Borrowdale volcanics & Crinkle Crags
Cumbria, England
Borrowdale is a valley in the English Lake District in the Borough of Allerdale in Cumbria. The valley lends its name to the Borrowdale Volcanic Group, which make up most of the mountains at the head of Borrowdale including Scafell Pike.
The Crinkle Crags are a classic and complex area of volcanic geology, dating from the late Ordovician. The Borrowdale volcanic group are a series of andesitic lavas and pyroclastic rocks, erupted from an arc of volcanoes that had developed above an active subduction zone - in this case, along the southern margin of the Iapetus ocean.
The complexities of the volcanic geology of arc volcanoes - which show rapid variations in lithofacies and depositional environments, and post-depositional modification ranging from redeposition to caldera-formation - means that much of the detail of the eruptive history has only been worked out within the past couple of decades.
Text courtesy of D.L. Pyle
Further reading
BRANNEY, M.J. (2006). The Borrowdale Volcanic Group and Ordovician continental arc volcanism in northern England In: Brenchley, P.J., Rawson, P.F. (eds)
The Geology of England and Wales. 2nd Edition The Geological Society, London: 113-122
Images (top to bottom):
- Crinkle Crags at sunset © D.L. Pyle
- Fell Runners descending Crinkle Crags © Mick Garratt (Source Geograph.org.uk) Creative Commons Attribution-ShareAlike 2.0 license.
October 13 - 21
Theme: 'Earth Science in our lives'