Bauru Group
The Bauru Group is a lithostratigraphic group from the Upper Cretaceous of southern Brazil. It was deposited in the Bauru Basin, a portion of the Paraná Basin on Lower Cretaceous basalts.
Etymology
The name of the group is derived from the city of Bauru in the Brazilian state of São Paulo.
Stratigraphy
The sediments of the Bauru Group, were deposited from the São Bento Group in Bauru Basin, a sub-section of the larger Paraná Basin with an erosive unconformity concordant to the Lower Cretaceous basalts of the Serra Geral Formation. In the southwest of the Sedimentationsraumes they interlock with the sediments of the Santo Anastácio lineup from the Caiua group or superimpose them. The group consists of the following formations:
- Marília Formation and
- Adamantina lineup.
The basal Adamantina formation itself is constructed from the Araçatuba lineup and the Vale do Rio do Peixe - formation and dovetails in a northeasterly direction with the Uberaba Formation. The Marília Formation consists again of the Subformationen Echaporã, Serra da galga and Ponte Alta and geared towards the south with the São José do Rio Preto Formation, which in turn further south merges into the Presidente Prudente - formation. On the northern edge of the Vale do Rio do Peixe - formation volcanics of the analcimführenden Taiúva lineup are turned on.
The total thickness of the Bauru Group is approximately 300 meters.
Age
No absolute age data are for the Bauru group yet available, on the basis of fossils you can, however, a chalk temporal Upper age from Turonian to Maastrichtian be assigned.
Distribution area
The rocks of the Bauru Group are open in the Brazilian states of Goiás, Mato Grosso do Sul, Minas Gerais and São Paulo.
Deposition conditions
The Bauru Group consists predominantly of terrigenous siliciclastic sedimentary rocks ( sandstones, siltstones, conglomeratic layers ), only sporadically, there are also carbonates. These sediments were deposited under semiarid to arid conditions of meandering rivers ( Wadifazies ), where the annual climate history has been marked by a distinctive rainy season - dry season cycle. Other Faziesbedingungen found in Araçatuba Formation, which represents a dry sometimes falling Paläosumpf, as well as in the dunes of the Vale do Rio do Peixe - formation.
Fossil content
The Bauru Group has a very rich vertebrate fauna. Fish remains ( scales and teeth) make the presence of Fleischflossern, gars, Characins, catfish -like, Knochenzünglerartigen and Barschartigen recognize. Among terrestrial vertebrates, frogs and toads, lizards and turtles are to lead, even some dinosaurs are encountered. Most important, however are undoubtedly the remains of crocodile relatives. Among the birds, a representative of the Enantiornithes was discovered.
Dinosauria - Dinosaurs
- Abelisauridae
- Carcharodontosauridae
- Saltasauridae - Aeolosaurini - vortex remains
- Titanosauridae Adamantisaurus mezzalirai
- Baurutitan britoi
- Maxakalisaurus Topai
- Trigonosaurus pricei
- Uberabatitan ribeiroi
Mesoeucrocodylia - Crocodile Related
- Baurusuchidae Baurusuchus pachecoi
- Baurusuchus salgadoensis
- Baurusuchus sp.
- Stratiotosuchus maxhechti
- Goniopholis paulistanus
- Adamantinasuchus navae
- Itasuchus jesuinoi
- Mariliasuchus amarali
- Sphagesaurus huenei
- Montealtosuchus arrudacamposi
- Peirosaurus Tormini
- Uberabasuchus terrificus
- Brasileosaurus pachecoi
Testudinata - turtles
- Podocnemididae Bauriemis elegans
- Podocnemis elegans
- Roxoquelis wanderlii
Indicative of the Bauru Group is the simultaneous occurrence of faunal elements of the austral Gondwana ( socialization of Abelisauridae with Notosuchidae ) and the boreal Gondwana ( Carcharodontosauridae ). Noteworthy is the absence laurasischer taxa in the upper section of the group.
Among the invertebrates to charophyte, Conchostraca, Mollusca and Ostracoda find.