Geological Characteristics of Desert and Upper Desert Caves (NE Blue Diamond Hill, Nevada, USA)

Abstract

Desert Cave (72 m) in Upper Desert Cave (62 m) sta najdaljši znani jami na Blue Diamond Hill in se nahajata znotraj enega od več kanjonov. Jami sta razviti v apnencu iz zgornjega dela spodnjega permija (Kaibab formacija). V najnižjem delu Desert Cave, ki je 12,6 m globoka, jamski rov doseže litološko mejo med Kaibab apnencem in sedimentacijsko brečo (spodnji del Kaibab formacije). Stik breča-apnenec je ena od inicialnih struktur iz freatičnega obdobja razvoja jame, vendar ne pred mezozojskimi narivnimi deformacijami. Površinska razdalja med vhodoma v Desert in Upper Desert Cave je 81 m, jami nista povezani. Desert Cave se nahaja 2 km zahodno od nariva Bird Spring. Prevladujoče smeri razpok v jami so NW-SE in NE-SW. Smer rova je skoraj vzporedna s smerjo razpok NE-SW. Obstaja jasna povezava med javljanjem podorov v jami in moćneje izraženimi razpokami v smeri NW-SE.

Desert Cave (72 m) and Upper Desert Cave (62 m) are the longest known caves in Blue Diamond Hill and are situated in one of its canyons. Caves are developed in limestone of latest early Permian age (Kaibab formation). In lowest part of Desert Cave, which is 12,6 m deep, cave passage reaches lithological contact between Kaibab limestone and sedimentary breccia (lower part of Kaibab formation). The contact breccia-limestone is one of initial structures in phreatic period of cave development but not before Mesozoic thrusting tectonics. Surface distance between entrances to Desert and Upper Desert Cave is 81 m, the caves are not connected. Desert Cave is situated 2 km W from Bird Spring thrust. Prevailing fissure directions in the cave are NW-SE and NE-SW. Passage direction is almost parallel with the NE-SW fissures direction. There is obvious connection in occurrence of breakdown in the cave with strongly expressed fissures in NW-SE direction.