Archaeometry and Cultural Heritage

Mineralogia Applicata

2) Relative distributions of phillipsite, analcime and tobermorite in the Surtsey drill cores based on A) x-ray diffraction (wt.%) and B) & C) point counts (vol.%). Overall, analcime content has increased at nearly all depths, although it varies from sample to sample. Phillipsite content has noticeably increased only in certain samples above 65.4 m depth. SE-02b contains slightly less phillipsite than SE-01 in the depth interval between 65.4 and 138.4 m. The top and bottom of the poorly altered zones situated between about 138-150 m show phillipsite, but no increase in analcime and tobermorite with depth or time. Tobermorite has mostly increased above water level and towards the bottom of the drill hole, but has decreased overall in the zone of maximum temperature. Due to incomplete core recovery in SE-01 only cutting samples were available at some depth intervals within the poorly consolidated zone and towards the bottom of the drill core. Da Prouse et al., 2020 Alteration progress within the Surtsey hydrothermal system, SW Iceland – A time-lapse petrographic study of cores drilled in 1979 and 2017 Journal of Volcanology and Geothermal Research 392 (2020) 106754

3) Integrated log displaying the relationship between temperature, alteration progress and maturation of palagonitic processes in altered glass determined through petrographic investigations of thin sections in the archived 1979 SE-01drill core and the 2017 SE-02b drill core samples. Da Prouse et al., 2020 Alteration progress within the Surtsey hydrothermal system, SW Iceland – A time-lapse petrographic study of cores drilled in 1979 and 2017 Journal of Volcanology and Geothermal Research 392 (2020) 106754

4) Examples of the behavior of different materials during hot-stage microscope runs at constant thermal rate (A) and in isothermal conditions (B). Lightweight aggregates from waste materials: Reappraisal of expansion behavior and prediction schemes for bloating Construction and Building Materials 127 (2016) 394–409

5) Microstructure and pore distribution of LWA: as cumulative number (A), cumulative volume (B). Lightweight aggregates from waste materials: Reappraisal of expansion behavior and prediction schemes for bloating Construction and Building Materials 127 (2016) 394–409

6) SEM micrographs of lightweight aggregates. Structural Concretes with Waste-Based Lightweight Aggregates: From Landfill to Engineered Materials Environ. Sci. Technol. 2009, 43, 7123–7129

7) Thermal properties of starting materials by TG/DSC coupled with FTIR-EGA. Surface-modi ed phillipsite-rich tuff from the Campania region (southern Italy) as a promising drug carrier: An ibuprofen sodium salt trial American Mineralogist, Volume 103, pages 700–710, 2018

8) Physico-chemical and thermal properties of IBU. Surface-modi ed phillipsite-rich tuff from the Campania region (southern Italy) as a promising drug carrier: An ibuprofen sodium salt trial American Mineralogist, Volume 103, pages 700–710, 2018

Isotope Geochemistry

Chemostratigrafia isotopica di campioni di tefra distali rinvenuti in un carotaggio effettuato nel bacino lacustre di San Gregorio Magno (prov. di Salerno).

La Geochimica Isotopica è il ramo della scienza che utilizza la composizione isotopica degli elementi chimici naturali per eseguire datazioni assolute di campioni di materiali geologici oppure come tracciante di processi geologici.

La Geochimica degli Isotopi Radiogenici utilizza elementi chimici generalmente ad alto numero atomico, quali lo stronzio, il neodimio e il piombo. La composizione isotopica di questi elementi chimici varia in seguito alla loro permanenza più o meno lunga in “serbatoi” della Terra, ossia porzioni diverse di mantello o di crosta. Durante tale permanenza, l’isotopo radiogenico di un elemento chimico aumenta per effetto del decadimento radioattivo di un altro elemento chimico genitore. Per esempio, lo ⁸⁷Sr aumenta nel tempo a causa del decadimento radioattivo del ⁸⁷Rb.

La Geochimica degli Isotopi Stabili utilizza il frazionamento tra gli isotopi di un elemento chimico generalmente a basso numero atomico, quali l’idrogeno, il boro, l’ossigeno, l’azoto e lo zolfo. Il frazionamento isotopico consiste nell’arricchimento di un isotopo più leggero rispetto a uno più pesante, o viceversa, di un dato elemento chimico nel corso di processi naturali, quali: trasformazione di minerali durante un evento metamorfico; precipitazione di minerali di neoformazione nella diagenesi o nella pedogenesi; evaporazione e condensazione di acqua; produzione di materia organica tramite fotosintesi o chemosintesi; evoluzione magmatica a sistema aperto.

Isotopic chemostratigraphy of tephra samples collected from a drill-hole carried out in the San Gregorio Magno lacustrine basin (near Salerno, Southern Italy).

Isotope Geochemistry is the branch of knowledge that uses the isotopic composition of naturally occurring chemical elements to either perform absolute dating of geological material samples or trace geological processes.

The Radiogenic Isotope Geochemistry utilizes chemical elements generally having high atomic number, such as strontium, neodymium and lead. The isotopic composition of such elements varies as a consequence of their longer or shorter persistence in a “reservoir” of the Earth, that can be a portion of the mantle or crust. During such a permanence time, the radiogenic isotope of an element growths because of the radioactive decay of another, parent chemical element. For instance, ⁸⁷Sr increases with time as a consequence of the radioactive decay of ⁸⁷Rb.

The Stable Isotope Geochemistry utilizes the fractionation among the isotopes of a chemical element generally having low atomic number, such as hydrogen, boron, oxygen, nitrogen and sulphur. The isotopic fractionation consists in enrichment of a lighter isotope relative to a heavier isotope, and vice versa, of a chemical element, in the course of natural processes, such as: transformation of minerals during a metamorphic event; precipitation of secondary minerals during diagenesis or pedogenesis; water evaporation or condensation; organic matter generation through photosynthesis of chemosynthesis; open-system magmatic evolution.

Isotope Geochemistry provides efficient tools for investigating several geological processes, such as: assimilation of crustal rocks by a crystallizing magma; mixing among distinct magma batches; mixing among water masses of variable provenance; mixing among clasts of variable composition in a sedimentary basin. In volcanology, ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ²⁰⁶Pb/²⁰⁴Pb and d¹¹B values allow drawing of isotope chemostratigraphies for the reconstruction, in conjunction with the variation of other geochemical parameters, of the evolution through time of the magmatic feeding system of a volcano, even during a single eruption. In petrology, the isotopic tracers, combined with trace element contents and ratios, allow quantitative modelling of magma source regions, as well as genesis and evolution processes of magmas in different geodynamic settings on Earth. Combining radiogenic and stable isotopes (see figure) allows discriminating between mantle source enrichment processes involving sedimentary components, from crustal contamination processes. Moreover, stable isotopes allow estimating the equilibrium temperature of magmatic, metamorphic and metallogenic processes.

Lastly, the isotopes of several metals allow tracing the effects of anthropogenic activities on both environment and man, such as: groundwater and soil pollution by industrial or agriculture wastewaters; soil pollution by aerosols containing tetraethyl lead from gasoline; pollution of human tissues by toxic metals, such as Pb, Cr and Cd. In the agro-food sector, radiogenic isotopes are employed since a few years as tracers for relating several food and beverages (cheeses, vegetables, wine, oil) to the territory where raw materials are produced, in order to shed light on possible food fraud