Cairnbulg to St Combs Coast
Also within
Condition (NatureScot)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| F1 | Dalradian | Favourable | — | 2009-04-20 |
Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.
Geology & landscape
Geological Period: Cambrian · Rock Type: Gneiss, Granite
Landscape processes: Coastal, Volcanic / Igneous
Description
CAIRNBULG TO ST COMBS COAST The site is a coastal strip, with rock exposures, East of the beach at Fraserburgh, between Cainbulg and Inzie Head, This is an extremely important geological site with regard to the orogenic, mountain forming, evolution of the Dalradian, around 400 million years ago. The structure and stratigraphical significance of these gneisses cannot be over estimated, especially as they have yielded Pre-Cambrian dates similar to those of the Cadomian province. This has prompted speculation that the gneisses may be a far travelled exotic nappe of southern derivation. If this were so, it would require a minor revolution in our interpretation and understanding of Dalradian tectonics. This section extends for 5km through the core of Banff Nappe and the crest of the Buchan antiform, exposing the Inzie Head gneisses which are now thought to be exotic basement emplaced by a thrusting mechanism. The gneisses are variable; consisting of a multi-component host of streaky migmatites with enclaves of semipelitic, calcareous and siliceous meta sediment, with a complex history of intrusion by successive suites of diorite, pegmatite and granite sheets. Ramsay and Sturt’s study (1979) established an extended sequence of nine events of folding, anatexis, intrusion etc. within the gneisses at Cairnbulg beacon. The ribbon gneiss, blastomylonite and phyllonite seen in the gneisses at Portsoy and Dinnet House in Deeside, are not seen in the Inzie Head gneisses. Ramsay and Sturt believe this to be because the gneisses here are located in an internal position. This is within the overall gneiss unit and were largely protected from Grampian (early Caledonian) re-working.