Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica

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The Eocene La Meseta Formation is the youngest exposed unit of the back-arc James Ross Basin, Antarctic Peninsula, cropping out in Seymour (Marambio) Island. The formation comprises 720 m of clastic sedimentary rocks of deltaic, estuarine and shallow marine origin. It was subdivided into six unconfo...

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Autores principales: Marenssi, S.A., Net, L.I., Santillana, S.N.
Formato: JOUR
Materias:
Antarctica
Eocene
Incised-valley systems
Petrofacies
Sandstones
Sedimentary petrography
backarc basin
clastic rock
coastal sediment
facies analysis
petrography
provenance
environment
eocene
facies (geology)
geology
island (geological)
La Meseta Formation
nutrient cycling
rock
sedimentation
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00370738_v150_n3-4_p301_Marenssi
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00370738_v150_n3-4_p301_Marenssi2023-10-03T14:47:59Z Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica Marenssi, S.A. Net, L.I. Santillana, S.N. Antarctica Eocene Incised-valley systems Petrofacies Sandstones Sedimentary petrography backarc basin clastic rock coastal sediment Eocene facies analysis petrography provenance Antarctica environment eocene facies (geology) geology island (geological) La Meseta Formation nutrient cycling rock sedimentation Antarctica The Eocene La Meseta Formation is the youngest exposed unit of the back-arc James Ross Basin, Antarctic Peninsula, cropping out in Seymour (Marambio) Island. The formation comprises 720 m of clastic sedimentary rocks of deltaic, estuarine and shallow marine origin. It was subdivided into six unconformity-based units (Valle de Las Focas, Acantilados, Campamento, Cucullaea I, Cucullaea II and Submeseta Allomembers) grouped into three main facies associations. Facies association I represents valley-confined deposition in a progradational/aggradational tide-dominated and wave-influenced delta front/delta plain environment. Facies association II includes tidal channels, mixed tidal flats, tidal inlets and deltas, washover and beach environments. Facies association III represents nonconfined tide- and storm-influenced nearshore environments. La Meseta Formation sandstones are quartzofeldspathic with some hybrid arenites (glauconite and carbonate bioclasts-rich). Sandstone detrital modes are subdivided into two distinctive petrofacies: the low quartz petrofacies (petrofacies I, Q < 55% and L > 12%), interpreted to retain the original provenance signal, and the high quartz petrofacies (petrofacies II, Q>55% and L < 12%), representing the reworking product of the former after selective elimination of the more labile components. Petrofacies I sandstone framework grains were mainly derived from a dissected magmatic arc and an associated metamorphic belt. Textural evidence for recycling of some grains (e.g. garnet) from older sedimentary units during valley incision is not conclusive. Changes in the relative participation of source areas during the evolution of the incised-valley system are evaluated from the relative proportions of lithic fragments and monomineralic clasts derived from each rock type. Two lithic assemblages were recognized. The mixed lithic assemblage (Rv/Rm + Rp < 1.4) shows participation of all rock types; it represented valley-confined environments, either during the initial stage of valley development, or after main episodes of incision. The volcanic lithic assemblage (Rv/Rm + Rp>1.4) is clearly dominated by volcanic-derived clasts; it developed at times of high sea level and/or during later stages of the valley fill, when an "energy fence" at the shoreline prevented delivery of sediment from the Antarctic Peninsula, thus enhancing the relative participation of local volcanic sources. © 2002 Elsevier Science B.V. All rights reserved. Fil:Marenssi, S.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Net, L.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Santillana, S.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00370738_v150_n3-4_p301_Marenssi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Antarctica
Eocene
Incised-valley systems
Petrofacies
Sandstones
Sedimentary petrography
backarc basin
clastic rock
coastal sediment
Eocene
facies analysis
petrography
provenance
Antarctica
environment
eocene
facies (geology)
geology
island (geological)
La Meseta Formation
nutrient cycling
rock
sedimentation
Antarctica
spellingShingle Antarctica
Eocene
Incised-valley systems
Petrofacies
Sandstones
Sedimentary petrography
backarc basin
clastic rock
coastal sediment
Eocene
facies analysis
petrography
provenance
Antarctica
environment
eocene
facies (geology)
geology
island (geological)
La Meseta Formation
nutrient cycling
rock
sedimentation
Antarctica
Marenssi, S.A.
