Housey Crags Archives - Geology North https://www.geologynorth.uk/tag/housey-crags/ No vestige of a beginning, - no prospect of an end Sat, 19 May 2018 23:02:34 +0000 en-GB hourly 1 https://wordpress.org/?v=6.1.1 https://www.geologynorth.uk/wp-content/uploads/2022/03/Icon-53x53.jpeg Housey Crags Archives - Geology North https://www.geologynorth.uk/tag/housey-crags/ 32 32 Housey and Long Crags https://www.geologynorth.uk/housey-and-long-crags/ Tue, 21 Oct 2014 15:13:54 +0000 http://www.geologynorth.uk/?p=16879 A fine day and we go in search of these magnificent outliers of hornfelsed andesite. At both crags, careful searching reveals a fine-grained pink granitic rock at the base which we interpret as granite chilled against the andesite. The stratification of the altered lava crags follow exactly the same contour as the base terrain which … Continue reading Housey and Long Crags →

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]]> A fine day and we go in search of these magnificent outliers of hornfelsed andesite.
At both crags, careful searching reveals a fine-grained pink granitic rock at the base which we interpret as granite chilled against the andesite.
The stratification of the altered lava crags follow exactly the same contour as the base terrain which is made up of plutonic rock. This supports the idea that these crags were part of the final roof of the magma chamber that remains pretty much in its original position rather than a portion that has fallen into the magma.
(While by no means conclusive, this evidence points away from cauldron subsidence or stoping.) (Couldn’t the stoping process have occurred at a lower level than these portions of roof, leaving them unaffected?)
The space problem in relation to plutons has reared its head.

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