Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes

At 32° 40′ south latitude the Andean orogen shows a typical thin-skinned fold and thrust belt that exposes the Mesozoic back-arc basin fill. The late Callovian - early Oxfordian limestones of the La Manga Formation were studied based on lithofacies, microfacies, and diagenetic processes in order to...

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Detalles Bibliográficos
Publicado: 2002
Materias:
Callovian
carbonate system
depositional environment
diagenesis
eustacy
lithofacies
microfacies
Oxfordian
Andes
Argentina
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v17_n1_p1_LoForte
http://hdl.handle.net/20.500.12110/paper_08912556_v17_n1_p1_LoForte
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08912556_v17_n1_p1_LoForte
record_format dspace
spelling paper:paper_08912556_v17_n1_p1_LoForte2023-06-08T15:47:09Z Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes Callovian carbonate system depositional environment diagenesis eustacy lithofacies microfacies Oxfordian Andes Argentina At 32° 40′ south latitude the Andean orogen shows a typical thin-skinned fold and thrust belt that exposes the Mesozoic back-arc basin fill. The late Callovian - early Oxfordian limestones of the La Manga Formation were studied based on lithofacies, microfacies, and diagenetic processes in order to interpret the paleoenvironment depositional setting. Five lithofacies can be recognized within the La Manga Formation: (A) stromatolite mudstone, (B) massive and laminated carbonate mudstone, (C) massive wackestone, (D) coralline floatstone, and (E) oolitic-skeletal packstone-grainstone. The vertical succession reveals six closely related microfacies grouped as follows: (1) stromatolite mudstone, (2) peloidal wackestone, (3) bioclastic peloidal wackestone, (4) oolitic bioclastic packstone, (5) coral skeletal floatstone, and (6) oolitic-intraclastic grainstone. Diagenetic events, listed in sequence, include: 1) dissolution of high-Mg calcite and aragonite shells; 2) compaction; 3) pore filling; and 4) pressure-solution. Three types of cement, isopachous, granular calcite and syntaxial overgrowth, were identified. Based on CL petrography the cement sequence changes from non-luminescent to brightly luminescent, suggesting variations within the pore fluid system. Paleotemperature during deposition is estimated at 26°C according to stable isotope analyses on oyster shells. Lithofacies and microfacies data suggest that an intertidal-lower supratidal environment (lithofacies A and microfacies 1) was followed by a deepening succession (lithofacies B, C, and microfacies 2, 3), followed by a shallowing upward succession (lithofacies D, E, and microfacies 2,3), followed by a shallowing upward succession (lithofacies D, E, and microfacies 4, 5, 6). This facies assemblage is interpreted as part of a transgressive system tract and a high-stand succession. The sequence represents an upward-coarsening deposit on a shallow carbonate platform. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v17_n1_p1_LoForte http://hdl.handle.net/20.500.12110/paper_08912556_v17_n1_p1_LoForte
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Callovian
carbonate system
depositional environment
diagenesis
eustacy
lithofacies
microfacies
Oxfordian
Andes
Argentina
spellingShingle Callovian
carbonate system
depositional environment
diagenesis
eustacy
lithofacies
microfacies
Oxfordian
Andes
Argentina
Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
topic_facet Callovian
carbonate system
depositional environment
diagenesis
eustacy
lithofacies
microfacies
Oxfordian
Andes
Argentina
description At 32° 40′ south latitude the Andean orogen shows a typical thin-skinned fold and thrust belt that exposes the Mesozoic back-arc basin fill. The late Callovian - early Oxfordian limestones of the La Manga Formation were studied based on lithofacies, microfacies, and diagenetic processes in order to interpret the paleoenvironment depositional setting. Five lithofacies can be recognized within the La Manga Formation: (A) stromatolite mudstone, (B) massive and laminated carbonate mudstone, (C) massive wackestone, (D) coralline floatstone, and (E) oolitic-skeletal packstone-grainstone. The vertical succession reveals six closely related microfacies grouped as follows: (1) stromatolite mudstone, (2) peloidal wackestone, (3) bioclastic peloidal wackestone, (4) oolitic bioclastic packstone, (5) coral skeletal floatstone, and (6) oolitic-intraclastic grainstone. Diagenetic events, listed in sequence, include: 1) dissolution of high-Mg calcite and aragonite shells; 2) compaction; 3) pore filling; and 4) pressure-solution. Three types of cement, isopachous, granular calcite and syntaxial overgrowth, were identified. Based on CL petrography the cement sequence changes from non-luminescent to brightly luminescent, suggesting variations within the pore fluid system. Paleotemperature during deposition is estimated at 26°C according to stable isotope analyses on oyster shells. Lithofacies and microfacies data suggest that an intertidal-lower supratidal environment (lithofacies A and microfacies 1) was followed by a deepening succession (lithofacies B, C, and microfacies 2, 3), followed by a shallowing upward succession (lithofacies D, E, and microfacies 2,3), followed by a shallowing upward succession (lithofacies D, E, and microfacies 4, 5, 6). This facies assemblage is interpreted as part of a transgressive system tract and a high-stand succession. The sequence represents an upward-coarsening deposit on a shallow carbonate platform.
title Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
title_short Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
title_full Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
title_fullStr Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
title_full_unstemmed Facies, microfacies, and diagenesis of late Callovian-early Oxfordian carbonates (La Manga Formation) in the West Central Argentinean high andes
title_sort facies, microfacies, and diagenesis of late callovian-early oxfordian carbonates (la manga formation) in the west central argentinean high andes
publishDate 2002
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08912556_v17_n1_p1_LoForte
http://hdl.handle.net/20.500.12110/paper_08912556_v17_n1_p1_LoForte
_version_ 1768542182001606656

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