Low-background gamma spectrometry and neutron diffraction in the study of stony meteorites.

Non-destructive characterisation of meteorites is here performed on a stony meteorite. The identification of the sample is performed by low-background γ-ray spectrometry in order to determine the presence of certain cosmogenic radionuclides, whereas a mineralogical phase quantitative analysis is carried out by Time-of-Flight Neutron Diffraction (ToF-ND) on the sample as-it-is. The protocol is then validated by applying micro-Raman Spectroscopy (µRS) and Energy Dispersive X-ray Spectroscopy (EDS). This paper is focused on γ-ray spectrometry, proving the meteoric origin of the sample, and it also presents some preliminary results of ToF-ND.

First attempt to quantify microplastics in Mediterranean Sabellaria spinulosa (Annelida, Polychaeta) bioconstructions.

This work focuses on the arenaceous reefs by the polychaete Sabellaria spinulosa and addresses microplastics pollution. The main aim is to assess microplastics amount in a bioconstruction located in the Adriatic coast of Italy (Mediterranean Sea) through a comparative approach: sea-floor sediment and bioconstruction samples were analysed to quantify microplastics absolute abundance in both substrates. A total of 431 MPs were found in the investigated substrates: respectively 85 % fibers and 15 % fragments. Multivariate analysis indicates that MPs within bioconstruction occur in higher abundances and with different morphologies than in sediment samples. The analysis of bioconstruction polished sections allowed for observation of MPs agglutinated in their original position: higher concentration is reported in inter-tube areas. Results suggest that physical characteristics of MPs could play a key-role in bioconstruction inclusion processes and raise questions on effective role of sabellariid bioconstructions as a trap for this pollutant in the littoral environment.

Combining Micro-Raman Spectroscopy and Scanning Electron Microscopy Mapping: A Stony Meteorite Study.

Meteorite characterisation represents a privileged and unique opportunity to increase our knowledge about the materials composing the Universe and, particularly, the Proto Solar System. Moreover, meteorites studies evolve contextually with the development of analytical technologies. In the present paper, the results from an unclassified stony meteorite (chondrite) characterisation have been reported on the basis of the innovative analytical protocol presented here. Advanced Mapping by micro-Raman Spectroscopy and Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy have been combined to disclose molecular and elemental features on the same regions sample at a micrometric resolution. Thanks to their non-destructive properties, the mapping tools of both instruments have been applied to single chondrules analysis and the best match between the mineralogical information and the chemical composition has been obtained. This combined approach proved to be highly suitable in disclosing the crystallinity features of the phases, with in-depth spatial and morphological details too.