Naslov
The origin and morphology of submarine spring Vrulja Zečica (Croatia)

Autori
Kovač Konrad, Petra ; Jalžić, Vedran ; Buzjak, Nenad

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts / Mihevc, Andrej ; Gabrovšek, Franci - Postojna : Znanstvenoraziskovalni center SAZU, Inštitut za raziskovanje krasa ZRC SAZU = Karst Research Institute at ZRC SAZU, 2012, 58-58

Skup
20th International Karstological School "Classical Karst" : Karst Forms and Processes

Mjesto i datum
Postojna, Slovenija, 18.06.2012. - 23.06.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
speleogenesis; speleomorphology; submarine spring

Sažetak
The occurrence and characteristics of submarine springs along Adriatic coast in Croatia are determined by the geological and hydrogeological conditions of the littoral and its higher hinterland, geotectonic relations, karst porosity and climate. Due to favorable conditions, Velebit Channel located between Velebit Mt. and large islands of Krk, Rab and Pag is very rich in different types of submarine springs (vruljas) and coastal springs. They are outlets of well developed karst aquifers fed by high precipitation in the mountain area and water from sinking zones, mostly in Lika region. The submarine spring Vrulja Zečica is located in the SE part of Velebit Channel 7.8 km SE from Starigrad. Although it was known to the divers and researchers for decades ago, from 2011 it is an object of intensive speleological and geomorphological researches. It is a branched cave with vertical (shaft) entrance. The entrance is located on an inclined sandy sea bottom at a depth of 6-9 m. It is followed by the vertical passage of spiral-shaped plan. The start of horizontal passage is at the depth of 37.5 m. The lowest passage bottom point is at the depth of 43 m. After series of cave diving explorations total length of known passages is 650 m and 197 m was surveyed. In surveyed part it is up to 17 m wide, and up to 5 m high. The cave is located in the area build of intensively karstified Cretaceous and Tertiary carbonate beds (limestone and breccia). The passages were formed along fissure systems of E-W, NE-SW and NNE-SSW direction. All observed horizontal passage parts have typical phreatic cross section. But the abundant speleothem accumulation indicates changes in hydrological regime of the cave in geological past. Termination of speleothem deposition is the result of groundwater level rising and the gradual penetration of sea water due to Late Plesitocene/Holocene transgression. Based on the size of stalagmites (>1.5 m long) and columns (2.5 m in height and 1 m in diameter), it can be concluded that vadose phase lasted relatively long. Apart from speleothems in their primary position of growth, along the horizontal passage numerous broken speleothems can be found. It is a result of strong mechanical action of flowing water throughout the hydrologic activity of the spring. It is periodically active only during the wet season, as a result of abundant precipitation or snow melting in higher mountain hinterland.

Izvorni jezik
Engleski

Znanstvena područja
Geografija

POVEZANOST RADA