuities, distinguish and characterize masonry substrates from concrete ones, and therefore deserve a special attention as far as their role in the bond behaviour is not clarified yet. This paper, aimed at giving a contribution also from a methodological point of view, presents the main experimental results of shear tests carried out on glass composites (GFRP) applied to natural calcareous stones (pietra leccese), to lime mortar blocks and to masonry prisms made by coupling stones and lime mortar. Overall 22 shear tests were performed, keeping a bonded length of 200 mm for stones and mortar specimens while it was changed from 65 mm (corresponding to one stone and one mortar joint) to 195 mm (three stones and three mortar joints) in the case of masonry prisms. The effect of the FRP end anchorage on the test development was investigated as well, and results of the experimental tests are herein discussed in detail.