Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province

Studies carried out in different outcrops of La Manga Formation (middle Callovian-middle Oxfordian) in southern Mendoza province, have allowed the recognition of an internal discontinuity characterized by the presence of a paleokarst. This surface was mentioned by Groeber as alveolar limestones. He...

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Autores principales: Palma, R.M., Bressan, G.S., López-Gómez, J., Martín Chivelet, J.M., Kietzmann, D.A.
Formato: JOUR
Materias:
Collapse
Epikarst
Mantiform breccias
Sinkhole
breccia
Callovian
diagenesis
dissolution
facies analysis
limestone
morphology
Oxfordian
paleokarst
petrofabric
sedimentology
sinkhole
Argentina
Mendoza
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00044822_v74_n1_p40_Palma
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00044822_v74_n1_p40_Palma
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spelling todo:paper_00044822_v74_n1_p40_Palma2023-10-03T13:59:15Z Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province Palma, R.M. Bressan, G.S. López-Gómez, J. Martín Chivelet, J.M. Kietzmann, D.A. Collapse Epikarst Mantiform breccias Sinkhole breccia Callovian diagenesis dissolution facies analysis limestone morphology Oxfordian paleokarst petrofabric sedimentology sinkhole Argentina Mendoza Studies carried out in different outcrops of La Manga Formation (middle Callovian-middle Oxfordian) in southern Mendoza province, have allowed the recognition of an internal discontinuity characterized by the presence of a paleokarst. This surface was mentioned by Groeber as alveolar limestones. He also recognized surfaces displaying shades of yellow, brown alteration colors and honeycomb erosion (alveolation processes) in the “blue limestones wih Gryphaea”. These surfaces appear on the top of reefal and oolitic barrier facies which define a shallowing-upward succession, or in intertidal-supratidal facies. Paleokarst deposits are represented by mantling breccias, collapse breccias and sinkhole breccias. Breccias are chaotic, with grain-supported to matrix supported fabrics. Some breccias can appear stratified. They are composed by clasts that vary between few millimeters to boulders, with irregular limits produced by dissolution. Sedimentology, morphology and diagenesis let recognize the epikarst in peritidal facies showing shorten shallowing-upward cycles in an internal ramp with low gradient. Fluctuations of the phreatic level during periods of subaerial exposure controlled the development of pendant cementation and drusy calcite cement with negative values of δ18O (-5.08 to-6.21‰) evidencing the action of meteoric waters. The epikarst shows dissolution cavities that reach 3 to 5 cm below surface, usually indicated by the presence of iron oxides and pisolites with an irregular distribution. The discontinuity is indicated by the paleokarst and by epikarst features, which are produced by subareal exposure and intense dissolution processes as a consequence of sea level fall. © 2017, Asociacion Geologica Argentina. All rights reserved. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00044822_v74_n1_p40_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 Collapse
Epikarst
Mantiform breccias
Sinkhole
breccia
Callovian
diagenesis
dissolution
facies analysis
limestone
morphology
Oxfordian
paleokarst
petrofabric
sedimentology
sinkhole
Argentina
Mendoza
spellingShingle Collapse
Epikarst
Mantiform breccias
Sinkhole
breccia
Callovian
diagenesis
dissolution
facies analysis
limestone
morphology
Oxfordian
paleokarst
petrofabric
sedimentology
sinkhole
Argentina
Mendoza
Palma, R.M.
Bressan, G.S.
López-Gómez, J.
Martín Chivelet, J.M.
Kietzmann, D.A.
Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
topic_facet Collapse
Epikarst
Mantiform breccias
Sinkhole
breccia
Callovian
diagenesis
dissolution
facies analysis
limestone
morphology
Oxfordian
paleokarst
petrofabric
sedimentology
sinkhole
Argentina
Mendoza
description Studies carried out in different outcrops of La Manga Formation (middle Callovian-middle Oxfordian) in southern Mendoza province, have allowed the recognition of an internal discontinuity characterized by the presence of a paleokarst. This surface was mentioned by Groeber as alveolar limestones. He also recognized surfaces displaying shades of yellow, brown alteration colors and honeycomb erosion (alveolation processes) in the “blue limestones wih Gryphaea”. These surfaces appear on the top of reefal and oolitic barrier facies which define a shallowing-upward succession, or in intertidal-supratidal facies. Paleokarst deposits are represented by mantling breccias, collapse breccias and sinkhole breccias. Breccias are chaotic, with grain-supported to matrix supported fabrics. Some breccias can appear stratified. They are composed by clasts that vary between few millimeters to boulders, with irregular limits produced by dissolution. Sedimentology, morphology and diagenesis let recognize the epikarst in peritidal facies showing shorten shallowing-upward cycles in an internal ramp with low gradient. Fluctuations of the phreatic level during periods of subaerial exposure controlled the development of pendant cementation and drusy calcite cement with negative values of δ18O (-5.08 to-6.21‰) evidencing the action of meteoric waters. The epikarst shows dissolution cavities that reach 3 to 5 cm below surface, usually indicated by the presence of iron oxides and pisolites with an irregular distribution. The discontinuity is indicated by the paleokarst and by epikarst features, which are produced by subareal exposure and intense dissolution processes as a consequence of sea level fall. © 2017, Asociacion Geologica Argentina. All rights reserved.
format JOUR
author Palma, R.M.
Bressan, G.S.
López-Gómez, J.
Martín Chivelet, J.M.
Kietzmann, D.A.
author_facet Palma, R.M.
Bressan, G.S.
López-Gómez, J.
Martín Chivelet, J.M.
Kietzmann, D.A.
author_sort Palma, R.M.
title Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
title_short Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
title_full Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
title_fullStr Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
title_full_unstemmed Paleokarst facies in la manga formation (Middle oxfordian), Southern Mendoza province
title_sort paleokarst facies in la manga formation (middle oxfordian), southern mendoza province
url http://hdl.handle.net/20.500.12110/paper_00044822_v74_n1_p40_Palma
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AT bressangs paleokarstfaciesinlamangaformationmiddleoxfordiansouthernmendozaprovince
AT lopezgomezj paleokarstfaciesinlamangaformationmiddleoxfordiansouthernmendozaprovince
AT martinchiveletjm paleokarstfaciesinlamangaformationmiddleoxfordiansouthernmendozaprovince
AT kietzmannda paleokarstfaciesinlamangaformationmiddleoxfordiansouthernmendozaprovince
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