The BGS Lexicon of Named Rock Units — Result Details

Hermod Sandstone Member

Computer Code: HERS Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Eocene Epoch (GE) — Eocene Epoch (GE)
Lithological Description: The Hermod Sandstone Member consists of clean, very fine to medium grained sandstone displaying distinctive 'blocky' log profiles. Thin intercalations of dark grey fissile mudstone are also present.
Definition of Lower Boundary: The base of the Hermod Sandstone Member is taken at a downward change to mudstone, associated with an increase in gamma-ray values and a decrease in sonic velocity. Where the underlying Teal Sandstone Member (Sele unit 1) is thin (e.g. 10/1-1A ), the Hermod Sandstone Member rests on sandy mudstones that probably represent unit S2b (refer to Sele Formation); where the Teal Sandstone Member is thicker (e.g. 10/1-3), only a thin, high-gamma mudstone separates it from the underlying Teal Sandstone Member, possibly reflecting condensation over a mounded Teal Sandstone topography.
Definition of Upper Boundary: The top of the Hermod Sandstone Member is taken at a downward change from mudstone to sandstone, associated with a decrease in gamma-ray values and an increase in velocity.
Thickness: It is generally less than 100 m thick in the UK sector.
Geographical Limits: The Hermod Sandstone Member is restricted to the North Viking Graben.
Parent Unit: Sele Formation (SELE)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Norwegian Sector North Sea well N25/2-6 (Isaksen & Tonstad 1989, fig.56): 2221-2361 m (7287-7746 ft) below KB. This section may include representatives of the Teal Sandstone Member. 
Reference Section  North Sea well 10/1-1A: 2126-2212 m (6975-7257 ft). 
Reference Section  North Sea well 10/1-3: 2073-2178 m (6801-7146 ft). 
Reference(s):
Knox, R W O'B and Holloway, S. 1992. 1. Paleogene of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
Isaksen, D and Tonstad, K. 1989. A revised Cretaceous and Tertiary lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No.5 
Mudge, D C and Copestake, P. 1992. Lower Palaeogene stratigraphy of the northern North Sea.Marine and Petroleum Geology,9,287-301. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable