Geology and Scenery of the Lake District

At a time when the hotels in the lake district was beginning to attract visitors in ever increasing numbers in the early years of the nineteenth century, it was perhaps both fortuitous and appropriate that a local guide, Jonathan Otley, should publish the first scientific account of its geology in 1820. From his house at Brow Top in Keswick, where he carried on a small business as a watchmaker, he would occa-sionally take time off to wander across the fells or by the lake edge noting the various types of rocks and the way in which they influenced the scenery. This familiarity with the district and his fund of local knowledge soon led to a reputa-tion as a guide and scientific authority. Both George Airy, the Astronomer Royal, and Adam Sedgwick, the Professor of Geology at Cambridge, sought his views and advice.

Sedgwick, in particular, born not far away at Dent on the Lakeland fringe, became a close friend of Otley and on various occasions paid tribute to his pioneer work on the geology of the area.

Shortly before Oley's death in 1855 Sedgwick wrote of him as 'the teacher on all we know of the country'. He had good reason to be grateful for, although his relationship was that of able professional to gifted amateur, he was able to build upon the founda¬tions of geological knowledge so painstakingly worked out by the Keswick guide.
Jonathan Otley was fifty-five before he published the results of his geological observations.

As a true amateur he chose the pages of the local Lonsdale Magazine to expound his views in a short paper with the title 'Remarks on the succession of rocks in the District of the Lakes'. In this account he set out, in his own clear informative style, the basic tripartite division of the slatey rocks of the central core area. In the north, forming Skiddaw, Saddleback and Grasmoor, he recog¬nized a variable group to which he gave the name clay slate.

Not only did he suggest that these were the lowest beds and therefore the earliest rocks of the whole Lake District, his knowledge of the area was such that he noted that a similar outcrop formed the mountain of Black Coombe, in the extreme southwest. His middle group of rocks, the Greenstone, in his own words 'comprehends the mountains of Eskdale, Was dale, Ennerdale, Borrowdale, Langdale, Grasmere, Patterdale, Martindale, Mardale and some adjacent plains, including the two highest mountains of the district, Scafell and Helvellyn, as well as the Old Man of Coniston'. Today this group, lying athwart the highest central part of the Lake District as Otley noted, is referred to as the Borrowdale Volcanic Series, to take account of their very vari¬able nature.

The third division, the most variable of all, consists of beds of lime¬stone, shale, slate and flags,  and was grouped by Otley as the Greywacke forma¬tion. In its distribution it is restricted to the southern Lake District where it forms the lower plateau country bordering on Morecambe Bay. At its base is the thin but persistent bed of Coniston Limestone, which Otley traced across country for forty miles from Broughtont northeastwards across the head of Windermere and thence through the upper ends of the vales of Trout beck, Kent mere and Long Sleddale . It is a tribute to his observant eye and willingness to explore the remote corners of the southeastern fell country, that enabled him to map the outcrop of this thin though important bed which divided his Greywacke formation from the underlying volcanic rocks.

Much of the content of this preliminary essay in the Lonsdale Magazine was later incorporated by Otley in his guide book for tourists, first published in 1823. This ran to no fewer than eight editions, the last in 1849. In the intervening period Sedgwick was carefully adding the details within the framework pro¬vided by Otley. Some of the results were published in a series of papers which he prepared for the newly founded Geological Society of London between 1831 and 1855. Perhaps better known is the account which was written by Sedgwick for Wordsworth's Complete Guide to the Lakes published in 1842.

This took the form of three letters describing the various rock types present and the way in which they influenced the scenery. This latter aspect had been foremost in Otley's mind when he wrote of the Borrowdale Volcanic Series that 'all our fine towering crags belong to it and most of the cascades among the lakes fall over it. There are indeed some lofty precipices in the first division (the Skiddaw Slates), but owing to the shivery and crumbling nature of the rock, they present none of the bold colossal features which are exhibited in this.'