Data/hora: 11/06/2024 14:06:22

Provedor de dados: 	90	
País: 	Brazil	
Título: 	Weathering of Rhyolites and Soil Formation in an Atlantic Forest Fragment in Northeastern Brazil	
Autores: 	Brilhante,Stephany Alves; Santos,Jean Cheyson Barros dos; Souza Júnior,Valdomiro Severino de; Araújo,Jane Kelly Silva; Ribeiro Filho,Mateus Rosas; Corrêa,Marcelo Metri.	
Data: 	2017-01-01	
Ano: 	2017	
Palavras-chave: 	Pedogenesis; Halloysite; Toposequence; Acid crystalline rock.	
Resumo: 	ABSTRACT Weathering and pedogenesis have been studied for a wide range of rocks and climates around the world. However, the eruption of rhyolitic magmas is a rare geological event, which leads to few studies associated with the rhyolite-soil-landscape relationship. In this context, this study evaluated the influence of rhyolite weathering on the properties of soils along a slope in an Atlantic Forest environment in the state of Pernambuco, northeastern Brazil. Four weathering profiles derived from rhyolites were classified and sampled for chemical, physical, mineralogical, micromorphological, differential thermal, and thermogravimetric analyses. The chemical properties reflect the original rock rich in felsic minerals, poor in bases, and the types of clay minerals. The clay fraction of the profiles consists mainly of 1:1 phyllosilicates and oxides, indicating intermediate weathering. However, variations in the degree of structure weathering were evidenced by the presence of partially preserved fragments of the original rock in the sand fraction of the soils. The tropical humid climate of the region influenced conversion of hematite to goethite through the xanthization process, and the subsurface drainage deficiency allowed the formation of halloysite in the lowest position of the landscape. Because it is an acid rock with an aphanitic texture and porphyritic relative size of crystals, rhyolite weathering resulted in the formation of dystrophic soils, with predominance of quartz in the silt fraction. From the top to the lower third of the slope, a Haplic Cambisol, an Abruptic Lixisol, and two Haplic Lixisols were formed.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100312	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/18069657rbcs20160558	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.41 2017	
Fonte: 	info:eu-repo/semantics/openAccess