A STRUCTURAL SEQUENCE IN LOW STRAIN SEDIMENTARY-ROCKS IN THE BEAUFORTGROUP OF THE SOUTH-WESTERN KAROO AND ITS BEARING ON SYNGENETIC AND EPIGENETIC MINERALIZATION

Several sets of planar and linear structures are described from the ve ry gently folded Karoo strata of the northern-most tectonic zone of th e Permo-Triassic Cape Fold Belt. The superposition of these structures reveals a time sequence. Horizontal compression occurred before compa ction was complete. After compaction further horizontal compression de veloped a sequence of structures that are readily interpreted in terms of visco-elastic strain in multilayers. This analysis reveals that a set of mainly antithetic kinks in the form of monoclines developed out of earlier incipient sinusoidal macrofolds during the final stages of horizontal N-S compression. The model is in agreement with evidence f or synsedimentary folding that controlled the sites for erosion channe ls as well as the direction of sedimentary transport. Exploration effo rts for syngenetic and/or fluid controlled epigenetic mineralization i n permeable strata of this fluviatile sedimentary sequence should be d irected along certain structural lines.