Millyeat Member
Millyeat Member (MYTB), Carboniferous, Northern England Province
Millyeat Member is a member of the Whitehaven Sandstone Formation and part of the Warwickshire Group
Name
See Akhurst et al. (1997[1]); also Brockbank (1891[2]); Eastwood et al. (1931[3]); Jones (1993[4]). In the former name ‘Millyeat Beds Member’ the term ‘Beds’ has now been abandoned.
Lithology
A thick heterogeneous, dominantly red succession of purple–red mudstone, with subsidiary sandstone and siltstone, and minor ‘marl’, thin coals and thin beds of limestone with Spirobis sp.
Genetic interpretation
The member was deposited in interdistributary bay or lacustrine environments with minor river channels (Akhurst et al., 1997[1]). The reddening was either primary or early diagenetic.
Stratotype
The type section is the Frizington Hall Borehole (BGS Registration Number NY01NW/174) (NY 0189 1710) from 12.8 to 155 m depth. A reference section is the Millyeat Borehole (BGS Registration Number NY01NW/175) (NY 023 178) from about 7.5 to 158 m depth.
Lower and upper boundaries
The base of the unit is the top of the highest major channel sandstone unit in the Bransty Cliff Sandstone Member (Figure 14, Column 1).
The upper boundary of the member is the sub-Permian unconformity, which is overlain by the coarse, poorly bedded, poorly to moderately sorted, generally massive, matrix or clast-supported, typically pebble-grade, breccias of the Permian Brockram (Appleby Group).
Thickness
Up to 180 m maximum.
Distribution and regional correlation
West Cumbria Coalfield.
Age
Bolsovian (Westphalian C) to Asturian (Westphalian D).
References
- ↑ 1.0 1.1 Akhurst, M C, Chadwick, R A, Holliday, D W, McCormac, M, McMillan, A A, Millward, D, and Young, B.1997.Geology of the west Cumbria district.Memoir of the British Geological Survey, Sheets 28, 37 and 47 (England and Wales).
- ↑ Brockbank, W.1891.On the occurrence of the Permian, Spirorbis limestones, and Upper Coal Measures at Frizington Hall in the Whitehaven district.Memoir of the Proceedings of the Manchester Literary and Philosophical Society, Vol. 4, 418–426.
- ↑ Eastwood, T, Dixon, E E L, Hollingsworth, S, and Smith, B.1931.The geology of the Whitehaven and Workington District.Memoir of the Geological Survey, Sheet 28 (England and Wales).
- ↑ Jones, N S.1993.Stratigraphical and sedimentological characteristics of the ‘Whitehaven Sandstone Series’, Westphalian C, West Cumbria coalfield.British Geological Survey Technical Report, WH/93/102R.