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Strontium isotopes and selected trace elements (Rb, Sr, REE, Zr, Hf, Th, and U) were measured on samples of Libyan Desert Glass (LDG) and a series of terrestrial materials (rocks, LDG-bearing soils, eolic sand) collected over a large area of southwestern Egypt to identify the LDG terrestrial parent material and the site where impact melting occurred. Samples include Upper Cretaceous hypersilicic sandstones outcropping at or near the LDG strewn field and Lower Cretaceous to Silurian sandstones from the Gilf Kebir Plateau highlands. Strontium isotopes and partially Zr, Hf, Th, and U, possibly reflecting the composition of detrital zircon grains, are effective indicators of the geochemical affinity between terrestrial materials and LDG, unlike Rb, Sr, and REE abundances. The best geochemical affinity with LDG was found in LDG-bearing soils collected at the base of intradunal corridors in the Great Sand Sea. Remarkably, abundances of the Zr group elements of the LDG Zr-bearing phase are distinct from all terrestrial detrital zircons from the area. We suggest a mixture of weathering products from sandstones of different ages, including Devonian and Silurian rocks from the Gilf Kebir highlands, as the most likely source for LDG. A loose sedimentary formation exposed 29Ma ago at the Earth’s surface, superimposed over hard bedrock, might have been the true terrestrial target of the impact, but because of its incoherent nature, it was rapidly destroyed, explaining the complete absence of any evidence of an impact structure.

International audience; In this work, we explored the isotopic composition of faunal (rodents, rhinoceros and bison) and human skeletal remains from the Middle Pleistocene layers of Isernia la Pineta (Molise, Italy). We particularly focused on high spatial resolution isotope analyses of tooth enamel by laser ablation MC-ICP-MS for strontium isotopes and by micro-drilling sampling for oxygen isotopes. Results from bone specimens were compared with the isotope variability of modern plants collected in the area surrounding the site, in a radius of about 30 km. While the human group seems local, macro-mammals show a higher degree of mobility.

During the last decade, the in situ Lu-Hf isotope methodology has been widely used in Earth sciences and the number of laboratories performing Lu-Hf analysis has increased together with dedicated scientific software. However, free and user-friendly software for the Lu-Hf data reduction is currently missing. We present the 'Hf-INATOR', a new interactive Excel spreadsheet, simple to use and completely free (compatible with Libreoffice and Openoffice) that performs data reduction of the Lu-Hf analytical outputs and calculates the main parameters of the Lu-Hf systematic, such as the 2 sigma errors, the epsilon Hf-(0), the epsilon Hf-(t), the T-DM, the T-DM(C) and the f(Lu/Hf).