The structural and diagenetic evolution of injected sandstones: examples from the Kimmeridgian of NE Scotland

Jonk, R., Duranti, D., Parnell, J., Hurst, A. and Fallick, A.E. (2003) The structural and diagenetic evolution of injected sandstones: examples from the Kimmeridgian of NE Scotland. Journal of the Geological Society, 160(6), pp. 881-894.



Publisher's URL:


Abstract: Injected sandstones occurring in the Kimmeridgian of NE Scotland along the bounding Great Glen and Helmsdale faults formed when basinal fluids moved upward along the fault zones, fluidizing Oxfordian sands encountered at shallow depth and injecting them into overlying Kimmeridgian strata. The orientation of dykes, in addition to coeval faults and fractures, was controlled by a stress state related to dextral strike-slip along the bounding fault zones. Diagenetic studies of cements allow the reconstruction of the fluid flow history. The origin of deformation bands in sandstone dykes and sills was related to the contraction of the host-rocks against dyke and sill walls following the initial stage of fluidized flow, and these deformation bands are the earliest diagenetic imprint. Early non-ferroan calcite precipitated in injection structures at temperatures between 70 and 100 8C, indicating that it precipitated from relatively hot basinal fluids that drove injection. Coeval calcite-filled fractures show similar temperatures, suggesting that relatively hot fluids were responsible for calcite precipitation in any permeable pathway created by dextral simple shear along the faults. During progressive burial, percolating sea water was responsible for completely cementing the still relatively porous injected sandstones with a second generation of ferroan calcite, which contains fluid inclusions with homogenization temperatures below 50 8C. During this phase, depositional host sandstones were also cemented.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Fallick, Professor Anthony
Authors: Jonk, R., Duranti, D., Parnell, J., Hurst, A., and Fallick, A.E.
Subjects:Q Science > QE Geology
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Journal of the Geological Society
Publisher:Geological Society of London
Copyright Holders:© Copyright The Geological Society of London
First Published:First published in Journal of the Geological Society 160(6)881-894
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher.

University Staff: Request a correction | Enlighten Editors: Update this record