Ieper Member NLFFY


Premise Originally defined by NAM and RGD (1980) . The lithological affix has been deleted here. In Belgian lithostratigraphy the name Ieper is used to designate a group Marechal and Laga (1988) , which is approximately the equivalent of the Dutch Ieper Member.
Derivatio nominis The name refers to the Belgian town of Ieper in western Flandres.
Type section Location map See figure (pdf)
  Well Dongen-1 (pdf)
  Location N 51°37'37.0
E 04°4'48.2
  Depth 844 to 985 m
  Length 141 m along hole
  Reference NAM and RGD (1980)
Additional section Location map See figure (pdf)
  Well L02-04 (pdf)
  Location N 53°51'22.2
E 04°38'59.2
  Depth 1099 to 1524 m
  Length 425 m along hole
  Reference NAM and RGD (1980)
Definition Generally soft, tough and sticky to hardened and friable clay. A subdivision into two parts can be recognised regionally. The lower part is characterised by its brown-grey colour, tending to beige or red-brown locally. The unit contains pyrite, is non-calcareous, and coalified plant remains are locally present at the base (possibly reworked material). The upper two-thirds have a characteristic green-grey colour. It has a sandy upper part with a number of larger sandstone intercalations and it is somewhat calcareous and glauconitic. Along the palaeo-coastline the clays are silty with some sand stringers, which become less common distally.
Upper Boundary The upper boundary with the overlying Brussels Sandstone Member is very variable. Regionally there is an unambiguous boundary between the clays and the sands and sandstones. However, near the palaeo-coastline and on palaeo-highs in the southern and eastern part of the basin the boundary is gradual and complex, because, locally, different parts of the succession are missing as a result of various phases of erosion and/or non-deposition. The nature of these breaks in sedimentation is not well documented.
Lower Boundary The lower boundary with the Basal Dongen Sand Member or the Basal Dongen Tuffite Member generally shows as a clear transition to the clays of the Ieper Member.
Distribution The member is present throughout most of the Netherlands on- and offshore area, with the exception of southern Limburg and a zone of erosion on the ‘Southern Early Tertiary High’.
Age Early Eocene (Ypresian). The unit has yielded nannoplankton from zones NP 10 to NP 13. Large parts of the member are barren of nannofossils, and the NP 10 zone has only been identified north of the Mid Netherlands Fault Zone. It comprises foraminiferal zone FI and the lower part of the FH2-Zone.
Depositional Setting Deposited in a clearly open-marine environment.
Sequence Stratigraphy The unit comprises cycles TA 2.4 to TA 2.9. Two minor drops in sea level may correspond to the somewhat siltier intervals in the Ieper member. A more relevant drop in cycle TA 2.7 is expressed by a sandier interval.
References See References Tertiary

Van Adrichem Boogaert, H.A. & Kouwe, W.F.P., 1993-1997. [Stratigraphic unit]. In: Stratigraphic Nomenclature of the Netherlands.
Retrieved [Datum] from [url].