Larger Umbira Cave

Michael Laumanns - 24/11/2015

Umbira village, Mbira zone, Cheringoma district, Sofala province. 35°00'52"E: 18°20'35" N (GPS WGS84), ca. 180 m asl. Surveyed on 22 Aug. 1998 by Artur Fernandes and Michael Laumanns (BCRA-Grade 4b). Length: 106 m. Vertical range: -8 m. The cave is identical with „Caverna Cheringoma no.3 - zona Aldeia Comunal 1° de Maio, Inhaminga“ (Vachamuteco 1982). Three roof collapses of 6, 3 and 4 m depth (steel rope ladder) give access to dry (fossil) horizontal cave passages predicted by E-W and SSW-NNE clefts. The latter ones were enlarged by solution of the limestone and belong probably to an older generation of clefts while the E-W clefts remained small and narrow. The cave does not contain speleothemes like stalagmites and stalactites. Larger Umbira Cave contain guano deposits which were exploited during colonial times. Today only a small bat colony roosts in the cave, consisting of at least two species of small and large rhinolophides. The guano resources were estimated by Vachamuteco (1982) with 3,5 m thick, 40 m long and 7 m wide (280 square metres). He reported about 2.000 bats. The southern continuation of the cave, small and blocked with rocks, has a hydrological connection with a shallow 5 m deep dry valley draining the water of the wet season which has some more small resurgences active during rainy weather only.