Stylolite-Controlled Layering in an Homogeneous Limestone: Pseudo-Bedding Produced by Burial Diagenesis
- Maurice E. Tucker2 and
- Robin G. C. Bathurst3
Published Online: 29 APR 2009
Copyright © 1990 The International Association of Sedimentologists
How to Cite
Simpson, J. (1990) Stylolite-Controlled Layering in an Homogeneous Limestone: Pseudo-Bedding Produced by Burial Diagenesis, in Carbonate Diagenesis (eds M. E. Tucker and R. G. C. Bathurst), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304510.ch27
Department of Geological Sciences, University of Durham, UK
Derwen Deg Fawr, Llanfair DC, Ruthin, Clwyd, North Wales, UK
- Published Online: 29 APR 2009
- Published Print: 21 AUG 1990
Print ISBN: 9780632029389
Online ISBN: 9781444304510
- stylolite-controlled layering in homogeneous limestone - pseudo-bedding;
- Lower Carboniferous High Tor Limestone of Gower, showing diagenetic layering;
- recognition of bedding -primary stage of facies analysis;
- concept of pressure-dissolution-controlled layering;
- coral colony distribution
It is often assumed that layering in many shelf and platform limestones at weathered outcrop is always bedding: the layers always beds, and the surfaces always bedding planes. Recognition of bedding is fundamental to facies and basin analysis.
Examination of part of the Lower Carboniferous High Tor Limestone of the Gower, South Wales, shows that a totally diagenetic layering (pseudo-bedding) resembling, and parallel to primary depositional layering (true bedding), has been produced by the generation of parallel, more or less evenly-spaced stylolite surfaces during burial diagenesis. These stylolite surfaces are picked out by weathering at outcrop and resemble bedding planes. Evidence that the stylolite surfaces do not mark original bedding planes includes: a cross-cutting relationship of a stylolite surface to a primary bedding surface; lack of lithological change across, or sedimentary structures associated with, a stylolite surface; original bedding that is not coincident with stylolite surfaces and has not suffered pressure-dissolution; and lack of sedimentological evidence that the layers defined by the stylolite surfaces are true primary depositional beds. The generation of parallel and more or less evenly-spaced stylolite surfaces could be explained by a mathematical-kinetic model based on the relationship between pressure-dissolution, diffusion, and reprecipitation.
Recognition of true bedding depends upon presence of lithological changes and/or sedimentary structures. It is suggested that pseudo-bedding could be confused with true bedding in some open platform/ shelf lagoon facies where lithological changes or sedimentary structures are scarce or absent.