Macgregor Marine Bands
Macgregor Marine Bands, Carboniferous, Midland Valley of Scotland
The Macgregor Marine Bands are part of the Strathclyde Group.
The Macgregor Marine Bands were named by Wilson (1974)[1] in the Lothians, but appear to be best developed in east Fife, where they are probably all found within the Pittenweem Formation. At least 5 marine beds exist in the partial type sections of the formation (Table 3) and comprise c. 6% of its thickness, which here may be 260 m. They represent the first fully marine incursions to affect east central Scotland in Carboniferous times (see Wilson, 1989, Figure 7), and contain rich and distinctive faunas. Whilst the faunas are largely facies controlled (Chisholm et al., 1989[2]; Wilson, 1974[1] , Figure 3), all the major fossil groups except trilobites are represented. Corals are scarce. Punctospirifer sabricosta, Pteronites angustatus and Streblopteria redesdalensis are thought to be diagnostic of the Macgregor Marine Bands (see Wilson, 1974[1]; 1989)[3].
Correlation
The Macgregor Marine Bands are recognisable as a group but no single marine bed can be correlated over an appreciable distance with confidence (Wilson, 1974[1]). The strata including the Macgregor Marine Bands show a large degree of lateral variation, and hence it cannot be confirmed that the marine band at the base of the Aberlady Formation in the Spilmersford Borehole is the same as that in the Skateraw Borehole or the Cove shore section. However, on the basis of macrofaunal and miospore evidence, Wilson (1974, p.42[1]) correlated the Macgregor Marine Bands in the Spilmersford Borehole (as a group in the basal 47 m of what is now the Aberlady Formation) with the Cove marine bands at Cove Harbour, Thornton Burn and the BGS Borehole at Skateraw, and with the Lamberton Limestone of the Burnmouth district. The Lamberton Limestone was correlated with the Dun Limestone of Northumberland on general lithological grounds by Fowler (1926[4]; see also Greig, 1988, p.42[5]).
References
- ↑ 1.0 1.1 1.2 1.3 1.4 WILSON, R B. 1974. A study of the Dinantian marine faunas of south-east Scotland. Bulletin of the Geological Survey of Great Britain, Vol. 46, 35–65.
- ↑ CHISHOLM, J I, MCADAM, A D, and BRAND, P J. 1989. Lithostratigraphical classification of Upper Devonian and Lower Carboniferous rocks in the Lothians. British Geological Survey Technical Report, WA/89/26.
- ↑ WILSON, R B. 1989. A study of the Dinantian marine macrofossils of central Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, Vol. 80, 91–126.
- ↑ FOWLER, A. 1926. The geology of Berwick-on-Tweed, Norham and Scremerston. Memoir of the Geological Survey of Great Britain, Sheets 1 and 2 (England).
- ↑ GREIG, D C. 1988. Geology of the Eyemouth District. Memoir of the British Geological Survey, Sheet 34 (Scotland). JACKSON, D I, and 5 others. 1995. United Kingdom offshore regional report: the geology of the Irish Sea. (London: HMSO for the British Geological Survey.)