(U)SAXS characterization of porous microstructure of chert : insights into organic matter preservation.

Registro completo de metadados
MetadadosDescriçãoIdioma
Autor(es): dc.creatorMunoz, Patricio-
Autor(es): dc.creatorIlavsky, Jan-
Autor(es): dc.creatorNewville, Matthew-
Autor(es): dc.creatorWetter, Niklaus Ursus-
Autor(es): dc.creatorLourenço, Rafael André-
Autor(es): dc.creatorAndrade, Marcelo Barbosa de-
Autor(es): dc.creatorMartins, Tereza da Silva-
Autor(es): dc.creatorDipold, Jessica-
Autor(es): dc.creatorFreitas, Anderson Zanardi de-
Autor(es): dc.creatorSilva, Luis Carlos Cides da-
Autor(es): dc.creatorOliveira, Cristiano Luis Pinto-
Data de aceite: dc.date.accessioned2025-08-21T15:41:01Z-
Data de disponibilização: dc.date.available2025-08-21T15:41:01Z-
Data de envio: dc.date.issued2025-01-07-
Data de envio: dc.date.issued2025-01-07-
Data de envio: dc.date.issued2022-
Fonte completa do material: dc.identifierhttps://www.repositorio.ufop.br/handle/123456789/19395-
Fonte completa do material: dc.identifierhttps://doi.org/10.1107/S1600576723008889-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/capes/1021488-
Descrição: dc.descriptionThis study characterizes the microstructure and mineralogy of 132 (ODP sample), 1000 and 1880 million-year-old chert samples. By using ultra-small angle X-ray scattering (USAXS), wide-angle X-ray scattering and other techniques, the preservation of organic matter (OM) in these samples is studied. The scarce microstructural data reported on chert contrast with many studies addressing porosity evolution in other sedimentary rocks. The aim of this work is to solve the distribution of OM and silica in chert by characterizing samples before and after combustion to pinpoint the OM distribution inside the porous silica matrix. The samples are predominantly composed of alpha quartz and show increasing crystallite sizes up to 33 5 nm (1 standard deviation or SD). In older samples, low water abundances ( 0.03%) suggest progressive dehydration. (U)SAXS data reveal a porous matrix that evolves over geological time, including, from younger to older samples, (1) a decreasing pore volume down to 1%, (2) greater pore sizes hosting OM, (3) decreasing specific surface area values from younger (9.3 0.1 m2 g 1) to older samples (0.63 0.07 m2 g 1, 1 SD) and (4) a lower background intensity correlated todecreasing hydrogen abundances. The pore-volume distributions (PVDs) showthat pores ranging from 4 to 100 nm accumulate the greater volume fraction of OM. Raman data show aromatic organic clusters up to 20 nm in older samples. Raman and PVD data suggest that OM is located mostly in mesopores. Observed structural changes, silica–OM interactions and the hydrophobicity of the OM could explain the OM preservation in chert-
Formato: dc.formatapplication/pdf-
Idioma: dc.languageen-
Direitos: dc.rightsaberto-
Direitos: dc.rightsThis is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/bync/4.0/). Fonte: PDF do artigo.-
Palavras-chave: dc.subjectSilica-rich sedimentary rocks-
Palavras-chave: dc.subjectCherts-
Palavras-chave: dc.subjectOrganic matter-
Palavras-chave: dc.subjectUltra-small-angle X-ray scattering-
Palavras-chave: dc.subjectWide-angle X-ray scattering-
Título: dc.title(U)SAXS characterization of porous microstructure of chert : insights into organic matter preservation.-
Aparece nas coleções:Repositório Institucional - UFOP

Não existem arquivos associados a este item.