干旱区生态环境知识资源中心(Arid): Tufa associated with karst features in a fracture-system fed by meteoric water, Araripe basin, NE Brazil

Arid

DOI	10.1016/j.jsames.2022.103772
	Tufa associated with karst features in a fracture-system fed by meteoric water, Araripe basin, NE Brazil
	Diniz, Jaqueline Lopes; Wohnrath Tognoli, Francisco Manoel; Claes, Hannes; de Miranda, Tiago Siqueira; de Miranda Lopes Neumann, Virginio Henrique; Sial, Alcides Nobrega; Inocencio, Leonardo Campos; de Souza, Lais Vieira
通讯作者	Tognoli, FMW
来源期刊	JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
ISSN	0895-9811
EISSN	1873-0647
出版年	2022
卷号	115
英文摘要	Karstic tufa from the Brazilian semi-arid zone offers a key opportunity to study the depositional evolution, unveiling the past climate history with examples generated outside of the phreatic zone. Morpho-petrological identification, in addition to a structural survey, petrographic analysis, X-ray diffractometry (XRD), scanning electronic microscopy (SEM), and measurements of 818O and 813C, provided elements to explain the occurrence of tufa associated with a fracture system. Three sedimentary facies were identified, one allochthonous (detrital) and two autochthonous (in situ). Field recognition and structural analysis showed that tufa occurs only in the deformed portion of the Crato Formation, at the Triunfo Fault splay sector. Facies formed in an open fracturecontrolled hydrological system during rainfall periods. The infiltration of meteoric water into the limestones of the Crato Formation facilitated the dissolution of the parent rock through time, with the percolation controlled by open fractures in tilted blocks. Breccia tufa developed in the early stage of the karstification by carbonate clast forming from the limestone, previously collapsed from the walls and later cemented by percolation of solutions enriched in calcium carbonate within fractures. The two autochthonous facies developed in later stages through continuous percolation of water, rock dissolution, bryophyte-microbial growth, soil development, and calcium carbonate precipitation in progressively more humid conditions. Thin section analyses and SEM imaging revealed calcite crystals closely related with organic structures. The association between tufa and microbial filamentous organisms (likely cyanobacteria) indicates an active biogenic role for the tufa origin. Calcite stableisotopes analyses indicated tufa as a product of meteoric water as supported by 818O isotope. Changes of the carbon ratios through time indicated influence of soil development and probably C3-C4 photosynthetic activity. An integrated structural, sedimentological, petrological, and geochemical approach provided elements to define these tufa deposits as formed in a fracture-system fed by meteoric water, as result of the post-Mesozoic denudation process that affected the Araripe Basin.
英文关键词	Crato formation Breccia tufa Microbially-influenced tufa Semi-arid climate C3-C4 photosynthesis Digital outcrop model
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000792102400001
WOS关键词	CRATO FORMATION ; TRAVERTINE ; CARBONATE ; DEPOSITS ; ORIGIN ; CLASSIFICATION ; RECONSTRUCTION ; PHOTOGRAMMETRY ; SEDIMENTOLOGY ; ISLAND
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/393594
推荐引用方式 GB/T 7714	Diniz, Jaqueline Lopes,Wohnrath Tognoli, Francisco Manoel,Claes, Hannes,et al. Tufa associated with karst features in a fracture-system fed by meteoric water, Araripe basin, NE Brazil[J],2022,115.
APA	Diniz, Jaqueline Lopes.,Wohnrath Tognoli, Francisco Manoel.,Claes, Hannes.,de Miranda, Tiago Siqueira.,de Miranda Lopes Neumann, Virginio Henrique.,...&de Souza, Lais Vieira.(2022).Tufa associated with karst features in a fracture-system fed by meteoric water, Araripe basin, NE Brazil.JOURNAL OF SOUTH AMERICAN EARTH SCIENCES,115.
MLA	Diniz, Jaqueline Lopes,et al."Tufa associated with karst features in a fracture-system fed by meteoric water, Araripe basin, NE Brazil".JOURNAL OF SOUTH AMERICAN EARTH SCIENCES 115(2022).