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Soft‐sediment deformation of sandstone related to the Dwyka glaciation in South Africa
Author(s) -
BELL C. M.
Publication year - 1981
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.1981.tb01683.x
Subject(s) - lineation , geology , slumping , glacial period , glacier , deformation (meteorology) , geomorphology , carboniferous , geochemistry , paleontology , oceanography , structural basin , tectonics
Sandstones of the uppermost Witteberg Group in the Cape fold belt of South Africa exhibit unusual and distinctive soft‐sediment deformation structures. These structures include folds, axial planar cleavage and micro‐fold lineations. Interfering fold patterns and intersecting sets of lineations are indicative of repeated deformation. The sandstones are immediately overlain by glacial and proglacial sediments of the Carboniferous Dwyka Group, indicating that the deformation was related to glaciation. Possible environments of deformation include: (a) subglacial dragging of unconsolidated material, (b) subaqueous slumping beyond the limit of floating ice, and (c) englacial deformation of material incorporated by freezing into the base of the glacier.