Weathering of a Tassili Silurian Sandstone, Central Sahara. Preliminary report

Abstract

Partial results of the investigations carried out in various regions of Central Sahara (Paleozoic and Precambrian area - Tassili and Hoggar) are presented. Special attention has been given to geological and geomorphological section across the Tassili-N'ajjer Mts. Development of frost-cryogenic segregation polygonal structures must have been associated with the last Pleistocene cold climatic oscillation. It corresponds with nivational stationary moraines of the Upper Pleistocene in the highest parts of the Hoggar Mts. (2200-2500 m above sea level). Especially, patination and coatings on a surface of different micro- and macro forms are very helpful tool in desert geochronology.