The information on this page is a summary description.
The full formal description is available here: Cimetière de Grand-Manil Formation
Abbreviation
Parent unit
Child units
Lithological description
The formation shows faintly stratified greenish-grey to often olive-green slate (mudstone to siltstone). Slates with a more silty grainsize and pluricentimetric sequences of planar, oblique and convolute laminations are frequently observed and are interpreted as very distal turbidites of Bouma type. In outcrop, weathered and oxidized nodules parallel to the bedding are also frequently observed (Debacker et al., 2011 Plate 1 photos D to H).
Age
No macrofossils and no microfossil have yet been investigated. Based on its geometrical position between the Cheneyan (lower Katian) Bornival Formation and the lower Onnian (middle Katian) Huet Formation , this formation should be placed in the lower half of the Streffordian, mid Katian Stage (Herbosch & Verniers, 2014 Figs. 2, 3). A biostratigraphical hiatus already recognized at this level by Verniers et al. (2001) was confirmed by Vanmeirhaeghe (2006), who emphasized the strongly differing chitinozoan assemblages of the Huet Formation compared to those in the Ittre and Bornival formations.
Thickness
Its thickness is estimated at about 100 m. The upper and lower contacts have not yet been observed.
Area of occurrence
The formation poorly crops out in the Orneau valley and estimated to occur also in the Sennette valley near the location of the ruined castle of Fauquez (Debacker et al., 2011).
Type locality
No stratotype could be designated but discontinuous small outcrops occur around Grand-Manil, in the Orneau valley. The best outcrops are along a path to the NW corner of the cemetery (Herbosch, 2005 Fig. 4 outcrop number 3, 5, 6; Herbosch & Verniers, 2014 Fig. 7 outcrop A).
Alternative names
Authors
Herbosch, A. & Verniers, J.
Date
01/02/2017
Cite as
Herbosch, A. & Verniers, J., 2017. The Cimetière de Grand-Manil Formation, 01/02/2017. National Commission for Stratigraphy Belgium. https://ncs.naturalsciences.be/lithostratigraphy/Cimetiere-de-Grand-Manil-Formation
