You have to love science, much as you have to love a slightly naughty, slightly incompetent little child when it claims to have worked something out about the world for the first time ever. The study of the history of science may seem a dull and distant cousin to the cutting edge of modern research, but history has many virtues, one of which is to help prevent us having to reinvent forgotten wheels. Researching the history of glaciology for my new book “Glacier” I have encountered many cases where discoveries have been made, written up… and then forgotten, only for the same questions to be asked again a generation later.
In 2001 the Proceedings of the Geologists’ Association included a paper that the authors described as “the first comprehensive description and interpretation of Pleistocene glacigenic deposits exposed in a cliff section at Thurstaston on the Wirral Peninsula, NW England.” It was a splendid paper, and did indeed provide the most comprehensive description and analysis of that site to date. It even referred to previously published literature about the glaciation of the UK from as early as 1860 to set the historical context for the work. However, it didn’t refer to one particular publication from that era: a fairly obscure note published in “The Glacialists’ Magazine” in 1895 under the heading “Notes on the glacial deposits on the Cheshire shore of the Dee Estuary” by Arthur R. Dwerryhouse, which was itself a detailed description and analysis of those same sediments. The 1895 paper seems to have fallen into the great pit of forgotten knowledge.
The 2001 paper set out to address the ongoing debate about whether the sediments were deposited by a land-based glacier or laid down under water, and whether the different sediments in the sequence represented different events or different processes operating within the context of a single event. Dwerryhouse in 1895 had used much the same evidence as the 2001 team, including clast lithological analysis, striations on individual boulders and on boulder pavements, and deformation structures and clast fabrics in the sediments to settle the same argument for a previous generation. He concluded that the sediments were glacial, with the “boulder clay” deposited directly by an ice sheet while the sand and gravel were deposited by streams flowing at the base of that ice sheet. The list below compares extracts from the 2001 publication with extracts from the note published a hundred years earlier:
2001: The sedimentary succession at Thurstaston is best explained by the advance and subsequent recession of a single terrestrially based ice sheet during the Late Devensian. Both the diamictons are interpreted as basal, deformation tills with the interbeds of the sand, gravel and mud lithofacies as indicators of subglacial meltwater flow and ponding.
1895: The boulder clays I attribute, then, to the direct action of an ice sheet, and the gravels and sands to subglacial drainage.
2001 There is no evidence at Thurstaston to suggest a glaciomarine origin for the Late Devensian deglaciation sediments on this margin of the Irish Sea basin.
1895: I cannot see any evidence in the deposits on this shore in favour of the view that the beds were deposited in deep water.
2001: The diamicton lithofacies can be divided into an upper, clast-poor sandy diamicton and multiple units of a lower, clast-rich sandy diamicton.
1895: …two distinct layers of boulder-clay are shown in the cliffs. The lower bed… is sandy and of a bright red colour. The upper bed is… extremely varied in composition, in some places being very gravelly.
2001: (There is a) lack of clearly defined changes in clast lithology through the various lithofacies… Particularly distinctive rocks include the Borrowdale Volcanic Group tuffs, the Ennerdale granophyre and Eskdale granite. …
1895: Both beds contain shell fragments and their boulder contents appear to be similar. The latter consists of Eskdale granite, Buttermere granophyres, Scotch granites, Lake District volcanic rocks…
In a way it is reassuring to know that science can repeat its results in an independent re-study of the same question after a gap of a hundred years. Somehow it is comforting, also, to know that the till at Thurstaston hasn’t changed in that time. And it is astonishing to see how Victorian scientists over a century ago could reach the same conclusions as scientists in the 21st century, and then have their work lost and forgotten. It makes you wonder what else has been lost, and what will happen, over the course of time, to the things we are finding out today.