In the period from September 25th to October 6th, 2023, a Project collaborator of Component 2 of the CRONOS project (Tvrtko Korbar, PhD) carried out the geological analysis of the borehole cores from locations of borehole accelerographic systems in Imotski, Sinj and Vrlika.
The core of the borehole in Imotski in the uppermost layer contained eluvial, recent soil in the form of compacted silt. After that, mostly loose gravels and sands appear, along with some segments of silt. A gray to yellowish-brown poorly consolidated silt continues, with an interlayer of gravel mixed with sand and silt. All the way to the bottom of the borehole (40 m) there is light grey poorly consolidated silt, with an increased proportion of clay towards the bottom of the borehole. Resedimented carbonate material, probably originating from flysch, is present throughout the core. The layers are horizontal.
The core of the borehole in Sinj in the uppermost layer contains predominantly loose silt. Next, siltous clay appears, brown in the upper part, and light grey to dark grey, even black bituminous in the deeper layers. Within this interval there is an interlayer of peat and a thicker layer of limestone with shells. Further on, a weakly cemented limestone appears, and at the very bottom of the borehole (25 m), a grey siltous compacted clay is present. All analysed materials are probably of Quaternary origin, with limestones possibly belonging to the peak Neogene. The layers are horizontal.
The uppermost layer of the core from Vrlika consists of eluvial, recent soil in the form of compacted brown soil, with mostly small carbonate gravel (potentially anthropogenic). Next, deposits of reddish to yellowish-brown compacted siltous clay continue, representing surface Quaternary deposits. Down to the bottom of the borehole (17 m), grey deformed white gypsum is present, with fragments and/or fillings of siltous clays. These deposits represent the bedrock of Perm-Triassic origin.
Prepared by Bruno Mravlja
