Abstract
Two of the most far-reaching conclusions of Davies and Cave (1976) are: (1) The slaty cleavage in the Lower Palaeozoic rocks of mid-Wales was established while the sediment was still soft and unconsolidated. (2) The cleavage developed by mechanical rotation of clay. flakes during shearing when the clays were in the condition of quick clays. Most of their evidence is based on field observations together with stereo-scan work on cleaved argillaceous rocks. I have recently made a detailed study of cleavage in a coarse greywacke bed around a fold from Cwm Tydi (NG-SN359581) Cardiganshire. The fold is exposed on coastal outcrops of the Aberystwyth Grits described by Price (1962). The cleavage is axial planar to the fold and curves as it passes through the graded greywacke bed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
