GEOL. CROAT . 50/2 299 ZAGREB 1997 

Hydrologic Evolution of a Carbonate Aquifer (Dinaric Karst, Croatia) 

Lj ubomir BABIC' . Damir LACKOVIC' and Nada HORVA TINCIC' 

Dinaric Karst terrains contain specific, lam inated 
speleothems, which line all surfaces of subterranean 
voids including Cretaceous bedrock limestone, and old­
er vadose speleothems and clastic sed iments. These 
speleothems may attain a thickness of one metre. Depo­
si tion of these spe leothems took place during a 10ng­
term phreatic period in the Late Quaternary. This is in 
cont rast to well-known, widespread speleothems, which 
were, and are deposited in vadose and uppermost phre­
atic settings. Furthermore, the origin of these phreatic 
speleothems departs from common experience by the 
domi nan t di ssoluti onal w ideriing of underground con-

I Depa rtment of Geo logy and Palaeontology, Faculty of Sc ience, 
Uni versity of Zagrcb. UI. kralja Zvo nimira 8, HR- IOOOO Zag reb , 
Croatia. 

2 Rud er Boskovic Instit llte, Bijcni cka ccs ta 54, HR- I 0000 Zagreb, 
Croati a. 

duilS when saturated. Phreatic speleothems can be imp­
ortant strat igraphic marker for the stratigraphy of cave 
sediments. This approach revealed a sequence of three 
hydrologic stages: ( I) pre-phreatic stage wi th dominant 
vadose condi tions and dissolution processes, (2) phreat­
ic stage when the ground-water level was very high in 
the large karst area, and when the volume of the voids 
decreased, and (3) the last , dominantly vadose stage 
during which voids were enlarged for the second time, 
and phreatic speleothems may be covered by younger 
clastics and vadose speleothems. 

This abstract was presented at the scientific meeting 
dedicated to the 80th anniversary of the life of 

Professor Milan Herak, 
held on March 5th, 1997 in Zagreb 



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