ABSTRACT LXXIV, April 2005 n. 1:

Abstract - During investigation of the diagenetic processes which occurred in the «varicoloured» clay-shale formation along the italian Apennines strip, a lithofacies characterised by the presence of lath-shaped smectite/illite interstratification has been encountered in a zone affected by tectonic stresses; the occurrence area is located along the Sangro river valley, at the border between central and southern Italy.
Detailed SEM observations have evidenced that the clay particles show a morphological transition from flakes to laths. The change occurs via: (i) flattening and thinning of precursor wavy lamellae; (ii) formation of lath aggregates (where the laths are oriented at 60°/120° to each another) that are preserving the original flake contours; (iii) disaggregation of such aggregates into isolated disoriented laths.
Microanalytical EDAX data indicate only slight chemical changes associated with the morphotype transition, mainly concerning Mg and Al contents that are increasing-decreasing, respectively, whereas changes of Si and K amounts were not surely detectable.
Although there are some questions to be clarified (as reaction kinetics, thermal history and role of water content), the observed morphotype transformation is interpreted as a solid-state splitting mechanism, probably influenced by mechanical stresses due to tectonic events and associated chemical changes

GERMANA BARONE*, SALVATORE IOPPOLO, DOMENICO MAJOLINO, CATERINA BRANCA, LIDIA SANNINO, GRAZIA SPAGNOLO and GABRIELLA TIGANO - Archaeometric analyses on pottery from archaeological excavations in Messina (Sicily, Italy) from the Greek archaic to the Medieval age

Abstract - In the present paper we report for the first time all the results obtained through a multidisciplinary investigation on some of the most representative ceramic classes (cooking pottery, tiles, banded, Corinthian B, ionian-massaliote and pseudo-chian amphorae, Zancle type cups, Chalcidian, Attic, banded and a immersione wares, ionian banded B2, black-glazed vessels and a arula sherd) coming from archaeological excavations in Messina, covering a period from Greek archaic to Medieval age. The aim of the present work is to characterize the pottery’s production centers in Messina and to distinguish the local products from the imported ones; this will help us to get further information on the commercial network involving the «Strait Area». The samples were analysed by mineralogical-petrographic and chemical-physical techniques. In particular, X-Ray Diffraction (XRD), thin section analysis by Optical Microscopy (OM), Fourier Transform Infrared Absorption (FTIR), X-Ray Fluorescence (XRF), Inductively Coupled Plasma Mass Spectroscopy (ICP-MS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and Scanning Electron Microscopy coupled with X-ray Energy Dispersion (SEM-EDX) were employed.
The obtained results have evidenced the local production of the coarse potteries (cooking pottery, tiles), contrary to the ionian-massaliote and pseudo-chian transport amphorae that result to be imported products from Locri and, in some cases, from a non located site in Campania; the production of the Corinthian B type amphorae can be attributed both to a Greek (Corfù) and to a colonial magno-Greek (Sibari) imported production center. Finally, for what concerns the fine pottery, the Chalcidian, banded, ionian B2, a immersione and Zancle potteries result produced in the «Strait area», whereas the Attic ceramics are imported from Greek production centers.

Abstract - Foid-bearing syenite cognate xenoliths represent fragments of the upper peripheral parts of the K-phonolitic portions of the 79 AD magma chamber, wrenched during the explosive eruption. Abundant multiphase fluid inclusions are hosted within K-feldspar and coexist with rare silicate melt inclusions. This gives evidence to the exsolution of a magmatic volatile-rich phase from the peripheral parts of the silicate magma chamber. The characterization of daughter mineral assemblage of these fluid inclusions, by SEM-EDS and Raman spectroscopy, indicates two ubiquitous main components: Na-K chlorides (halite + sylvite) and Na-Ca carbonates (calcite ± nahcolite). Microthermometric experiments indicate nearly magmatic trapping temperatures (760°C to 830°C) of the homogeneous chloride-carbonate liquid. Cooling of such liquid produces two immiscible melt phases (chlorides and carbonates) at 455-435°C. This suggests that a hypersaline-carbonate fluid, exsolved from the silicate magma, can further experience another unmixing event that would occur in essentially «post-magmatic» environment.

Abstract - — Twenty-one mortar samples taken from the walls in the southwest side of the Fortezza delle Verrucole (IX-XVIII century) – S. Romano in Garfagnana (Lucca, Italy) – have been analysed to characterise their binder and aggregate fractions. The chemical, mineralogical, petrographic and physical data collected on the bulk mortar samples show that the stone walls were built up using different mortars. The mortars with a hydraulic-binder are prevailing on those with an air-hardening lime binder. The older mortars, coming from the walls built before the XV century, were produced mixing lime putty with locally available sands. They are characterized by a sandy aggregate with grain size from medium to very coarse and by a number of snow-white lumps, due to a not complete mixing between binder and aggregate. This last feature suggests that the mortars were prepared, as it was usual in ancient times, hand-mixing the lime putty added to the sand. Hydraulic and highly hydraulic limes and, perhaps, cement mortars were later employed during operation of renovating and restoring.

Abstract - Samples of cooking ware from the Sacello degli Augustali, a worship place of the ancient Misenum, were investigated from an archaeometric point of view. On typological basis (shape, accurate polished surface, typical volcanic inclusions) some of them were considered as belonging to the so-called «Pantellerian Ware». The petrographical and mineralogical study allowed to identify three groups characterized by different volcanic temper. Six samples instead of four were attributed to Pantellerian Ware due to the occurrence of phases typical of magmatic evolved peralkaline rocks. A second group was identified for the presence of a volcanic temper typical of calcalkaline rocks and tentatively assigned to an Aeolian provenance. The third group shows abundant trachytic and leucititic rock fragments and likely represents a local production.
It is remarked the good technological properties of the cooking ware from Pantelleria due to the use of abundant and well sorted temper, non calcareous clays and low firing temperatures that provide the manufact a low dilation coefficient and good resistance to strong thermal shocks. These features along with a well standardized manufacture that makes these potteries suitable to be transported, allowed to achieve a large diffusion of the «Pantellerian Ware» within the Mediterranean Sea, from the African through the Spanish coasts, and in the Gulf of Naples and Pozzuoli.

Abstract - European non-sulfide Zn deposits, mainly hosted in carbonate rocks and considered so far of supergene origin, represent the historical basis for zinc mining and smelting industry. They were called «Calamine», from the famous Belgian locality where a mixture of Zn-carbonates {smithsonite = ZnCO₃, hydrozincite = Zn₅(CO₃)₂ (OH)₆, Zn-silicates {hemimorphite = Zn₄(Si₂O₇)(OH)₂.H₂O, willemite Zn₂SiO₄} and Zn-clays has been exploited for centuries. A fluid inclusion study has been carried out on Belgian willemite samples, in order to gain information on temperature and salinity of the fluids involved in the formation of the non-sulfide ore deposits. Among all (observed?) inclusions, 80% are monophase (L) and 20% liquid-rich two-phase (L+V). Albeit widespread necking-down and leakage phenomena have affected most of the fluid inclusions trapped, a reliable set of homogenization temperatures, ranging between 80 and 190°C, has been collected from the two-phase inclusions. Tm data suggest salinities between 0 and 5 wt. % NaCl equiv. The detected Th intervals match temperature ranges measured in other willemite ores throughout the world, part of which are considered of hydrothermal origin. These fluid inclusion data pose many questions on the genesis and evolution of Belgium non-sulfide deposits.