Néolithisation et néolithique : Libye et Sahara

Le terme “Néolithique saharien” comprend en général un complexe de traits culturels qui se sont manifestés entre 10 000 et 5 000 ans dans la partie centrale du Sahara comprise entre 15° et 25° Lat. Nord. Parmi les aspects novateurs qui caractérisent ces cultures – différents éléments technologiques, aspects artistiques et modèles d’établissements – ce sont l’apparition de la céramique et la production de nourriture, avec une économie pastorale qui représentent indubitablement les aspects les ..

SUSTAIN drilling at Surtsey volcano, Iceland, tracks hydrothermal and microbiological interactions in basalt 50 years after eruption

The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes that have occurred in basaltic tephra and minor intrusions since explosive and effusive eruptions produced the oceanic island in 1963–1967. Two vertically cored boreholes, to 152 and 192 m below the surface, were drilled using filtered, UV-sterilized seawater circulating fluid to minimize microbial contamination. These cores parallel a 181 m core drilled in 1979. Introductory investigations indicate changes in material properties and whole-rock compositions over the past 38 years. A Surtsey subsurface observatory installed to 181 m in one vertical borehole holds incubation experiments that monitor in situ mineralogical and microbial alteration processes at 25–124 ∘C. A third cored borehole, inclined 55∘ in a 264∘ azimuthal direction to 354 m measured depth, provides further insights into eruption processes, including the presence of a diatreme that extends at least 100 m into the seafloor beneath the Surtur crater. The SUSTAIN project provides the first time-lapse drilling record into a very young oceanic basaltic volcano over a range of temperatures, 25–141 ∘C from 1979 to 2017, and subaerial and submarine hydrothermal fluid compositions. Rigorous procedures undertaken during the drilling operation protected the sensitive environment of the Surtsey Natural Preserve

“Dynamics of populations, movements and responses to climatic changes in Africa”. II Workshop del Forum for African Archaeology and Cultural Heritage.

II workshop organizzato a Roma del Forum per l'Archeologia african

Missione Archeologica Italiana nell’ Oasi di Farafra

WWW. Archeogate.it/egittologia/NILO/missioni italian