Page 260 - Changing Living Spaces

Aleksander Panjek and Gregor Kovačič

The erosional relief forms on the slopes of the northern edge of the
Karst, i.e. also in the vicinity of Štanjel, were formed in a younger geological
period, probably in the last 2 million years, when the surface of the neigh-
bouring flysch area north of the Karst lowered significantly (Radinja 1974,
21–33). This lowering is the result of the lower resistance of flysch rocks
to denudation processes, which means that the surface on flysch rocks
lowers much faster than the surface on carbonate rocks (limestones and
dolomites). Various measurements have shown that under current cli-
matic conditions, the surface on the Karst plateau lowers at a rate of 20-
100 mm per 1000 years (Cucchi, Forti and Ulcigrai 1994, 55–62; Gams
2003), while the denudation rate on flysch rock is 400-5000 mm per 1000
years (Zorn 2008).
The above-mentioned difference in the resistance of the rocks to fac-
tors related to surface lowering has caused the valleys in the northern
flysch area of the Karst to deepen and move to a lower position compared
to the plateau. This caused the surface waters of the northern part of the
Karst to change their course toward the lower flysch area; the fluvial ero-
sion caused by the streams began to form erosion gullies on the northern
slope of the Karst plateau. As long as the area was covered with flysch,
smaller intermittent surface waters flowed from this edge towards the
Branica, Raša and Vipava valleys. After the flysch was eroded in the upper
part of the Trsteljska brda hills and on the northern slopes below, a series
of erosional gullies emerged as inherited fluvial-denudational landforms
on carbonate bedrock; in the case of the Vrpoljska brda hills in the south
of the Karst, Uroš Stepišnik (2011) came to the same conclusion. The in-
herited landforms on the northern marginal slope of the Karst prove that
there was a major flysch thrust sheet in this area, which was eroded (den-
udated) in the course of geological history.

‘Neverlake’ Near Štanjel: Physical-Geographical Aspects
The main subject of interest is the area in the immediate vicinity of Štanjel
called ‘Jezero’ (‘Lake’). It is a doline of a distinctly elongated shape, run-
ning in a northwest-southeast direction, located about 1 km northwest of
Štanjel. The longer axis of the doline measures 1,160 m, while the short-
er axis of the widest part of the doline measures only 161 m. Thus, the
doline’s shape resembles a valley, but it does not meet the geographical
criteria for this relief shape, since it is a depression closed on all sides.
The circumference of the doline at the edge of the relatively flat bottom
with the surrounding hillslopes is about 2,600 m; its area is just under

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