Uvala (landform)

Uvala is originally a local toponym used by people in some regions in Slovenia, Croatia, Bosnia and Herzegovina, Montenegro and Serbia.

In geosciences it denotes a closed karst depression, a terrain form usually of elongated or compound structure and of larger size than that of sinkholes.

However, recent empirical research (~2009) revised poor mainstream definitions, stating that "…uvalas are large (in km scale) karst closed depressions of irregular or elongated plan form resulting from accelerated corrosion along major tectonically broken zones.

"[1] This is arguing for the "re-introducing of uvalas into modern karstology" – distinguishing them from dolines and poljes in size (typically) and "also in morphology and combination of genetic factors", which give them "a status of a particular karst relief form.

As the father of Karst Morphology and Hydrogeology, Cvijić envisioned the phenomena of karstology in his publications, first in regions of Europe and then all over the world.

[5] With his influence and publications the internationally renown German morphologist, Herbert Lehmann,[6] put an end to the focus of karstology on warm temperate climate.

Possibly the studies of geological dating, interdisciplinary Tectonics, Seismotectonics and Climatology will open a window to look into earlier periods of evolution.

The recent progress in methods and measuring techniques in the sciences[12] with the regard to geological objects allows 'dating' in dimensions of several hundred thousand or even million years – with high precision.

[13][14] Some progress in dating was made by ensuring that examined sediment probes and fossils have not only been exposed to surface, where denudation, weathering or corrosion are in effect.

In 2006 fossil remains in sediments of unroofed caves of the Middle Swabian Alb were successfully dated, Ufrecht (2006).

The remains of large land-mammals of seven genera were lithologically and bio-stratigraphically (paleontologically) classified into the biozones MN1 to MN17 of the European Land Mammal Mega Zones (ELMMZ) table.

In the Postojna Caves (Slovenia) the method of paleomagnetism in combination with paleontological studies yielded a dating comparable to that on the Swabian Alb.

[16][full citation needed] Carbonate rocks of the Dinarides are 4500 to 8000 m thick and thus reach deep below the current sea level.

[20] The geographer Jelena Ćalić,[21] chose to analyze large karst depressions using geomorphological (morphometrical) and structural geologic mapping methods.

[23] The Croatian mountain chain Velebit is probably the richest area in karstic uvalas of the Dinarides, Poljak (1951) cited by Ćalić (2009) p. 70.

The deep incision of Velebit's most prominent uvala Lomska Duliba can be explained by the presence of the Jelar breccias, Ćalić (2009), p. 72.

[...] "At this stage of research, it can be concluded that uvalas are large (in km scale) karst closed depressions of irregular or elongated plan form resulting from accelerated corrosion along major tectonically broken zones.

Their bottoms are undulating or pitted with dolines, seldom flattened by colluvial sediments and always situated above the karst water table."

[...] "The depressions of this kind are not present on karst levelled surfaces, but only in areas with more or less dissected relief;" [...] they "are forms of accelerated corrosion – not as points as dolines, but 'linear' or 'areal' [...].

Yet, they consider the term uvala indispensable and use it no less than six times to describe karst phenomena found in different epochs, climates and regions of various continents, in some cases with reference to other authors.

Pfeiffer (2010) discusses Karstwannen ("Karst depression","Uvala"," Polje") of the Swabian Alb, the Franconian Jura and those of the Causses (southern France).

A lot of geological research in speleology, tectonics and petrology has been done, but this rarely focuses on large closed karst depressions like uvalas.

Šušteršič, F., Acta Carsologica 14–15, Ljubljana 1986 Fuchs et al. (1987), Beiträge zur Karstmorphologie, Herbert Lehmann, Reprint noch aktueller Beiträge, Fuchs, F., Gerstenhauer, A., Pfeffer, K.-H., (ed), Stuttgart 1987 Jennings (1987) Karst Geomorphology, Jennings, J. N., Oxford 1987 White (1988), Geomorphology and hydrology of Karst terrains, White, W.B., Oxford, 1988 Bayer & Groschopf (1989), Karstwannen der Schwäbischen Alb, Bayer, H.-J.& Groschopf, P., Blätter des Schwäbischen Albvereins, 6 1989, Stuttgart Cocean & Petrescu (1989), Types morphogénétic d'ouvala dans le karst de Mont s Apuseni.

(Iran) Kuhta & Baksic (2001), Karstification dynamics and development of the deep caves on the North Velebit Mt.

Kuhta, M., Baksic, D., 13. International Congress of speleology, Brasil 2001 Sauro (2001), Aspects of contact karst in the Venetian fore-alps.

Sauro, U., Acta Carsologica 32/2, Ljubljana 2003 Nicod (2003), A little contribution to the karst terminology: Special or aberrant cases of poljes?, Nicod, Jean, Acta Carsologica, 32,2 Ljubljana 2003 Abel (2003), Untersuchungen zur Genese des Malmkarsts der Mittleren Schwäbischen Alb im Quartär und jüngeren Tertiär, Abel, Thekla, Tübingen 2003 Ufrecht/Abel (2003): Zur plio-pleistozänen Entwicklung der Bären- und Karlshöhle bei Erpfingen (Schwäbische Alb) unter Berücksichtigung der Sinterchronologie, Ufrecht, W., Abel, Th.

Gams, I., Acta Carsologica 34/1, Ljubljana 2005 Jalov &Stamenova (2005), Historical data for karst phenomena in the province of Macedonia, Greece, Jalov, A., Stamenova, M., Greek Cavers Meeting, Karditza 2005 Ufrecht (2006): Ein plombiertes Höhlenruinenstadium auf der Kuppenalb zwischen Fehla und Lauchert (Zollernalbkries, Schwäbische Alb), Ufrecht, W., Laichinger Höhlenfreund, Laichingen 2006 Abel (2006): Zur Verkarstungsgeschichte der Bären und Karlshöhle bei Erpfingen, (Schwäbische Alb), im Plio-Pleistozän unter Berücksichtigung von Sinterchronologie und Paläontologie, Abel, Th.

Zupan Hajna et al. (2008), Zupan Hajna, N., Pruner, P., Mihevc, A., Schnabel, P & Bosák, P; Cave sediments from the Postojnska-Planinska caves system (Slovenia): Evidence of multi-phase evolution in epiphreatic zone, Acta Carsologica, 37/1, Ljubljan 2008 Calaforra Chordi & Berrocal Pérez (2008), El Karst de Andalucía, Calaforra Chordi, J.M., Berrocal Pérez, J.A., Sevilla 2008 Bakšić (2008), Cross section through Mt.

2012 Vlahović et al. (2012), Marine to continental depositional systems of Outer Dinarides forland in intra-montane basins, Fieldtrip Guide.