Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina
Griphaeid-dominated fossil concentrations of La Manga Formation are characterized on the basis of taphonomic, sedimentologic, stratigraphic and palaeoecologic criteria. These concentrations are present in the basal deposits (Unit 1) of three outcrops in the locality of Bardas Blancas. Their attribut...
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16986180_v36_n1_p55_Bressan http://hdl.handle.net/20.500.12110/paper_16986180_v36_n1_p55_Bressan |
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paper:paper_16986180_v36_n1_p55_Bressan2023-06-08T16:26:53Z Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina Bressan, Graciela Susana Palma, Ricardo Manuel Gryphaeids Shell beds Storm deposits Upper jurassic accumulation rate bioturbation bivalve bottom current fossil record geological record hydraulic conductivity Jurassic Oxfordian paleobiogeography reworking sedimentology shell bed taphonomy vertical distribution wave energy Argentina Bardas Blancas Mendoza Gryphaea Gryphaeidae Griphaeid-dominated fossil concentrations of La Manga Formation are characterized on the basis of taphonomic, sedimentologic, stratigraphic and palaeoecologic criteria. These concentrations are present in the basal deposits (Unit 1) of three outcrops in the locality of Bardas Blancas. Their attributes allow distinguishing seven different fossil accumulations: A) Channelized fossil concentrations of Gryphaea sp.; B) Shell beds of Gryphaea sp. highly reworked; C) Shell beds of Gryphaea sp. moderately reworked; D) Accumulations of Gryphaea sp. with biomicrite to biopelmicrite matrix; E) Shell detritus; F) Accumulations produced by bottom currents; and G) Accumulations found in clumps. Accumulations A-C were deposited by high energy processes (storm waves and currents) in the upper middle ramp. Accumulations D and E were produced by high energy processes (storm waves and currents) but the final depositions were produced out of suspension in low energy environments, in lower middle ramp settings. Accumulations F were generated by weak bottom currents, meanwhile accumulations G correspond to gryphaeids associations reworked by bioturbators or by hydraulic processes after variable periods of permanence in sediment/water interface. Both are interpreted as lower middle or outer ramp. This interpretation suggests that these deposits that in previous works were interpreted as outer ramp settings, characterize middle and outer ramp settings. The vertical distribution of fossil concentrations from upper middle ramp to lower middle and outer ramp settings evidences a continuously growing accommodation space and allows to interpret the Unit 1 as part of a transgressive systems tract. Fil:Bressan, G.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Palma, R.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16986180_v36_n1_p55_Bressan http://hdl.handle.net/20.500.12110/paper_16986180_v36_n1_p55_Bressan |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Gryphaeids Shell beds Storm deposits Upper jurassic accumulation rate bioturbation bivalve bottom current fossil record geological record hydraulic conductivity Jurassic Oxfordian paleobiogeography reworking sedimentology shell bed taphonomy vertical distribution wave energy Argentina Bardas Blancas Mendoza Gryphaea Gryphaeidae |
| spellingShingle |
Gryphaeids Shell beds Storm deposits Upper jurassic accumulation rate bioturbation bivalve bottom current fossil record geological record hydraulic conductivity Jurassic Oxfordian paleobiogeography reworking sedimentology shell bed taphonomy vertical distribution wave energy Argentina Bardas Blancas Mendoza Gryphaea Gryphaeidae Bressan, Graciela Susana Palma, Ricardo Manuel Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| topic_facet |
Gryphaeids Shell beds Storm deposits Upper jurassic accumulation rate bioturbation bivalve bottom current fossil record geological record hydraulic conductivity Jurassic Oxfordian paleobiogeography reworking sedimentology shell bed taphonomy vertical distribution wave energy Argentina Bardas Blancas Mendoza Gryphaea Gryphaeidae |
| description |
Griphaeid-dominated fossil concentrations of La Manga Formation are characterized on the basis of taphonomic, sedimentologic, stratigraphic and palaeoecologic criteria. These concentrations are present in the basal deposits (Unit 1) of three outcrops in the locality of Bardas Blancas. Their attributes allow distinguishing seven different fossil accumulations: A) Channelized fossil concentrations of Gryphaea sp.; B) Shell beds of Gryphaea sp. highly reworked; C) Shell beds of Gryphaea sp. moderately reworked; D) Accumulations of Gryphaea sp. with biomicrite to biopelmicrite matrix; E) Shell detritus; F) Accumulations produced by bottom currents; and G) Accumulations found in clumps. Accumulations A-C were deposited by high energy processes (storm waves and currents) in the upper middle ramp. Accumulations D and E were produced by high energy processes (storm waves and currents) but the final depositions were produced out of suspension in low energy environments, in lower middle ramp settings. Accumulations F were generated by weak bottom currents, meanwhile accumulations G correspond to gryphaeids associations reworked by bioturbators or by hydraulic processes after variable periods of permanence in sediment/water interface. Both are interpreted as lower middle or outer ramp. This interpretation suggests that these deposits that in previous works were interpreted as outer ramp settings, characterize middle and outer ramp settings. The vertical distribution of fossil concentrations from upper middle ramp to lower middle and outer ramp settings evidences a continuously growing accommodation space and allows to interpret the Unit 1 as part of a transgressive systems tract. |
| author |
Bressan, Graciela Susana Palma, Ricardo Manuel |
| author_facet |
Bressan, Graciela Susana Palma, Ricardo Manuel |
| author_sort |
Bressan, Graciela Susana |
| title |
Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| title_short |
Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| title_full |
Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| title_fullStr |
Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| title_full_unstemmed |
Taphonomic analysis of fossil concentrations from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza Province, Argentina |
| title_sort |
taphonomic analysis of fossil concentrations from la manga formation (oxfordian), neuquén basin, mendoza province, argentina |
| publishDate |
2010 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_16986180_v36_n1_p55_Bressan http://hdl.handle.net/20.500.12110/paper_16986180_v36_n1_p55_Bressan |
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AT bressangracielasusana taphonomicanalysisoffossilconcentrationsfromlamangaformationoxfordianneuquenbasinmendozaprovinceargentina AT palmaricardomanuel taphonomicanalysisoffossilconcentrationsfromlamangaformationoxfordianneuquenbasinmendozaprovinceargentina |
| _version_ |
1768542858753605632 |