The Ukrainian water-god of the Castleford coal

I popped into Henry Moore’s alma mater last week, to talk to the Year 9 geography students about palaeontology and Geoscience for the Future. In preparing my talk, I was curious to know what rocks were beneath the school.

On consulting the British Geological Survey map, I was unsurprised to learn that the bedrock was Carboniferous. This was Castleford, a coal-mining town, after all. However, I was delighted to see a dashed black M-line curving across the map. A marine band in the Coal Measures, running under the buildings and the playing fields. The school had its own fossil horizon!

After my visit, I decided to dig a little deeper. What kinds of fossils were in the marine band, and had any ever been unearthed near the school? In doing so, I found myself embarking accidentally on a voyage of palaeo-geography, geopolitics and mythology.

So, what kind of fossil horizon was it? Well, the coals are all fossil horizons, of course, but the marine bands are palaeontologically special. They represent periods of higher sea-level, when the coal swamps were submerged by brackish or – occasionally – fully marine waters. This table provides a summary.

In the mostly brackish marine bands, fossil fish and lingulid brachiopods turn up, but with salty seas came salty sea creatures, the most distinctive of which were goniatites.

(If you’re not familiar with these splendid molluscs, may I recommend this excellent video?)

Now, I could see from the geological map that there were three coal beds above the marine band, before the rocks turned Permian at Heald Wood. I needed to cross-check the map with its stratigraphic column, and work out where exactly in the Pennine Middle Coal Measures it was.

This required one of my very favourite things – hunting down obscure geological literature!

Searching for Castleford coal stratigraphy on Google Scholar, I figured that British Geological Survey reports from the 1980s and 1990s were likely to be my greatest help. Giles (1987) and Wallace et al. (1990) quickly came up trumps, and indicated that the scholarly fossil horizon was likely to be the Aegiranum Marine Band.

From Wallace et al. (1990, p. 51), I was pleased to read that this was a special Measures fossil horizon, as it represented the “one instance…[when] marine conditions may have briefly prevailed, on the evidence of the presence of the eponymous goniatite, Donetzoceras aegiranum (Schmidt).”

Apparently, the bed “contains a rich fauna…mainly in calcareous nodules and layers,” with specimens of D. aegiranum having been found in the 1980s on Sewerbridge Lane, west of the village of Ackton. Keen readers were referred to a 90-year-old paper: EDWARDS, W. 1932. The Mansfield Marine Band in the Castleford District. Transactions of the Leeds Geological Association, Vol. 5, 86-92.

Clearly I should have sought out Edwards’ seminal work next, but I didn’t, because I was distracted by the goniatite’s name. Did ‘Donetzoceras‘ indicate it came from Donetsk, in Ukraine? And was ‘aegiranum‘ linked to the Norse personification of the sea?

The answers are ‘yes’ and ‘possibly’. Schmidt’s (1925) paper was German, and I don’t think my 30 year-old GCSE German will be of much palaeontological use. However, the study by Saunders et al. (1979) confirms that Donetzoceras was coined by Librovitch in 1946, with the type species (Donetzoceras donetzense) being from “the village of Khartsiskoe, Donets Basin, Ukrainia, USSR.” I think this may be the present-day town of Khartsyzk, east of Donetsk.

“Donetzoceras aegiranum is a characteristic taxon of the Aegiranum marine band throughout Europe,” continue Saunders and colleagues (1979, p. 1140). “The location of the primary types of Donetzoceras aegiranum is unknown; they may have been lost or destroyed during World War II.

“[However,] numerous well-preserved reference specimens…are available in the Palaeontological Museum, Institute of Geological Science, Leeds.”

Conflict and Ukraine were not topics I was expecting to discuss here, but geology and geography underpin everything. And suddenly, thanks to sea-level rise more than 300 million years ago, a small sea creature connects a school in West Yorkshire to eastern Europe.