Journal of Cave and Karst Studies - ISSN 1090-6924
Volume 63 Number 1: 41-47 - April 2001

A publication of the National Speleological Society

Caverna Dos Ecos (Central Brazil): Genesis and geomorphologic context of a cave developed in schist, quartzite, and marble
Ivo Karmann, Luis Enrique Sánchez and Thomas Rich Fairchild

Abstract

Caverna dos Ecos (Echoes Cave) occurs in low-grade metamorphic rocks of the Mesoproterozoic Canastra Group, 60 km west of Brasília, and exhibits a total linear development of 1600 m and a depth of 140 m, with halls up to 100 m across and 35 m high, a gallery 350 m long and 70 m wide, and at its lowest point, a lake 280 m long and 10 m deep. What makes this cave so unusual is that ~70% of its large volume is presently developed within schist and quartzite. Detailed structural study, together with speleomorphologic analysis, revealed two phases of speleogenesis: the first, typical of carbonate rocks, created phreatic tubes along the intersections of fractures and bedding planes, whereas the second involved breakdown processes that opened up large vadose cavities in the overlying schist and quartzite but without producing any indication of karstic relief in the overlying topography.

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