Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina

The Lower Cretaceous Chachao Formation in the Malargae anticline area consists of wackestone, packstone, and minor grainstone and mudstone rich in benthonic fauna that were deposited in a carbonate ramp. The carbonate diagenesis in the Valanginian Chachao Formation contains many processes with consp...

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Detalles Bibliográficos
Autores principales: Palma, Ricardo Manuel, Bressan, Graciela Susana, Kietzmann, Diego Alejandro
Publicado: 2008
Materias:
Argentina
Carbonate
Diagenesis
Neuquén Basin
Valanginian
anticline
bioclastic sediment
biomineralization
carbonate
cementation
Cretaceous
deposition
diagenesis
meteoric water
petrography
phreatic zone
precipitation (chemistry)
redox potential
Neuquen Basin
South America
Gryphaea
Ostreidae
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v23_n1_p39_Palma
http://hdl.handle.net/20.500.12110/paper_08912556_v23_n1_p39_Palma
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08912556_v23_n1_p39_Palma
record_format dspace
spelling paper:paper_08912556_v23_n1_p39_Palma2023-06-08T15:47:09Z Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina Palma, Ricardo Manuel Bressan, Graciela Susana Kietzmann, Diego Alejandro Argentina Carbonate Diagenesis Neuquén Basin Valanginian anticline bioclastic sediment biomineralization carbonate cementation Cretaceous deposition diagenesis meteoric water petrography phreatic zone precipitation (chemistry) redox potential Argentina Neuquen Basin South America Gryphaea Ostreidae The Lower Cretaceous Chachao Formation in the Malargae anticline area consists of wackestone, packstone, and minor grainstone and mudstone rich in benthonic fauna that were deposited in a carbonate ramp. The carbonate diagenesis in the Valanginian Chachao Formation contains many processes with conspicuous effects, including micritization, dissolution, neomorphism, and cementation. The early diagenetic process is characterized by micritization, dissolution and mineralogic stabilization of components, and earlier cement phase represented by micrite cement and isopachous calcite cement, which have petrographic characteristics consistent with precipitation in a marine-phreatic diagenetic environment. Later diagenctic phenomena include granular calcite and syntaxial cement. Both of cement types are interpreted as typical of a meteoric-phreatic environment. Concentric-zoning pattern of alternating dull, and blotchy- to bright luminescent zones is interpreted as being caused by a decrease in redox potential (Eh), under conditions of a progressive marine burial meteoric-phreatic diagenctic environment. Geochemical data (Sr++, Na+, Mg++. Fe++, Mn++) and SEM features of the micrite suggest that original calcareous mud could have been calcite dominated (CDP). The δ18O composition of the granular calcite cement ranging from -2.84‰ to -4.27‰ PDB and the δ13C values of the cement between -2.46‰ and -3.50‰ PDB are compatible with precipitation from a fluid that evolved meteoric-phreatic composition. The high depleted δ 18O values of the Gryphaea oyster shells can be related to the dilution of the marine water with a fresh water influx, whereas shells with the heaviest δ13C isotopic compositions are probably related to the original marine signal, which suggest a closed diagenetic system for carbon. Fil:Palma, R.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Bressan, G.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Kietzmann, D.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v23_n1_p39_Palma http://hdl.handle.net/20.500.12110/paper_08912556_v23_n1_p39_Palma
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Argentina
Carbonate
Diagenesis
Neuquén Basin
Valanginian
anticline
bioclastic sediment
biomineralization
carbonate
cementation
Cretaceous
deposition
diagenesis
meteoric water
petrography
phreatic zone
precipitation (chemistry)
redox potential
Argentina
Neuquen Basin
South America
Gryphaea
Ostreidae
spellingShingle Argentina
Carbonate
Diagenesis
Neuquén Basin
Valanginian
anticline
bioclastic sediment
biomineralization
carbonate
cementation
Cretaceous
deposition
diagenesis
meteoric water
petrography
phreatic zone
precipitation (chemistry)
redox potential
Argentina
Neuquen Basin
South America
Gryphaea
Ostreidae
Palma, Ricardo Manuel
Bressan, Graciela Susana
Kietzmann, Diego Alejandro
Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
topic_facet Argentina
Carbonate
Diagenesis
Neuquén Basin
Valanginian
anticline
bioclastic sediment
biomineralization
carbonate
cementation
Cretaceous
deposition
diagenesis
meteoric water
petrography
phreatic zone
precipitation (chemistry)
redox potential
Argentina
Neuquen Basin
South America
Gryphaea
Ostreidae
description The Lower Cretaceous Chachao Formation in the Malargae anticline area consists of wackestone, packstone, and minor grainstone and mudstone rich in benthonic fauna that were deposited in a carbonate ramp. The carbonate diagenesis in the Valanginian Chachao Formation contains many processes with conspicuous effects, including micritization, dissolution, neomorphism, and cementation. The early diagenetic process is characterized by micritization, dissolution and mineralogic stabilization of components, and earlier cement phase represented by micrite cement and isopachous calcite cement, which have petrographic characteristics consistent with precipitation in a marine-phreatic diagenetic environment. Later diagenctic phenomena include granular calcite and syntaxial cement. Both of cement types are interpreted as typical of a meteoric-phreatic environment. Concentric-zoning pattern of alternating dull, and blotchy- to bright luminescent zones is interpreted as being caused by a decrease in redox potential (Eh), under conditions of a progressive marine burial meteoric-phreatic diagenctic environment. Geochemical data (Sr++, Na+, Mg++. Fe++, Mn++) and SEM features of the micrite suggest that original calcareous mud could have been calcite dominated (CDP). The δ18O composition of the granular calcite cement ranging from -2.84‰ to -4.27‰ PDB and the δ13C values of the cement between -2.46‰ and -3.50‰ PDB are compatible with precipitation from a fluid that evolved meteoric-phreatic composition. The high depleted δ 18O values of the Gryphaea oyster shells can be related to the dilution of the marine water with a fresh water influx, whereas shells with the heaviest δ13C isotopic compositions are probably related to the original marine signal, which suggest a closed diagenetic system for carbon.
author Palma, Ricardo Manuel
Bressan, Graciela Susana
Kietzmann, Diego Alejandro
author_facet Palma, Ricardo Manuel
Bressan, Graciela Susana
Kietzmann, Diego Alejandro
author_sort Palma, Ricardo Manuel
title Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
title_short Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
title_full Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
title_fullStr Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
title_full_unstemmed Diagenesis of a bioclastic oyster deposit from the Lower Cretaceous (Chachao Formation). Neuquén Basin. Mendoza Province, Argentina
title_sort diagenesis of a bioclastic oyster deposit from the lower cretaceous (chachao formation). neuquén basin. mendoza province, argentina
publishDate 2008
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v23_n1_p39_Palma
http://hdl.handle.net/20.500.12110/paper_08912556_v23_n1_p39_Palma
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AT bressangracielasusana diagenesisofabioclasticoysterdepositfromthelowercretaceouschachaoformationneuquenbasinmendozaprovinceargentina
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