An overview on Callovian-Cenomanian intracratonic basins of Northeast Brazil: onshore stratrigraphic record of the opening of the southern Atlantic
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| Format: | Artículo científico |
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Universitat de Barcelona
2003
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| author | L. M. M. Valença |
| author_facet | L. M. M. Valença |
| contents | An overview on Callovian-Cenomanian intracratonic basins of Northeast Brazil: onshore stratrigraphic record of the opening of the southern Atlantic L. M. M. Valença V. H. Neumann J. M. Mabesoone Ciencias de la Tierra Araripe Tectonic Jurassic Cretaceous Borborema province A number of small Callovian-Albian sedimentary basins occur in the NE-trending Araripe-Potiguar topographiclowlying area. These basins developed in a fairly narrow zone of Precambrian supracrustal rocksfrom the Middle Jurassic onwards, as a consequence of the reactivation of ancient fault lines. The basin formationand subsidence took place during five tectonic stages related with the opening of the SouthernAtlantic Ocean and the split of South America from Africa. The tectonic-sedimentary sequences that fillthese basins record successive evolutionary stages. 1) Proto-rift stage, with minor episodes of ( a) pre-rift(Callovian-Tithonian) with basin formation and deposition of coarse to conglomeratic sandstones in alluvialfan and braided river systems; (b) tectonic quiescence with continuing subsidence, resulting in hundredsof meters of pelites accumulated mainly in lacustrine and foodplain environments (Tithonian-Berriasian).2) Syn-rift stage: (a) tectonic reactivation with erosion and deposition of sandstones in alluvial fanand braided to low-sinuosity river systems; (b) during more quiet periods, accumulation of fine-graineddeposits in lacustrine, palustrine and foodplain environments took place (Berriasian-early Barremian). 3)Erosional stage that would correspond to a transitional proto-oceanic gulf phase in the southern Atlantic anda shift of rifting to the equatorial Atlantic area, causing erosion in the study area (late Barremian-early Aptian).4) Post-rift stage: (a) related to the beginning of drift in the Atlantic Ocean. This stage is characterisedby deposition in the area of shallow lacustrine fine-grained siliciclastics, limestones and gypsum under dryclimate (late Aptian-early Albian); (b) two short marine transgressions affected the area and, as a consequence,shallow marine limestones were deposited (late Aptian and Albian); (c) a marine regression resultedin a return to continental conditions with deposition of coastal and lagoonal limestones, lacustrine rhythmitesand fluvial sandstones (Albian-early Cenomanian?). Some of the lacustrine to fluvial dominatedsequences as well as the marine deposits in these basins include highly fossiliferous units (i.e. Crato andRomualdo Fms. of the Santana Group), with very diverse, exceptionally well preserved fossil assemblages(insects, fishes and reptiles, among others), although they are mainly endemic. 5) Uplift stage: last stage oftectonic calm and slow uplift and erosion (since Cenomanian). On the basis of our proposals further sedimentologicaland paleontological studies have been undertaken, which confirm the existence of an alternativeconnection between the equatorial and southern parts of the Atlantic Ocean in Aptian-Albian times.Moreover, the last break-up stages between Brazil and Africa took place probably in the Campanian. 2003 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50510302 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.3 Vol.1 |
| format | Artículo científico |
| id | redalyc_50510302 |
| institution | Redalyc |
| language | en |
| publishDate | 2003 |
| publisher | Universitat de Barcelona |
| spellingShingle | An overview on Callovian-Cenomanian intracratonic basins of Northeast Brazil: onshore stratrigraphic record of the opening of the southern Atlantic L. M. M. Valença Ciencias de la Tierra Araripe Tectonic Jurassic Cretaceous Borborema province An overview on Callovian-Cenomanian intracratonic basins of Northeast Brazil: onshore stratrigraphic record of the opening of the southern Atlantic L. M. M. Valença V. H. Neumann J. M. Mabesoone Ciencias de la Tierra Araripe Tectonic Jurassic Cretaceous Borborema province A number of small Callovian-Albian sedimentary basins occur in the NE-trending Araripe-Potiguar topographiclowlying area. These basins developed in a fairly narrow zone of Precambrian supracrustal rocksfrom the Middle Jurassic onwards, as a consequence of the reactivation of ancient fault lines. The basin formationand subsidence took place during five tectonic stages related with the opening of the SouthernAtlantic Ocean and the split of South America from Africa. The tectonic-sedimentary sequences that fillthese basins record successive evolutionary stages. 1) Proto-rift stage, with minor episodes of ( a) pre-rift(Callovian-Tithonian) with basin formation and deposition of coarse to conglomeratic sandstones in alluvialfan and braided river systems; (b) tectonic quiescence with continuing subsidence, resulting in hundredsof meters of pelites accumulated mainly in lacustrine and foodplain environments (Tithonian-Berriasian).2) Syn-rift stage: (a) tectonic reactivation with erosion and deposition of sandstones in alluvial fanand braided to low-sinuosity river systems; (b) during more quiet periods, accumulation of fine-graineddeposits in lacustrine, palustrine and foodplain environments took place (Berriasian-early Barremian). 3)Erosional stage that would correspond to a transitional proto-oceanic gulf phase in the southern Atlantic anda shift of rifting to the equatorial Atlantic area, causing erosion in the study area (late Barremian-early Aptian).4) Post-rift stage: (a) related to the beginning of drift in the Atlantic Ocean. This stage is characterisedby deposition in the area of shallow lacustrine fine-grained siliciclastics, limestones and gypsum under dryclimate (late Aptian-early Albian); (b) two short marine transgressions affected the area and, as a consequence,shallow marine limestones were deposited (late Aptian and Albian); (c) a marine regression resultedin a return to continental conditions with deposition of coastal and lagoonal limestones, lacustrine rhythmitesand fluvial sandstones (Albian-early Cenomanian?). Some of the lacustrine to fluvial dominatedsequences as well as the marine deposits in these basins include highly fossiliferous units (i.e. Crato andRomualdo Fms. of the Santana Group), with very diverse, exceptionally well preserved fossil assemblages(insects, fishes and reptiles, among others), although they are mainly endemic. 5) Uplift stage: last stage oftectonic calm and slow uplift and erosion (since Cenomanian). On the basis of our proposals further sedimentologicaland paleontological studies have been undertaken, which confirm the existence of an alternativeconnection between the equatorial and southern parts of the Atlantic Ocean in Aptian-Albian times.Moreover, the last break-up stages between Brazil and Africa took place probably in the Campanian. 2003 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50510302 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.3 Vol.1 |
| title | An overview on Callovian-Cenomanian intracratonic basins of Northeast Brazil: onshore stratrigraphic record of the opening of the southern Atlantic |
| topic | Ciencias de la Tierra Araripe Tectonic Jurassic Cretaceous Borborema province |
| url | https://www.redalyc.org/articulo.oa?id=50510302 |