Net, L.I.
Santillana, S.N.
Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
topic_facet Antarctica
Eocene
Incised-valley systems
Petrofacies
Sandstones
Sedimentary petrography
backarc basin
clastic rock
coastal sediment
Eocene
facies analysis
petrography
provenance
Antarctica
environment
eocene
facies (geology)
geology
island (geological)
La Meseta Formation
nutrient cycling
rock
sedimentation
Antarctica
description The Eocene La Meseta Formation is the youngest exposed unit of the back-arc James Ross Basin, Antarctic Peninsula, cropping out in Seymour (Marambio) Island. The formation comprises 720 m of clastic sedimentary rocks of deltaic, estuarine and shallow marine origin. It was subdivided into six unconformity-based units (Valle de Las Focas, Acantilados, Campamento, Cucullaea I, Cucullaea II and Submeseta Allomembers) grouped into three main facies associations. Facies association I represents valley-confined deposition in a progradational/aggradational tide-dominated and wave-influenced delta front/delta plain environment. Facies association II includes tidal channels, mixed tidal flats, tidal inlets and deltas, washover and beach environments. Facies association III represents nonconfined tide- and storm-influenced nearshore environments. La Meseta Formation sandstones are quartzofeldspathic with some hybrid arenites (glauconite and carbonate bioclasts-rich). Sandstone detrital modes are subdivided into two distinctive petrofacies: the low quartz petrofacies (petrofacies I, Q < 55% and L > 12%), interpreted to retain the original provenance signal, and the high quartz petrofacies (petrofacies II, Q>55% and L < 12%), representing the reworking product of the former after selective elimination of the more labile components. Petrofacies I sandstone framework grains were mainly derived from a dissected magmatic arc and an associated metamorphic belt. Textural evidence for recycling of some grains (e.g. garnet) from older sedimentary units during valley incision is not conclusive. Changes in the relative participation of source areas during the evolution of the incised-valley system are evaluated from the relative proportions of lithic fragments and monomineralic clasts derived from each rock type. Two lithic assemblages were recognized. The mixed lithic assemblage (Rv/Rm + Rp < 1.4) shows participation of all rock types; it represented valley-confined environments, either during the initial stage of valley development, or after main episodes of incision. The volcanic lithic assemblage (Rv/Rm + Rp>1.4) is clearly dominated by volcanic-derived clasts; it developed at times of high sea level and/or during later stages of the valley fill, when an "energy fence" at the shoreline prevented delivery of sediment from the Antarctic Peninsula, thus enhancing the relative participation of local volcanic sources. © 2002 Elsevier Science B.V. All rights reserved.
format JOUR
author Marenssi, S.A.
Net, L.I.
Santillana, S.N.
author_facet Marenssi, S.A.
Net, L.I.
Santillana, S.N.
author_sort Marenssi, S.A.
title Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
title_short Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
title_full Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
title_fullStr Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
title_full_unstemmed Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: The Eocene La Meseta Formation, Seymour Island, Antarctica
title_sort provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: the eocene la meseta formation, seymour island, antarctica
url http://hdl.handle.net/20.500.12110/paper_00370738_v150_n3-4_p301_Marenssi
work_keys_str_mv AT marenssisa provenanceenvironmentalandpaleogeographiccontrolsonsandstonecompositioninanincisedvalleysystemtheeocenelamesetaformationseymourislandantarctica
AT netli provenanceenvironmentalandpaleogeographiccontrolsonsandstonecompositioninanincisedvalleysystemtheeocenelamesetaformationseymourislandantarctica
AT santillanasn provenanceenvironmentalandpaleogeographiccontrolsonsandstonecompositioninanincisedvalleysystemtheeocenelamesetaformationseymourislandantarctica
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