Geological Controls in the Development of Caves in the South-Central Ozarks of Missouri, USA

Povzetek

Področje Ozarkov v Missouriju je eden največjih kraških terenov v ZDA. Prevladujočo litologijo predstavljajo kambrijski in ordovicijski dolomiti in peščenjaki. Številne, večinoma horizontalne jame in veliki kraški izviri so značilnosti krasa Ozarkov. Od oktobra 1996 do vključno maja 1999 smo obiskali 23 kraških jam, za 18 jam v osrednjem delu južnih Ozarkov smo naredili geološke karte. Za ta članek smo predstavili geologijo štirih jam. Prevladujoča geološka zakonitost, ki vpliva na oblikovanje jam je vpad plasti in preferenčna plast stromatolitnega dolomita. Edina možna povezava med geološko strukturo in smerjo jamskih rovov je smer rovov sever-jug in smer razpok sever-jug.

The Ozark Plateaus Province of Missouri is one of the largest karst areas in the USA. The dominant lithology is Cambrian and Ordovician dolomite and sandstone. Numerous, mostly horizontal caves and large springs are characteristic of Ozark karst. From October 1996 through May 1999, 23 caves were visited and geologic maps were made for 18 caves in the Ozarks of south-central Missouri. For this paper, the geology of four of the caves is discussed. The prevailing geologic control on cave development is bedding plane dip and preferred strata-a stromatolitic dolomite bed. The only recognized relationship between geologic structure and cave passage trends is the correlation of a N-S trend of cave passages to a general N-S trend in joints.