The BGS Lexicon of Named Rock Units — Result Details

Melby Sandstone Formation

Computer Code: MYF Preferred Map Code: MSa
Status Code: Full
Age range: Eifelian Age (DI) — Givetian Age (DV)
Lithological Description: Sandstone, siltstone and mudstone, generally flaggy, buff and red; two pale grey siltstone units (Melby Fish Beds) near the base of the sequence.
Definition of Lower Boundary: On the Walls Peninsula, faulted contact along the Melby Fault, against the Sandness Formation. However, basal relationships are complex and the sandstone may locally be disconformable on the lower leaf of the Melby Rhyolite Member [see also boundary definitions of Papa Stour Volcanic Formation].
Definition of Upper Boundary: Highest unit in the local sequence: top contact not preserved.
Thickness: c.760m on the Walls Peninsula.
Geographical Limits: Northwest portion of the Walls Peninsula, Mainland Shetland, northwest of Lerwick. May also extend onto the offshore islands of Foula (but may not be the same unit) and Papa Stour, c.40km northwest of Lerwick.
Parent Unit: St Magnus Bay Group (STMA)
Previous Name(s): Melby Formation (-2952)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Northwest portion of the Walls Peninsula, Mainland Shetland, some 35km northwest of Lerwick. The whole sequence is exposed around the coast of the melby Peninsula, which is a part of the Walls Peninsula. [see Mykura and Phemister, 1976, chapter 10] 
Reference(s):
Mykura W and Phemister J. 1976. Geology of Western Shetland Memoirs of the Geological Survey of Great Britain, Scotland [Explanation of One-inch Geological Sheet 127 and parts of 125, 126 and 128] 
Mykura W, 1976 British Regional Geology: Orkney and Shetland (HMSO, Edinburgh).] 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S127