Produção Nacional
Origin and Evolution of Toca da Boa Vista and Toca da Barriguda Cave System in North-eastern Brazil
2017; Springer International Publishing; Linguagem: Inglês
10.1007/978-3-319-53348-3_56
ISSN2364-4591
AutoresAugusto S. Auler, Alexander Klimchouk, Francisco H.R. Bezerra, Caroline Léssio Cazarin, Renata Ennes-Silva, Fabrizio Balsamo,
Tópico(s)Geology and Paleoclimatology Research
ResumoToca da Boa Vista and Toca da Barriguda (TBV-TBR) are two of the longest caves in South America and, although not physically connected, share a common origin and evolution. Together, they comprise over 145 km of passages that are mostly developed in five lithological units in a Precambrian dolomite host rock. The now relict caves display a mixed ramiform/spongework/network pattern that shows clear hypogene morphology. The inception of speleogenesis cannot be precisely determined but likely occurred several tens (if not hundreds) of millions of years ago, placing this system among the oldest caves in the world. The TBV-TBR system is controlled by a NE–SW-oriented fracture corridor; passages follow anticlines and troughs, showing morphological variations depending on the vertical position in relation to the carbonate units. The cave system is represented by a laterally extensive maze controlled by a highly fractured unit in which ascending flow was restricted by an upper less fractured unit (hydraulic seal). The long evolutionary history of the cave left numerous imprints, including widespread and remarkable condensation-corrosion processes that dissolved the bedrock and speleothems, abundant chemical and clastic sedimentation phases and flooded lower passages. Following the interception of the cave by surface denudation, a remarkably rich late Quaternary vertebrate fossil assemblage accumulated.
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