Neotectonic activity

Like the whole of the Classical Karst of Slovenia, the area investigated lies on the Adriatic sub-plate, a part of the African macroplate. The contact with the European continent lies about 80km to the north. During the last 2 Ma, changes in the motion of the Adriatic sub - plate have led to the establishment of several dextral strike - slip faults of Dinaric trend (i.e. southeast to northwest direction). As a reflection of its 12 km displacement and ongoing neotectonic activity, the Idria Fault is usually considered the... 

Presence of unpaired terrace was also indicative of neotectonic activity. The traces of N-S lineaments in colluvial deposits along the valley slope marked by Unear topographic elements of varying... 

A shear zone with more than 30 m thick shear gouge trending 120° 300° was also recorded at the road section on the left bank at distance of about 1.5 km downstream of the proposed powerhouse site. About 2 km downstream of the proposed powerhouse, huge sheared rockmass with gouge appeared to be overridden in the debris/colluvium (Fig. 5) which has been suspected to be a signature of neotectonic activity. 

Figure 5. Neotectonic activity along road cutting, proposed powerhouse site.

The shear zones encountered in and around the powerhouse site (UGPH-1) are likely to be encountered at the powerhouse cavern and other appurtenant structures, thereby giving rise to stability problem. It was also not feasible to shift the powerhouse further downstream as frequency of shear zones increases and imprints of probable neotectonic activity, was anticipated. Two alternative arrangements (UGPH-2 and SPH-1) for housing powerhouse structure were then suggested for consideration. 

In massifs of karstic rocks there is an effect of local dynamic changes of the hydrogeological parameters, spatially connected with zones and sites of the increased density of fissures, breakage, faults zones. The effect intensifies within the areas of neotectonic activity. Here specific water inflows reach maxima, the mineralization of underground waters sharply raises. Changes have a wide range of the periods, including intra-day. 

Luirei K, Bhakuni SS (2008) Geomorphic imprints of neotectonic activity along the frontal part of eastern Himalaya, Pasighat, East Siang district, Arunachal Pradesh. J Geol Soc India 71 502-512 Maskrey A (1989) Disaster mitigation a community based approach. 

Fenton C (1992) Late quaternary fault activity in nmth west Scotland. In Momer N-A, Owen LA, Stewart I, Vita-Finzi C (eds) Neotectonics - recent advances. Quaternary Research Association, London, pp 62... 

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