Skatie Shore Fieldtrip, 30th Aug 2026
A wee bit of advertising for this Aberdeen Geological Society trip that I am co-leading to Skatie shore just to the North of Stonehaven.
https://www.aberdeengeolsoc.org.uk/field-trips/
The dashed line that runs from SW-NE just south of the shore is the Highland Boundary Fault. This fault is the boundary between the Grampian Highlands (metamorphic rocks belonging to the Cambrian and Pre-Cambrian) and the Old Red Sandstone sedimentary rocks (Devonian period mainly) to the South.
Just to the S, Craigeven Bay (opposite) is probably the most southerly occurrence of the Dalradian on Scotland’s East Coast. Here, there are some nice examples of different stages of folding in what is an area of quite low grade metamorphism. Folding and metamorphism occurred during the Grampian Orogeny (around 460 Ma), one of the earlier phases of the lengthy Caledonian Mountain Building period.
Complete fold (hinges) are more difficult to spot at least at the start of the Skatie section. In fact, grading bedding and the relationship between the dip of bedding and of structural foliation (related to folding) has been used (many moons ago) to work out way up and reconstruct the various folded structures found here.
Folding started during formation of the Tay Nappe (stage D1) and folds have been reworked through to the D4 stage at the time of the formation of the Highland Border Downbend. An example of one of these folds is shown opposite - its quite a tight fold (i.e., hinge area) which we may call an isoclinal fold and it plunges towards the shore (away from the sea in the photo). When a fold plunges, the hinge line is not horizontal, it is inclined.
This area is also well known for a change in index minerals from S to N. There is no garnet in the meta sediments and metamorphic rocks in Craigeven Bay as we are in an area of quite low metamorphic grade (T/P). You’ll notice garnet being recorded at the top of the map (above) telling us that we are entering an area of higher metamorphic grade. There is also staurolite in this area indicative of slightly higher grade than garnet but found frequently with garnet. During the trip we will walk across these various zones of mineral assemblages.
Plunging anticline N of Perthumie Bay which has probably formed during the formation of the highland border downbend