Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography

Paleoenvironmental analysis of the Cenozoic marine section cropping out near Gaiman (Chubut Province, Argentina) shows that most of the local succession was deposited in a shallow, storm-dominated marine environment, bearing well preserved Ophiomorpha fossil traces. Sequence-stratigraphic interpreta...

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Detalles Bibliográficos
Autores principales: Scasso, R.A., Castro, L.N.
Formato: JOUR
Materias:
Argentina
Cenozoic
Pal eoceanography
Patagonia
Patagoniense
Phosphates
Phosphogenesis
Sequence-stratigraphy
marine environment
paleoceanography
phosphate
sequence stratigraphy
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v12_n5_p471_Scasso
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_08959811_v12_n5_p471_Scasso2023-10-03T15:42:29Z Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography Scasso, R.A. Castro, L.N. Argentina Cenozoic Pal eoceanography Patagonia Patagoniense Phosphates Phosphogenesis Sequence-stratigraphy Cenozoic marine environment paleoceanography phosphate sequence stratigraphy Argentina Paleoenvironmental analysis of the Cenozoic marine section cropping out near Gaiman (Chubut Province, Argentina) shows that most of the local succession was deposited in a shallow, storm-dominated marine environment, bearing well preserved Ophiomorpha fossil traces. Sequence-stratigraphic interpretation records the effect of three sea-level oscillations. Phosphatic strata are related to mostly in situ concretions developed within transgressive-early highstand system tracts (Type 1) and to reworked and winnowed lags associated with transgressive surfaces (Type 2) which display a concentration of phosphatic concretions, ooids, vertebrate bones, teeth and shells. Close association of Callianasid bioturbation (Ophiomorpha) and phosphatic levels suggest a genetic link for both, via improved early-diagenetic water circulation and Fe and P early-diagenetic cycling. Phosphogenesis would have taken place after cold and corrosive water, probably similar to the present Antarctic Intermediate Water (AAIW), flooded the continental shelf and mixed with warmer surficial waters. This mixing could explain the contrasting indications from the marine vertebrate fauna together with the general corrosion and replacement processes that are common in the Gaiman strata. The development of the phosphorites would have occurred at times of global climatic transition and increased oceanic circulation, probably during the Late Oligocene Early Miocene. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v12_n5_p471_Scasso
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
Cenozoic
Pal eoceanography
Patagonia
Patagoniense
Phosphates
Phosphogenesis
Sequence-stratigraphy
Cenozoic
marine environment
paleoceanography
phosphate
sequence stratigraphy
Argentina
spellingShingle Argentina
Cenozoic
Pal eoceanography
Patagonia
Patagoniense
Phosphates
Phosphogenesis
Sequence-stratigraphy
Cenozoic
marine environment
paleoceanography
phosphate
sequence stratigraphy
Argentina
Scasso, R.A.
Castro, L.N.
Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
topic_facet Argentina
Cenozoic
Pal eoceanography
Patagonia
Patagoniense
Phosphates
Phosphogenesis
Sequence-stratigraphy
Cenozoic
marine environment
paleoceanography
phosphate
sequence stratigraphy
Argentina
description Paleoenvironmental analysis of the Cenozoic marine section cropping out near Gaiman (Chubut Province, Argentina) shows that most of the local succession was deposited in a shallow, storm-dominated marine environment, bearing well preserved Ophiomorpha fossil traces. Sequence-stratigraphic interpretation records the effect of three sea-level oscillations. Phosphatic strata are related to mostly in situ concretions developed within transgressive-early highstand system tracts (Type 1) and to reworked and winnowed lags associated with transgressive surfaces (Type 2) which display a concentration of phosphatic concretions, ooids, vertebrate bones, teeth and shells. Close association of Callianasid bioturbation (Ophiomorpha) and phosphatic levels suggest a genetic link for both, via improved early-diagenetic water circulation and Fe and P early-diagenetic cycling. Phosphogenesis would have taken place after cold and corrosive water, probably similar to the present Antarctic Intermediate Water (AAIW), flooded the continental shelf and mixed with warmer surficial waters. This mixing could explain the contrasting indications from the marine vertebrate fauna together with the general corrosion and replacement processes that are common in the Gaiman strata. The development of the phosphorites would have occurred at times of global climatic transition and increased oceanic circulation, probably during the Late Oligocene Early Miocene.
format JOUR
author Scasso, R.A.
Castro, L.N.
author_facet Scasso, R.A.
Castro, L.N.
author_sort Scasso, R.A.
title Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
title_short Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
title_full Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
title_fullStr Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
title_full_unstemmed Cenozoic phosphatic deposits in North Patagonia, Argentina: Phosphogenesis, sequence-stratigraphy and paleoceanography
title_sort cenozoic phosphatic deposits in north patagonia, argentina: phosphogenesis, sequence-stratigraphy and paleoceanography
url http://hdl.handle.net/20.500.12110/paper_08959811_v12_n5_p471_Scasso
work_keys_str_mv AT scassora cenozoicphosphaticdepositsinnorthpatagoniaargentinaphosphogenesissequencestratigraphyandpaleoceanography
AT castroln cenozoicphosphaticdepositsinnorthpatagoniaargentinaphosphogenesissequencestratigraphyandpaleoceanography
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