The stratigraphy and tectonics of the Skiddaw slates and the relationship of the overlying borrowdale volcanic series in part of the Lake District

The hornfelsed Skiddaw Slates in the River Caldew, Cumberland, exhibit one of the best displayed sets of folds in the country. Patterns resulting from an analysis of these folds and the structures on the valley sides, indicate that the rocks have suffered several phases of deformation. Evidence is produced to suggest that folding was initiated during the pre-Bala movements, and re-folding occurred during the main end-Silurian orogeny. During the end-Silurian movements, folding due to collapse under gravity also occurred.

Structures of the Skiddaw Slates in the Caldew Valley, Cumberland

Roberts

1971

The structure of the Skiddaw Slates in the Blencathra‐Mungrisdale area, Cumbria

Roberts¹

1977

Four phases of deformation (Dl-D4) and a ubiquitous non-tectonic bedding-cleavage are described. D1 structures are gravity collapse folds without an associated cleavage, formed before the extrusion of the Borrowdale Volcanics. Pre-Bala folds recognised in the Volcanics are not readily observable in the Slates on a small scale. but may be present on a wider aspect. D2-D4folds and cleavages are end-Silurian structures, the result of the main closure of the Lake District Geosyncline during the Caledonian Orogeny. D2 is the result of crustal shortening and is closely related in time to the emplacement of the Skiddaw Granite; D3 resulted from vertical shortening in conjunction with the intrusion of the Lake District Batholith; and D4 resulted from postgranite shortening of the existing fold axes. A correlation of the history of deformation with those of other areas is also suggested.

Lower Palaeozoic lithostratigraphical classification in the English Lake District

Moseley

1984

In the English Lake District lithostratigraphical classification has not kept pace with either the international and national codes or the code of the Geological Society (Holland cr ul. 1978). Probelms arise, firstly, from acceptance by several of those working in the area, of terms used in by-gone days, such as 'Borrowdale Volcanic Series', and secondly, and more importantly, because individuals have specialized on certain parts of the sequence (the Skiddaw Slates, the Coniston Limestone, etc.), and have erected classifications for these rocks without reference to other parts of the succession. These classifications are examined and modified in such a way that the lithostratigraphical subdivisions are consistent for the whole of the Lower Palaeozoic sequence of the Lake District, and also relate to the international code as it is applied in other regions. The basic Lake District stratigraphical terminology of the last century is, however, retained in all its essentials.