Data/hora: 20/05/2024 05:31:47

Provedor de dados: 	42	
País: 	Brazil	
Título: 	Characterization and genesis of waterfalls of the Presidente Figueiredo region, Northeast State of Amazonas, Brazil	
Autores: 	NOGUEIRA,AFONSO C. R.; SARGES,ROSEANE R.	
Data: 	2001-06-01	
Ano: 	2001	
Palavras-chave: 	Waterfalls; Western Amazon; Quaternary tectonics; Pseudokarst.	
Resumo: 	The waterfalls of the Presidente Figueiredo municipality represent a fascinating natural scenery of northeast state of Amazonas, northern Brazil. The falls, generally less than 10m high, are developed on siliciclastic rocks of the Nhamundá (Lower Silurian), and Manacapuru (Upper Silurian - Lower Devonian) formations. Morphological and structural analyses of these features indicate that most of them originated through Quaternary neotectonics and are installed in NE-trending normal fault escarpments. Waterfalls also developed within pseudokarstic features, but are less frequent. The origin of the Presidente Figueiredo waterfalls probably goes back to the Neogene, when the region was submitted to laterization processes associated with a humid climate and a dense rainforest. These conditions favored the development of caves in quartzarenites of the Nhamundá Formation. During the Quaternary, the region was subjected to NE-trending normal faulting which displaced laterite layers, rivers and streams giving rise to waterfalls. These climatic and tectonic phenomena promoted intense relief dissection, as indicated by fault escarpment retreat and cave dismantlement, responsible for the present-day morphologic configuration.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000200012	
Editor: 	Academia Brasileira de Ciências	
Relação: 	10.1590/S0001-37652001000200012	
Formato: 	text/html	
Fonte: 	Anais da Academia Brasileira de Ciências  v.73 n.2 2001	
Fonte: 	info:eu-repo/semantics/openAccess