53 research outputs found

    Murge and Pre-murge in southern Italy: the last piece of Adria, the (almost) lost continent, attempting to became an aUGGp candidate (MurGEOpark)

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    In 2019, the executive of the Alta Murgia National Park (southeastern Italy) decided to propose its territory as possible inclusion in the network of the UNESCO Global Geoparks. Since then, in cooperation with the Department of Earth and Environmental Sciences (Aldo Moro University of Bari) and SIGEA, it is working to candidate the area as an aUGGp (called “MurGEOpark”). The MurGEOpark comprises the Alta Murgia area, where a Cretaceous sector of the Apulia Carbonate Platform crops out, and the adjacent Pre-Murge area, where the southwestward lateral continuation of the same platform, being flexed toward the southern Apennines mountain chain, is thinly covered by Plio-Quaternary foredeep deposits. The worldwide geological uniqueness is that the area is the only in situ remnant of the AdriaPlate, the old continent almost entirely squeezed between Africa and Europe. In such a contest, AltaMurgia is a virtually undeformed sector of Adria (the Apulia Foreland), while other territories of theplate are, and/or were, involved in the subduction/collision processes. In the MurGEOpark, the crustof Adria is still rooted to its mantle, and the Cretaceous evolution of the continent is spectacularlyrecorded in Alta Murgia thanks to the limestone succession of one of the largest peri-Tethyancarbonate platform (the Apulia Carbonate Platform). The MurGEOpark comprises also the Pre-Murge area, which represents the outer south-Apennines foredeep, whose Plio-Quaternaryevolution is spectacularly exposed thanks to an “anomalous” regional middle-late Quaternary uplift.The international value of the proposal is enriched by the presence of several geological singularities such as two paleontological jewels of very different age: a Neanderthal skeletonpreserved in speleothems within a karst cave, and one of the largest surfaces in the world withupper Cretaceous dinosaur tracks (about 25.000 footprints). Moreover, the close relationships between man and geology are spectacularly documented in the MurGEOpark: among the others, the use and conservation of water in a karst area, the prehistoric and ancestral choices ofurbanization, karst caves traditionally used as religious sites, etc. All these examples demonstratehow the MurGEOpark could offer a good opportunity to spread the geological culture to a wide and diverse audienc

    Nanoparticle Enhanced Laser Ablation Inductively Coupled Plasma Mass Spectrometry (NELA-ICPMS)

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    A sensitivity enhancement methodology for LA-ICPMS based on the surface plasmon resonance phenomenon as a result of metallic nanoparticles (NPs) deposited on the surface of the sample is proposed. Results show that Nanoparticle Enhanced LA-ICPMS (NELA-ICP-MS) increases the sensitivity up to 1 order of magnitude with respect to the conventional LA-ICPMS without any changes of the experimental set up (i.e. laser parameters or gas carrier composition). Different kind of metallic nanoparticles (AuNPs, AgNPs, PtNPs) and substrates (metallic and dielectric -Cu, Cu-based alloys, Ti, glass, Si-) were tested. The enhancement depends on both dropped nanoparticles (kind, concentration and size) and sample tested (investigated element and matrix). Metallic elements show enhancement in both conductive and dielectric matrices, although the better results are obtained on conductive matrix. Different elements show different enhancement in the same matrix, as well as the same element shows different enhancement in different matrices. Differences in morphology and depth of the craters produced by the laser pulse in the presence and in the absence of NPs, as well as the different size and composition of laser-generated particles allow to attribute to a different laser-substrate interaction the observed enhancement. In particular, NPs induce locally more efficient ablation below the ablation threshold, that leads to the formation of smaller laser-generated particles, consisting of target material aggregated around NPs, that exhibit better transport/vaporization efficiency, thus enhancing signals for metallic samples. NPs do not contaminate the sample irreversibly because, after a very limited number of laser shots, they are completely removed from the sample surface. The method developed allows to obtain the same intensity signal as traditional LA-ICPMS by strongly reducing the number of laser pulses on samples, making the technique more suitable for analyses in which negligible destructivity and/or determination of surface-distribution patterns of very thin layers without underlying contamination are demanded. Moreover, it can be particularly useful to cut down isobaric interference (i.e. Cr and Mn interfered by ArO and ArN) because it allow to increase the analyte signal without increasing the interferences, so increasing signal to noise ratio. The undoubted strength of this approach is represented by its simplicity, affordability and fast performance
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