𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Pseudofaults resulting from compartmentalized Liesegang bands: update

✍ Scribed by Earle F. McBride


Book ID
104463130
Publisher
John Wiley and Sons
Year
2003
Tongue
English
Weight
473 KB
Volume
50
Category
Article
ISSN
1469-3496

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✦ Synopsis


Abstract Liesegang bands with apparent offset along fractures are common in some calcisiltite beds. Thin sections show, however, that primary laminations are not offset along the fractures. Following the development of fracture sets in the calcisiltite, the fractures were cemented by calcite. This formed polyhedral compartments of low‐permeability calcisiltite bounded by impermeable walls of calcite. Liesegang bands formed when oxygen in ground water diffused into polyhedra containing soluble ferrous iron in pore water. Each joint‐bounded polyhedral compartment behaved as an independent diffusion cell. Liesegang bands with nearly the same pattern and thickness tended to develop in adjacent compartments, but not at the same stratigraphic level; this resulted in the formation of pseudofaults.