A structural sequence in low strain sedimentary rocks in the Beaufort Group of the south-western Karoo and its bearing on syngenetic and epigenetic mineralization
Several sets of planar and linear structures are described from the very gently folded Karoo strata of the northern-most tectonic zone of the Permo-Triassic Cape Fold Belt. The superposition of these structures reveals a time sequence. Horizontal compression occurred before compaction was complete. After compaction further horizontal compression developed 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 for synsedimentary folding that controlled the sites for erosion channels as well as the direction of sedimentary transport. Exploration efforts for syngenetic and/or fluid controlled epigenetic mineralization in permeable strata of this fluviatile sedimentary sequence should be directed along certain structural lines. © 1994.