Geologically speaking, the area can be classified as a particularly well-developed classic fjord landscape.
The area is a relatively young and geologically active glacial landscape, and geomorphologically speaking it is unique. The fjords themselves as well as many of the valleys along the fjord are typical examples of glacially shaped “U” valleys, between which you also find the classical “hanging valleys”.
Large parts of the area’s bedrock belong to Jotundekket (a large nappe stretching for several kilometres). Large sheets of Precambrian rock were folded and metamorphosed into gneiss, gabbro, mangerite and anorthosite during the Caledonian Orogeny. These are all hard types of rock that offer little nutrition that settled on top of younger, phyllite rocks.
Anorthosite is a metamorphosed igneous rock developed from the mineral feldspar. This rock is very light in colour, which are distinguished by their light grey tones that are easily noticeable on the bare mountains. This is especially true for the area between the mountain of Bleia and Storebotn, which is dominated by these anorthositic rocks. Another eye catching area is “Kvitmålane” in the mountainside of Skomakarnipa at the entrance to the Nærøyfjord and further in towards Dyrdal. The area’s white, steep mountainside lights up for all those that travel outwards from Aurland. Anorthosite has qualities that are of commercial interest, the most important areas in this regard are found in a larger area at the mountain of Jordalsnuten and particularly to the east of the valley of Nærøydalen.
The fjord landscape is especially magnificent near the mountain of Bleia. The north face of the mountain has the highest total relief of the Sognefjord, the range going from the 1000m deep fjord to the top of the mountain at 1717m.a.s.l. On the north face of the mountain ravines and ridges create unusually great, distinctive shapes. The quaternary processes have been especially active in this area. The highest part of Bleia and the mountain area to the south are remnants of the old plains, which are representatives of the landforms prior to the ice ages.
The steep mountainsides make it possible for us to study the quaternary phenomena such as paths of reoccurring land and rock slides and avalanches, talus cones and annual avalanches. Inste and Yste (inner and outer) Drøfti on the north face of Bleia are the most noticeable avalanche and other mass paths in this area. Two good examples of such paths in the Nærøyfjord are Breidskrea near Bakka and a large marked path above Styvi. There are obvious traces of a large rockslide having occured in the Bleia area, just above Revsnes.
In the innermost parts of the valley glacial cirques can be found. In these areas you can often find small bodies of water that have been created by glaciers in these cirques having forced their way down into the bedrock. Particularly good examples of these processes are the lakes of Huldabotnen in the inner part of the valley of Styvisdalen and Undredalsvotni to the east of Skammadalshøgdi.
There are a number of large and small glaciers as well as eternal snowdrifts within the Nærøyfjord World Heritage Park area. The biggest glacier is the Fresvikbreen (m.a.s.l.) on the western side of the Nærøyfjord. To the east you find the smaller glacier of Syrdalsbreen (1761m.a.s.l.). You also find a smaller glacier to the east of the mountaintop of Bleia (1717m.a.s.l.). There are a number of minor glaciers and eternal snowdrifts in the vicinity of Fresvikbreen and in the mountain area between the Aurlandsfjord and the Nærøyfjord. Breidskrea near Bakka is a powerful example of the active geological processes in the Nærøyfjord area.
The majestic waterfalls of Sivlefossen and Stalheimsfossen in the inner parts of the valley of Nærøydalen are famous tourist attractions. Less known is the waterfall in Vetlahelvete (literally Little Hell) in the canyon dropping down from the valley of Jordalen. All these waterfalls are examples of rivers that used to flow in a south-westerly direction towards Voss. There are a total of 25 waterfalls throwing themselves down the mountainsides in the Nærøyfjord area. The waterfall called Kjelfossen has a free fall of 150 metres (492.1ft) and a total fall of 840 metres (2755.9ft), making it the 18th highest total waterfall drop in the world. Geologically speaking, since the glacial ice melted the landscape has mainly been shaped by the free-flowing water in rivers and streams. The fact that there are entire watercourses that have experienced no outside intervention, where erosion and other land forming processes have been allowed to take place naturally, remains a very distinctive part of the area. In this area the watercourses of Undredalselvi, Dyrdalselvi, Kolarselvi (in the valley of Nordheimsdalen), Nærøydalselvi (with the exception of the tributary Jordalselvi), Nisedalselvi, Vossovassdraget and Flåmselvi are all protected from any hydro power development.