Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina
Tidal depositional systems are often interpreted as lowstand/transgressive estuarine deposits within sequences that are either wave or river dominated during highstand times. The Middle Jurassic Lajas Formation of the Neuquen Basin, Argentina, comprises 600 m of well-exposed tide-dominated facies de...
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| Format: | Book Chapter |
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Geological Society of London
2005
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| Online Access: | http://hdl.handle.net/20.500.11937/6428 |
| _version_ | 1848745073444913152 |
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| author | Mcllroy, D. Flint, S. Howell, J. Timms, Nicholas Eric |
| author2 | G. D. VEIGA |
| author_facet | G. D. VEIGA Mcllroy, D. Flint, S. Howell, J. Timms, Nicholas Eric |
| author_sort | Mcllroy, D. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Tidal depositional systems are often interpreted as lowstand/transgressive estuarine deposits within sequences that are either wave or river dominated during highstand times. The Middle Jurassic Lajas Formation of the Neuquen Basin, Argentina, comprises 600 m of well-exposed tide-dominated facies deposited within four unconformity bounded sequences, spanning approximately 4.5 Ma. Facies associations include tide dominated deltas, sandy-heterolithic tidal channel fills and extensive progradational tidal-flat successions, which are locally cut by heterolithic tidal channel fills. Despite the narrow bathymetric depositional range and the complex facies variability, flooding surfaces can be defined and mapped along a 48 km-long outcrop belt. These flooding surfaces allow definition of three distinct types of parasequence that exhibit coarsening-upwards, finingupwards and coarsening- to fining-upwards motifs. Sequence boundaries are marked by widespread, but shallow, incision, and the juxtaposition of stacked fluvial/tidal channel fills on a variety of subtidal and intertidal facies. Unconventional grain-size changes at sequence boundaries can occur where basin ward facies shifts are marked by juxtaposition of heterolithic-argillaceous intertidal/supratidal mudflat deposits on subtidal sandflat facies. The maintenance of macrotidal conditions through complete base-level cycles is interpreted as being due to the structural topography inherited from rifting, causing the whole sub-basin to behave as a structurally controlled embayment. |
| first_indexed | 2025-11-14T06:11:34Z |
| format | Book Chapter |
| id | curtin-20.500.11937-6428 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:11:34Z |
| publishDate | 2005 |
| publisher | Geological Society of London |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-64282022-10-11T07:43:48Z Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina Mcllroy, D. Flint, S. Howell, J. Timms, Nicholas Eric G. D. VEIGA L. A. SPALLETTI J. A. HOWELL E. SCHWARZ Argentina tidal depositional systems sedimentology Jurassic Lajas Formation Tidal depositional systems are often interpreted as lowstand/transgressive estuarine deposits within sequences that are either wave or river dominated during highstand times. The Middle Jurassic Lajas Formation of the Neuquen Basin, Argentina, comprises 600 m of well-exposed tide-dominated facies deposited within four unconformity bounded sequences, spanning approximately 4.5 Ma. Facies associations include tide dominated deltas, sandy-heterolithic tidal channel fills and extensive progradational tidal-flat successions, which are locally cut by heterolithic tidal channel fills. Despite the narrow bathymetric depositional range and the complex facies variability, flooding surfaces can be defined and mapped along a 48 km-long outcrop belt. These flooding surfaces allow definition of three distinct types of parasequence that exhibit coarsening-upwards, finingupwards and coarsening- to fining-upwards motifs. Sequence boundaries are marked by widespread, but shallow, incision, and the juxtaposition of stacked fluvial/tidal channel fills on a variety of subtidal and intertidal facies. Unconventional grain-size changes at sequence boundaries can occur where basin ward facies shifts are marked by juxtaposition of heterolithic-argillaceous intertidal/supratidal mudflat deposits on subtidal sandflat facies. The maintenance of macrotidal conditions through complete base-level cycles is interpreted as being due to the structural topography inherited from rifting, causing the whole sub-basin to behave as a structurally controlled embayment. 2005 Book Chapter http://hdl.handle.net/20.500.11937/6428 10.1144/GSL.SP.2005.252.01.05 Geological Society of London restricted |
| spellingShingle | Argentina tidal depositional systems sedimentology Jurassic Lajas Formation Mcllroy, D. Flint, S. Howell, J. Timms, Nicholas Eric Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title | Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title_full | Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title_fullStr | Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title_full_unstemmed | Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title_short | Sedimentology of the tide-dominated Jurassic Lajas Formation, Neuquen Basin, Argentina |
| title_sort | sedimentology of the tide-dominated jurassic lajas formation, neuquen basin, argentina |
| topic | Argentina tidal depositional systems sedimentology Jurassic Lajas Formation |
| url | http://hdl.handle.net/20.500.11937/6428 |