Residual peaks and areal scouring

Two views from the little Norwegian archipelago of Traena, where these isolated residual peaks can be seen from a great distance away, across the gently undulating surface of the strandflat.

I have been intrigued to see the use of the word "Rauk" used in various contexts -- meaning the steep residual peaks that are left isolated on the Norwegian strandflat or on other extensive areas of areal scouring.  I'm unhappy about the use of this word because in Swedish and Norwegian it is also used for small sea stacks along the coastline.  Clearly these are vastly different in terms of scale, process and surface characteristics -- although, that having been said, there are in some cases old sea caves at the break of slope at the base of the steep rock faces.

In Norway, according to Hans Holtedahl, the word "nyker" is used for these large features which dominate their local landscapes -- but that's a difficult word to translate since "ny" means "new" and "ker" can be used for skerries or low undulating shoals and islets close to sea level -- as in "skärgård" in Swedish..........

Another classic landscape dominated by residual peaks and ridges is that of the Lofoten Islands, to the north of Traena:

There are similarities, but the mountains and ridges are much larger and more spectacular in the Lofotens, and the landscape is best interpreted not as a landscape of areal scouring but as a landscape of intense glacial activity which has been partly flooded by the postglacial rise of sea level.  Look at all those cirque basins, all the way down to sea level.  Shades of the Faroe Islands.  There are traces of the strandflat here, but they are not very extensive.  If we look at the Lofoten landscape as a whole, there are more similarities with the fjord landscape of western Norway than with the outer skerries and strandflat.

As we can see from the above satellite image, the Lofoten Archipelago is really a part of the Norwegian mainland, where the mountains just happen to reach the sea.  In the main islands we are looking at the northern side of a major glacier outlet trough called Ofotfjorden -- clearly visible in the image.  There are other (rather complex) outlet troughs to the north.  The straits between the islands are very narrow, created by ice scouring along bedrock fractures.  The spectacular ridges and isolated peaks are all of glacial origin.

 

Here is another set of rather spectacular peaks -- the Seven Sisters in Hordaland, again very close to the Norwegian coast.  These are thought to have a geological / structural origin, since they are made of hard rocks flanked by strips of softer rocks which have been heavily eroded by ice streaming out towards the coast.  If we want, we can call the summits residuals.........

Fildes Strait, King George Island, South Shetlands, Antarctica.  A skerries landscape (strandflat?) with prominent residuals (probably volcanic plugs) along the present shoreline.

North Spit, South Shetland Islands.  A raised marine platform (strandflat?) with a prominent isolated residual on the right.

And the point of all this?  Well, residuals or isolated peaks with very steep flanks can be formed in a number of different ways.  Like the "monadnocks" on St Davids Peninsula in Pembrokeshire, which almost always coincide withy Ordovician igneous rock outcrops, they may at one stage have been islands in a shallow sea, but glacial, periglacial and even desert processes may at some stages have played a part in their formation.

Carnllidi, near St David's -- seen from Ramsey Island

Coastal platform and residuals (normally referred to as "monadnocks") at the western end of St David's Peninsula. (Photo: Deborah Tilley)