Mourne Geology & Coastal Processes Glasdrumman.

Description

Coords: 54.12959 -5.88994 Map: http://binged.it/1RKHTZT Glassdrumman beach exposes very interesting & unusual rocks types, some of which still spark debate on how they formed. They are typically alternating layers of mudstone & sandstone with some original sedimentary features from 430Ma & also Mourne granite emplacement-related deformation form 57Ma such as 'Boudinage' and evidence of melting. At a different orientation to the metasediments, an unusual 15m thick band of harder rock stands proud. A pink granite with large feldspars (prophyry) is bounded on each side by a thinner band of black basalt. The contact between the metasediments & the basalt & between the basalt & the granite is mainly very sharp but there are 'blobs' of the basaltic material included in the granitic material in places. The 'blobs' have both rounded & angular rims. The whole structure is described as a cone-sheet which encircles the main Mourne granites & is thought to be the same age as them. Model © Conor Graham 2015