The Geology of Holy Island


Key Details



Join Karl Egeland-Eriksen to explore the fascinating geology of Lindisfarne.

Event leads: Karl Egeland-Eriksen

Event length: 1 session, Saturday, 10.30am-4.00 pm

Event cost: Free to NHSN members

This trip will be run in accordance with government guidance on covid-19.

Probably the most prominent feature on Lindisfarne is the castle that sits atop an outcrop of the Whin Sill. A ‘sill’ is an igneous sheet intrusion that has intruded between older layers of rock and is concordant, meaning that a sill does not cut across pre-existing rock beds. The Whin Sill is the ‘type’ sill after which all igneous sills in the world are named. It does, however, not always occupy the same level in the rocks but steps up to higher levels in places. These steps produce Whin dykes which do cut across pre-existing rock beds.

Lindisfarne Castle stands on one of these Whin dykes (whereas Bamburgh Castle is on the Sill proper). The line of the dyke can be seen from beyond the castle, looking west, forming ‘The Heugh’ and the enigmatic St. Cuthbert’s Isle (even harder to get onto than Lindisfarne!).

The contact with the sedimentary strata can be seen to the south of the Heugh where fossiliferous limestone is ‘baked’ onto the wall of the Sill. Further exposures of sedimentary rocks can be found at the North East of the island where old sandstone quarries may have provided the material for Lindisfarne Priory. Holy Island is another locality on the geologists ‘tick list’ – not to be missed.

*Further information, including where to meet, will be sent to attendees via email nearer the time.

This trip will be run in accordance with government guidance on covid-19.