The Use of Structural Geological Terms and their Importance for Karst Caves

Abstract

Strukturno geološke raziskave na kraških terenih zajemajo enake strukturno geološke izraze kot na drugih geoloških terenih. Ker pa imamo na krasu opravka s posebnimi geomorfološkimi izrazi, se nekateri strukturno geološki elementi, ki so na poseben način povezani z določenimi kraškimi oblikami, uporabljajo kot posebni termini, ki so različni od terminov v uporabi na nekraških terenih. Na slovenskem krasu lahko ločimo dva najpomembnejša strukturna elementa, ki sta pomembna za razvoj jamskih rovov, in sicer lezike in tektonske strukture. Med lezikami so za razvoj inicialnih rovov posebno ugodne tektonsko deformirane lezike. V najdaljših slovenskih jamah, kot so Postojnska, Predjama in Škocjanske jame so za razvoj rovov v inicialnih, kot tudi v starejših in mlajših obdobjih zelo ugodni medplastni zmiki, deformacije narivanja in gubanja ter tektonsko pretrte cone (razpoklinske, porušene in zdrobljene).

Structural geological studies on karst areas operate with the same structural geological terms as on other geological regions. But because of special geomorphologic terms characterized for karst areas, some structural geological elements, which are in a special way connected with particular karst forms, are used as a special terms, different from those used on non-karstic areas. For Slovene karst we need to divide two most important structural elements that are important for development of cave passages, bedding planes and tectonic structures. And between bedding planes the ones that are tectonically disrupted are very favorable for development of initial cave passages. In the longest Slovene karst caves as Postojnska jama caves, Predjama and Škocjanske jame caves interbedded movements, thrusting and folding deformations, and tectonically broken zones (fissured, broken and crushed zones) are very favorable for initial, and also for older and younger stages of passage development.