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The Black Band Member
by Mike Horne FGS
The Black Band Member consists of a series of chalks, marls and clays at the base of the Melton Formation - Upper Cretaceous Chalk of East Yorkshire and North Lincolnshire.
A generalised sequence consists of an erosion surface at the base; followed by nodular chalk with marl (some of the nodules may be coated with glauconite; nests of Terebratulid brachiopods have been found); followed by a khaki coloured marl rich in microfossils; a grey marl merging into a bioturbated black laminated clay conaining fish scales but few microfossils; followed by a grey marl; then a cream coloured marl that becomes increasingly chalky.
There are though some exposures of a thicker sequence showing multiple dark clays. One of these unusual Black Band sections is near Goodmanham. The Sequence at Melton Ross has been described by Paul Hildreth in Humberside Geologist.
Click here for a comparison of the Black Band Member exposures.
It is thought to represent a worldwide anoxic event, in which rising sea level caused deeper anoxic waters to flood onto the shallower sheld sea causing a mass extinction. Click here for the conventional explanation of Oceanic Anoxic Event no. 2
