Chalk Group Lithostratigraphy: Northern England - Chalk Hill Marls
A group of three closely spaced (occupying a c. 0.25 m interval) thin marls (5-10 mm thick) that mark the top of the Mytiloides-rich shell detrital chalk of the basal Welton Chalk Formation, and are occasionally associated with small (c. 10 mm) rounded, nodular flints (representing the lowest flints recorded in the Welton Chalk Formation) (Gaunt et al., 1992). The marls are named after Chalk Hill which formerly occupied the site of Melton Ross Quarry [TA 077 110], and probably equate with the Gun Gardens Main Marl of Mortimore (1986a) (Gaunt et al., 1992), which marks the top of the Holywell Nodular Chalk in southern England. Comminuted inoceramid shell, probably of Mytiloides, occurs in the lowest of the three marls (Gaunt et al., 1992).
Macrofossil Biozonation: top Mytiloides spp. Zone
Correlation: see Correlation with other UK Chalk Group successions
References
GAUNT, G D, FLETCHER, T P & WOOD, C J. 1992. Geology of the country around Kingston-upon-Hull and Brigg. Memoir of the British Geological Survey.
See: Gun Gardens Main Marl, Holywell Nodular Chalk