Structural history of the Idrija mercury deposit


  • Ladislav Placer


Three phases can be distinguished in the development of the geologic structure and structural history of the Idrija mercury deposit. At the Middle Triassic period there was a structure favourable for the control of ore-forming fluids along Triassic faults bounding the Idrija fault trough. A phase of stronger tectonic movements followed in the early Tertiary period. At that time an extensive rock sheet has been thrust forward from northeast to southwest obliquely over the Idrija fault trough. The ore deposit has been broken and displaced along fold-faults. Three overthrust units have been driven one over another in this way. The overlying unit of inner thrust sheet of Tičnica has, apparently, been brought forward and its mineralized portion was denuded. The middle unit, designated as the Idrija inner thrust sheet, represents the present day Idrija ore deposit. The underlying unit is supposed to be covered by the Trnovo nappe somewhere northeast of Idrija. It was within neotectonics time that the middle unit was divided into three fault blocks. Two of them are the ore deposits of Idrija and Ljubevč, and the third has been removed.


How to Cite

Placer, L. (1982). Structural history of the Idrija mercury deposit. Geologija, 25(1), 7–94. Retrieved from