Old Red Group OR


Premise In the Dutch sector of the North Sea, continental Devonian deposits have been encountered in a small number of wells only on and around the Mid North Sea High and the Elbow Spit High. In combination with information from wells drilled in the UK sector, a better understanding of the stratigraphy could be achieved. In part, the British stratigraphic nomenclature (Cameron (1993a) ; Cameron (1993b) ) has been adopted for the Netherlands.
Derivatio nominis Named after the continental Devonian deposits, known in the UK as Old Red Sandstone.
Type section Location map See figure (pdf)
  Well A17-01 (pdf)
  Location N 55°01’11.4
E 03°39’29.4
  Depth 2084 to 3013 m
  Length 929 m along hole
Additional section Location map See figure (pdf)
  Well E06-01 (pdf)
  Location N 54°46’09.2
  Depth 2755 to 3200 m
  Length 445 m along hole
Definition A group of sandstones, siltstones and claystones with minor thin dolomite intercalations in its lower part. Red and red-brown colours prevail in the fine-grained intervals in most of the group. Acid volcanic extrusives occur in the lower and middle part.
Upper Boundary It is overlain conformably by the Farne Group, which is characterized by the occurrence of limestone beds. Locally the group is overlain unconformably by younger formations (Rotliegend to Chalk Groups) as a result of severe later erosion.
Lower Boundary The group rests nonconformably on the Caledonian basement of the Elbow Spit High. In well A17-0 (see pdf) this consists of a grey and pinkish, very coarse-crystalline granite.
Correlation The Old Red Group can be equated largely to the Upper Old Red Group in the United Kingdom.
Distribution Only a few wells in the Netherlands have reached the Old Red Group, so little information is available on its areal distribution. Regional studies, however, indicate that this group has a wide distribution in the central and northern North Sea area, as described by Cameron (1993a) ; Cameron (1993b) )
Age The age of the group, as far as it is known from the Elbow Spit High area, ranges from Givetian/Frasnian to Tournaisian (Courceyan).
Depositional Setting The sediments of the group were deposited in a continental setting. The sandstones and red and grey claystones are fluvial-channel and floodplain deposits. The grey, dolomitic claystones suggest deposition in limnic conditions. Active acid volcanism occurred locally.
  ORTP Tayport Formation
  ORBU Buchan Formation
  ORPA Patch Formation
References See References Devonian and Lower Carboniferous

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