Petrographic studies on the NASA Lunar Sample thin section set : II. : various counterparts from the terrestrial, chondritic (NIPR) and artificial ceramic samples

NASA Lunar Sample Educational Set is a valuable source for planetary petrology education. Using the breccias of the Apollo expedition lunar samples we made cosmopetrographic comparisons between the lunar, the meteoritic, the terrestrial natural brecciated samples and the terrestrial artificial breccia-like ceramic ones. The meteoritic samples were studied from the NIPR Antarctic Meteorite Thin Section Set. From this comparative study the selected counterparts and their formation processes were also concluded

Descrizione petrografica di ceramiche comuni di età romana da San Potito in base a sezioni sottili

Twenty Roman Age home-made sherds from Central Italian San Potito locality were studied by petrographic microscopic method. The ceramics were divided into five petrographic groups on the basis of their composition and structural-textural features. Two groups of the ceramics were tempered with clasts of alkaline volcanic origin, which seem to originate from Central-Italian volcanic territory components. The ceramics belonging to the other three groups contained large amounts of limestone and carbonatic fossils, the origin of the raw material was a marine clayish sediment, perhaps flysch

ON POSSIBLE ORIGIN OF BACKGROUND CONTENTS OF HEAVY METALS AND METALLOIDS IN THE SUBSURFACE PENNSYLVANIAN TÉSENY METASANDSTONES, SW HUNGARY

Potentially toxic trace elements such as chromium, cobalt, arsenic and antimony exist in many sediments and sedimentary rocks, and therefore require an understanding of their occurrence, distribution and accumulation in the geologic environment. Ten trace elements (Sc, Cr, Co, Rb, Cs, Hf, Th, U, As and Sb) were quantified by neutron activation analysis in drill core samples comprising medium to very coarse-grained sandstones from the Pennsylvanian molasse Téseny Metasandstone Formation (TMF), SW Hungary. The results reveal a large range of the local background levels of these trace elemental concentrations. With regard to the toxic heavy metals and metalloids, the total Cr concentrations in the sandstone samples have a range of 15–150 mg/kg with a median of 47 mg/kg. Cobalt is present in the range of 7–19 mg/kg (median 9 mg/kg). Arsenic and antimony concentrations vary between 2 and 40 mg/kg (median 5 mg/kg) and between 0.4 and 2.5 mg/kg (median 0.8 mg/kg), respectively. Trace elemental geochemistry of the samples reflects the immature petrographic composition of the TMF sandstones, corresponding to a felsic source area, and the presence of abundant illite±muscovite. Additionally, the relatively enhanced As and Sb contents in some samples could be related to hydrothermal activity in the region. Trace elemental concentrations of the TMF samples are comparable to those of world-average siliciclastic sedimentary rocks indicating that the potentially toxic heavy metal contents of the TMF do not significantly affect the groundwater quality in the region. Water-rock interactions at the marginal area of the Drava depression, however, may contribute some metalloids to groundwaters if the hydrogeochemical conditions are favourable for their release into solution

Kerámiák archeometriai vizsgálata : kőzettani és geokémiai módszerek

Ceramics are artificial metamorphic (metasedimentary) rocks. Fundamentally they consist of plastic clay and non-plastic clasts, which had been fired at mediumhigh temperature during production. The samples were subject to scientific research carried out with mineralogical, petrographic and geochemical methods, which provide us information about the raw material and the production technology Petrograhic description with polarization microscope is the basis for the study. It can help us define the non plastic clasts (temper material), characterize the structural features of the ceramics. All these inform us of the site of production, the manufacturing technology and the rim and glaze of ceramics, too. Petrographic analysis offers information about the use of pottery and the secondary phases which form during the use and the time of the burial. The results of X-ray powder diffraction gives us details regarding the fine-grained raw material and the firing temperature. Data from chemical analysis may mainly complement and clarify the result of petrographic research. We may receive information about the origin of the raw material of the ceramics if we know well the geology of the site. We also need to perform a comparative study of the clayey sediment which might be regarded as the raw material found near the site or examine the material of the kiln available. Ceramics can be categorized based on the type of raw material and the production technology. Further categories are the following: ceramics made of local and non-local (imported) raw material. The scanning electronmicroscopic and electron-microprobe analysis (EPMA) may well complete the result of basic studies. Archaemetrical investigation of the ceramics is very successful if an antrophologist or a scientific expert select the samples for the scientific researches and they evaluate the results of them