Giuseppe Sironi

Magnetite Oxidation: A Proposed Mechanism.

All magnetites are oxidized topotactically with formation of solid solution at temperatures below 400�C. The oxidation of hematite-free magnetites proceeds to γFe2O3, whereas in the presence of hematite epitaxial growth of αFe2O3 takes place, with excess iron ions being returned to the solid solution. A method for synthesizing maghemite from natural magnetites is indicated.

Geochemical analysis of Italian oils and asphalts

Abstract Seventy oil and asphalt shows from continental Italy and Sicily were sampled and studied. They were subdivided into five geographical regions, which broadly correspond to geologic provinces. The geochemical method employed involves the fractionation of the oils and asphalts into their different constituents (oily components, resins, asphaltenes and carbenes), as well as the analysis of oily components (elementary analysis, molecular weight and infra-red spectra determination). Spectrographic determination of trace metals was also made in most of the samples. Two methods were employed for the fractionation: solvent extraction and chromatography. A geochemical correlation among the different oils and asphalts within each region was made. The structural differences found among the various oils of each basin were attributed essentially to environmental factors. Remarkable analogies were noticed among the oils from different basins: this is in agreement with the findings on the simple constitution of crude oils and with the ideas on the genesis of petroleum by the selective preservation of naturally occurring hydrocarbons and by minor modifications of organic matter.