Geological Position of the Bitumen used in Asphalte Pavements

Abstract

The bitumen which has been so extensively used for pavements, &c. is found in considerable abundance, and of the best description, at Bastenne, a small village in the south of France, about fifteen miles north of Orthez. The geological circumstances connected with its appearance being somewhat interesting, a short account of them may be desirable. The country about Bastenne is formed of numerous small conical hills two or three hundred feet high, separated from each other by deep narrow valleys or ravines; they are chiefly composed of a coarse sandy limestone, which M. de Fresnoy places in the cretaceous system; their upper part consists of variously coloured sands and clays from fifty to sixty feet in thickness, the whole being covered by gravel and sand, which extends for many miles in every direction. The sands and clays are usually horizontal, but are occasionally much disturbed and highly inclined; whenever this occurs it is evidently owing to the protrusion of igneous matter, which is then found in connexion with them. The bitumen is worked in three localities near to each other, and the following section was made at the principal mine:— 5 to 15 feet of bitumen which varies much in character, the upper part consisting of looser and coarser sand, with a less proportion of sand, and being chiefly composed of bitumen. 10 or 15 feet of sand without bitumen occurs in some places, although where the bituminous sand is found of the greatest thichness, it the rests upon the

Ochre-based compound adhesives at the Mousterian type-site document complex cognition and high investment

“…This is so because bitumen, flint, and pure goethite ochre do not occur at the same outcrops but must be gathered and transported to produce the composite tool. The Aquitaine basin, where the site of Le Moustier lies, contains abundant bitumen sources (71) and extensive flint outcrops (72), and goethite ochre is naturally available (73). However, the precise origin of the materials used for the Le Moustier multicomponent tools is not likely within close range of each other.…”