Lineations in Three Artificial Tectonites

Abstract

Deformation of plastic kaolinite-illite clay caused alignment of authigenic prisms of rutile and tourmaline on surfaces produced by parallelism of the basal pinacoids of the clay-minerals. An a–lineation appeared in the outer layers of an extruded cylinder but a b–lineation in those of a cylinder formed by rolling. A Wineation occurred at the periphery of a circular disc made by spreading. Localized tensional failures, cognate with ac joints, accompanied the b–lineations which were in directions of elongation. The orienting movements were thought to occur in the water-films separating the clay-flakes, but the mechanisms which produce a– and b–lineations are presumably identical. Thus it can be argued that the a–lineation also follows a direction of elongation.