WGCG Spring 2021 Newsletter - Flipbook - Page 5
Spring 2021 Newsletter
Arran Field Trip September 2020
Deborah Parke, Paul Abernethy, Peter Hawksworth
Following the talk given at an online meeting of the WGCG by Stuart Blake of the Lochranza Field Studies
Centre on Arran, Paul and I were interested to note that there were opportunities available to visit Arran
and see its geology for ourselves. Little did we know that, over in Ettington (the next village along the Fosse
Way from ours), Peter was planning the very same trip. On arrival at the Field Centre, we were given a tour
of the facilities and shown to our rooms, where there was time to freshen up before meeting the other
members of the group for dinner. This is where we three, and the other four members of our group, met.
The field activities during the week took us to all parts of the island, with the exception of the central igneous
complex. It was a very full week, so only some highlights of the visit are mentioned here. In order to
experience the geology of Arran fully, it is really necessary to visit the island - and the Lochranza Field Centre
is the ideal base from which to explore.
On day 1 we met outside the classroom for an introductory talk by Stuart on the geological features and rock
types we would be seeing during the week. Stuart explained that the Isle of Arran sits astride the Highland
Boundary Fault, so it is possible to see both the ‘highland’ and the ‘lowland’ geology of Scotland in this one
small area. We were also introduced to Hannah, one of the geologists working at the Centre, who assisted
during the trip. Ffion, another geologist, joined us later in the week.
The introductory talk was followed by a full day at Fairy Dell, in the north of Arran (only a short walk from
the Centre), looking at Carboniferous rocks and Permian sandstones, interspersed with dykes. On the way
back to the Field Centre, we stopped at Hutton’s unconformity. This caused a certain amount of confusion
because, whilst some of us were familiar with Hutton’s unconformity at Siccar Point near Edinburgh, most
were unaware of Hutton’s unconformity on Arran. Whilst there, Stuart demonstrated the use of the compass
clinometer to determine directions and angles of dip. The unconformity displays Carboniferous sandstone
dipping to the North at 30º, whilst the Dalradian slates and phyllites dip to the South (inland) at 45º.
Hutton’s unconformity on Arran
Photo credit: Paul Abernethy