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AbstractStudy of profiles, perpendicular to the fold-axes, shows that the folding is disharmonic. Nearly every s?surface is one of d?collement. In some exposures the quartzites are reduplicated by superposed recumbent-folds without infolds of other material. The contacts are tectonic and not stratigraphic. Incipient boudinage is frequent, and nearly all surfaces show well-developed b?lineation.

AbstractPresent knowledge of the tectonics of the Struan area is summarized. Recumbent-folds and incipient boudinage are recorded in the Struan Flags. The different types of lineation present are described; it is pointed out that all types present are mutually parallel. Simple kinematic analysis of an exposure north-west of Dalnacardoch, demonstrates that the lineations coincide more or less closely, with the axis of rolling; they are therefore b-lineations. The need for further field-work is stressed, and the type of data required is indicated.

AbstractThe principal tectonic terms employed are defined. A specimen of sheared quartzite from Corshellach is described. Shear-planes, drag-folds, and lineation are syngenetic. Their geometric relations show that the lineation is in b. Also described is a specimen of folded marble and graphite schist from Urlarmore. Elongated bodies of graphite schist represent tectonic thickening along the antiform hinges. Their maximum dimension, which is much greater than any other, is parallel to the lineation, but they have not suffered extension in this direction. The form of folds and rotated bodies shows that the lineation is again in b. The sense of the movement was towards the south-west. It is believed that throughout mid-Strathspey and Strathavon similar lineations bear the same relations to the kinematic directions.

AbstractOn Ord Ban, quartzite in superposed recumbent folds trending north?south is separated by a slide from mica-schist, granulite, and marble folded in monoclines trending east?west. The reasons for distinguishing between these two styles of folding are given, and the characters of the two styles are contrasted. A fold in quartzite and a fold in marble are described in detail, and kinematic interpretations are attempted. It is concluded that evidence of an early deformation involving mylonitization has been preserved in the quartzite, and that the latest tectonic event distinguishable was the production of the monoclines with attendant twinning of calcite and dolomite.

AbstractIt has been claimed that the hinge of one of the two major recumbent folds of the S.W. Highlands is exposed near Ben Lui. In this paper it is claimed that the form of the outcrops permits the existence of this recumbent fold only if the fold-axis plunges towards the south-west. Evidence is given that the plunge is in fact towards the west, and on this basis a profile has been constructed to illustrate the observed geometrical relationships of the rocks.

AbstractPetrofabric analyses of marble specimens from three widely separated localities in Mid-Strathspey and Strathavon are recorded. Preferred orientation of [0001] in the constituent grains of calcite conforms to a B-tectonite pattern, the symmetry axis (B) of which coincides with the baxis of the megascopic fabric (lineation and fold axis) at each locality. Development of {011?2} lamellae in calcite grains is attributed to late minor compression, the direction of which is more or less horizontal and trends between N.E.?S.W. and E.N.E.?W.S.W.