Kras Frmilske doline v Krajinskem parku Boč-Donačka gora // Karst of Frmile Valley in the Landscape Park Boč-Donačka Gora

V Krajinskem parku Boč-Donačka gora, na vzhodnem robu slovenskega krasa, imamo šolski primer pokrajine v kateri se je zakrasevanje površja »pravkar« pričelo. Ohranjene so oblike iz katerih lahko spoznamo postopni prehod iz rečnega v kraški relief. Frmilska dolina je bila prvotno porečje v nekarbonatnih kamninah, ki pa je zaradi erozije »nasedlo« na karbonatno podlago in se prestavilo v podzemlje. Iz nekdaj enotnega porečja je nastalo 14 aktivnih slepih dolin in 14 zakraselih rečnih dolin brez površinskega vodnega toka. Razčlenjen površinski odtok se nadaljuje v sklenjen podzemni odtok vse do kraških izvirov pri Studeniškem samostanu v dolini Dravinje. Na območju Frmilske doline lahko opazujemo še več rečnih in kraških pojavov: jame, izvire, presihajočo mlako, udorno steno, sufozijske vrtače in požiralnike v nekarbonatnih kamninah, rečne terase in suhe ali fosilne meandre v zakraseli dolini, obvisele doline in spodmole. In the Landscape Park Boč-Donačka Gora (eastern Slovenia), on the eastern edge of the Slovenian karst, we have a textbook example of a territory in which the karstic process has "just" started. There are preserved features, which allow us to understand the transformation from a fluvial landscape to a karstic one. Frmile Valley was originally a river valley in non-carbonate rocks, but due to erosion it became stranded on carbonate rocks. Its waters were mostly transferred to the underground drainage. Fragmentation of the former river valley formed 14 active blind valleys and 14 inactive river valleys that already lost all surface water to the underground drainage. The disconnected surface runoff recharges the same karst aquifer which springs are located at the Studenice Monastery in the Dravinja Valley. In the area of Frmile Valley several fluvial and karstic features can be observed, i.e. caves, springs, a periodic pond, a hill slope collapsed into an underground cave, numerous suffosion dolines and ponors in the non-carbonate rocks, river terraces, dry or fossil meanders in karst valley, hanging valleys, a rock shelter.