The BGS Lexicon of Named Rock Units — Result Details

Norwick Hornblendic Schist Type 2

Computer Code: NORH2 Preferred Map Code: SYMBOL
Status Code: Full
Age range: Cambrian Period (E) — Cambrian Period (E)
Lithological Description: A green hornblende-rich schist with an S-tectonite fabric, which commonly has fine closely-spaced feldspar-rich laminations. At Virva, it grades into greenschists of volcanic origin.
Definition of Lower Boundary: A tectonic slice, having a faulted base.
Definition of Upper Boundary: A tectonic slice, having a faulted base.
Thickness: A tectonic slice up to several hundred metres thick.
Geographical Limits: Occur in several locations in Fetlar - most outcrops are of limited extent up to 1 km long and up to several hundred metres wide.
Parent Unit: Shetland Ophiolite Complex (SHOP)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Virva section on NE coast of Fetlar. Flinn, 1993. 
Flinn D. New evidence that the high temperature hornblende-schists below the Shetland ophiolite include basic igneous rocks intruded during obduction of the 'cold' ophiolite. 1993. Scottish Journal of Geology, 29 [2], 159-65. 
Flinn, D, Miller, J A and Roddom, D. 1991. The age of the Norwick hornblendic schists of Unst and Fetlar and the obduction of the Shetland ophiolite. Scottish Journal of Geology, 27 (1), 1-80. 
Read H H. 1934. The metamorphic history of the Unst in the Shetland Islands Quarterly Journal of the Geological Society of London, 90, 637-88. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: