Rasto Formation Research Articles

Caracterização dos argilominerais usados em matéria-prima cerâmica, da formação Rio do Rasto, Bacia do Paraná, no município de Turvo, SC

No sudeste de Santa Catarina existem inúmeras minas de exploração de argilas destinadas à indústria cerâmica da região. Para o conhecimento desta matéria prima foi realizada a caracterização em detalhe de uma frente de lavra em atividade. A exploração é realizada em terrenos sedimentares da Formação Rio do Rasto (Permiano Superior) na Bacia do Paraná que afloram como morros testemunho. Foram coletadas quatorze amostras representativas dos níveis desta mina composta de argilitos com intercalação de siltitos de pequena espessura. As amostras foram analisadas por difratometria de raios X pelo método do pó na rocha total e na fração < 4 µm. A composição química foi determinada por fluorescência de raios X. Foram realizadas observações ao microscópio eletrônico de varredura (elétrons secundários) de fragmentos das amostras e microanálises por microssonda eletrônica de lâminas delgadas. Os resultados mostraram uma grande variação vertical da mineralogia, tendo sido identificados três níveis diferentes. Até 2,00 m há predomínio de esmectita. Entre 2,00 m e 5,50 m a esmectita é o principal argilomineral, mas com quantidade significativa de ilita/mica, e acima de 5,50 m há grande aumento do feldspato potássico e mica detrítica. Estudos de detalhe por difratometria de raios X (determinação do parâmetro b) e microanálises WDS por microssonda eletrônica permitiram identificar como montmorilonita a espécie argilomineral do grupo das esmectitas.

30 million years of Permian volcanism recorded in the Choiyoi igneous province (W Argentina) and their source for younger ash fall deposits in the Paraná Basin: SHRIMP U–Pb zircon geochronology evidence

We present four SHRIMP U–Pb zircon ages for the Choiyoi igneous province from the San Rafael Block, central–western Argentina. Dated samples come from the Yacimiento Los Reyunos Formation (281.4 ± 2.5 Ma) of the Cochicó Group (Lower Choiyoi section: andesitic breccias, dacitic to rhyolitic ignimbrites and continental conglomerates), Agua de los Burros Formation (264.8 ± 2.3 Ma and 264.5 ± 3.0 Ma) and Cerro Carrizalito Formation (251.9 ± 2.7 Ma Upper Choiyoi section: rhyolitic ignimbrites and pyroclastic flows) spanning the entire Permian succession of the Choiyoi igneous province. A single zircon from the El Imperial Formation, that is overlain unconformably by the Choiyoi succession, yielded an early Permian age (297.2 ± 5.3 Ma), while the main detrital zircon population indicated an Ordovician age (453.7 ± 8.1 Ma). The new data establishes a more precise Permian age (Artinskian–Lopingian) for the section studied spanning 30 Ma of volcanic activity. Volcanological observations for the Choiyoi succession support the occurrence of explosive eruptions of plinian to ultraplinian magnitudes, capable of injecting enormous volumes of tephra in the troposphere–stratosphere. The new SHRIMP ages indicate contemporaneity between the Choyoi succession and the upper part of the Paraná Basin late Paleozoic section, from the Irati up to the Rio do Rasto formations, encompassing about 24 Ma. Geochemical data show a general congruence in compositional and tectonic settings between the volcanics and Paraná Basin Permian ash fall derived layers of bentonites. Thickness and granulometry of ash fall layers broadly fit into the depletion curve versus distance from the remote source vent of ultraplinian eruptions. Thus, we consider that the Choiyoi igneous province was the source of ash fall deposits in the upper Permian section of the Paraná Basin. Data presented here allow a more consistent correlation between tectono-volcanic Permian events along the paleo-Pacific margin of southwestern Gondwana and the geological evolution of neighboring Paleozoic foreland basins in South America and Africa.

A new permian bivalve (megadesmidae, plesiocyprinellinae) from the serrinha member, Rio do Rasto Formation, Paraná Basin, Brazil

During a recent inspection in the Paleontological Collection of the Institute of Geosciences, University of Sao Paulo, we have identified some specimens of undescribed mollusk bivalves. These called our attention for the following reasons: a) all specimens are internal molds of conjugated and closed articulated valves, some of them presenting fragments of silicified shells; b) all internal molds have similar general shape and internal characters, representing specimens of the same taxon; c) the internal molds and silicified valves are well preserved, including fragile structures, which are hardly preserved, such as the internal mold of the external ligament and muscle scars; d) and equally important, according to the labels of all specimens, they were collected from rocks of the Passa Dois Group (Permian), Serrinha Member of the Rio do Rasto Formation. Although who collected the shells and the precise geographic location of the specimens are still unknown, the detailed study of these fossils brings us to the conclusion that they are morphologically distinct from any heretofore published genus of the endemic fauna of bivalves from Passa Dois Group. Based in its general shape, hinge structure and muscles scars, the new form can be classified under the Family Megadesmidae Vokes, 1967, the most diverse group of Permian bivalves of the Parana Basin. The specimens are referred as Beurlenella elongatella new gen. and sp. The shell shape and taphonomy indicate that this bivalve was a shallow, rapid, active burrower, suspension feeder, probably preserved in situ, in event deposits.

Leaiid conchostracans from the uppermost Permian strata of the Paraná Basin, Brazil: Chronostratigraphic and paleobiogeographic implications

Abstract Conchostracan fossils are abundant and relatively diversified in the Rio do Rasto Formation (Passa Dois Group, Parana Basin, southern Brazil), but leaiids (‘ Leaia pruvosti ’ [Reed, F.R.C., 1929. Novos Phyllopodos Fosseis do Brasil. Boletim do Servico Geologico e Mineralogico do Brasil 34, 2–16]) were previously found at only one locality of the formation in the northern Santa Catarina State. New specimens of the Family Leaiidae, collected from two outcrops in central Parana State near the top of the formation, stimulated a revision of related taxa. Both the new and the previously known leaiids are herein assigned to Hemicycloleaia mitchelli [Etheridge Jr., R., 1892. On Leaia mitchelli Etheridge. Proceedings of the Linnean Society of New South Wales 7, 307–310] based on the presence of three carinae and subovate shape. This species was originally recorded in the upper Tatarian (Wuchiapingian, Late Permian) of Sydney Basin, eastern Australia and therefore corroborates the interpretation that the leaiid bearing strata of the Rio do Rasto Formation cannot be younger than Permian. H. mitchelli possibly was one of the most widespread, eurytopic and conservative Late Paleozoic conchostracans of Gondwana (although records from Africa, India and Antarctica must still be confirmed) and it was also found in the Tatarian of Russia. The sudden disappearance of leaiids after their apparent success is consistent with the hypothesis about the biotic crisis around the Permo-Triassic boundary.

Registros Palinológicos Inéditos nas Formações Teresina e Rio do Rasto (Permiano, Grupo Passa Dois, Bacia do Paraná) Implicações Biocronoestratigráficas e Paleoambientais

The Pennsylvanian-Permian interval of the Paraná Basin is relatively well-known on its palynological content. However, little has been published from the Permian Serra Alta, Teresina and lower Rio do Rasto formations (Passa Dois Group). A total of thirty seven core samples were collected along a vertical range of 600 meters of these units in two boreholes in the Congonhinhas Municipality, northeastern Paraná State, South Brazil, but only the Teresina Formation and the lower part of the Serrinha Member of the Rio do Rasto Formation yielded identifiable palynomorphs. Of the thirty recorded species, ten species are registered for the first time in the basin, three are probably new, and five were previously documented at stratigraphic levels below the units of the present study. Assemblages are assigned to the Lueckisporites virkkiae Zone, regarded as Middle Permian (Guadalupian) in age, as suggested by other fossil and radiometric data. According to the relative abundance of some spore species, it is possible to discriminate two intervals: the first characterized by the predominance of Laevigatosporites vulgaris (from the Teresina Formation to the basal Serrinha Member), and the second dominated by Thymospora (in higher stratigraphic levels). The great abundance of fern spores in these assemblages is amazing because lycophyte stems are the best represented macrophytofossils of the Teresina Formation, similarly as glossopterid leaves and sphenophyte stems in the Rio do Rasto Formation. These aspects are discussed in the scope of lithofaciological and other paleontological data.

Correlações Estratigráficas Conflitantes no Limite Permo-Triássico no Sul da Bacia do Paraná: O Contato Entre Duas Seqüências e Implicações na Configuração Espacial do Aqüífero Guarani

The stratigraphic register of the Guarani aquifer system in the Parana basin involves deposits of the Triassic to the Cretaceous. The register in the south region differs from the other areas of the basin, causing confusion in the stratigraphic conception of the Pirambóia Formation. This formation is correlated with paleozoics deposits whose register is only found in the south region of the basin. The correlation that intends for these units has implications in the space configuration and distribution of the aquifer. The space relationships of this record are reinterpreted. The Rio do Rasto Formation, of late Permian age record alluvial plain system, in a progressive semiarid environment, including dune fields; in the southern part of the basin these dune field are extensive and is represented by thick record, covered again by extensive fluvial deposits of the Sanga do Cabral Fm at the PT boundary. The unconformity above records a generalized uplift, associated to the Gondwanides orogeny and to climatic changes, accompanied by progressive supply and sin-sedimentary deformation. Above the unconformity, aeolian and fluvial deposits of the Mesozoic sequence present division organized in 3 blocks: West, Central and East. Three depositional cycles were identified. The first, unconformable over Permian rocks, occurs only in the Central Block, with fluvial and lacustrine deposits filling small rifts (Santa Maria and Caturrita fms). The second cycle extends over the whole basin with fluvial deposits and humid aeolian (formations Guará and Pirambóia); the fluvial and aeolian Guará Fm lies unconformable over Sanga do Cabral Fm in the West Block. In the East Block the aeolian and fluvial unit identified as Pirambóia Fm correlative; it occurs unconformable over the Rio do Rasto Fm, omitting the Sanga do Cabral Fm and the rocks of the first cycle. The third cycle system tract records super arid dune fields of the Botucatu Formation. The Late Permian aeolian facies of the Sanga do Cabral Fm, previously called by some authors as the Pirambóia Fm, doesn't present interfingers and doesn't constitute a hydrostratigraphic unit connected to the Guarani System.

Conchostráceos com linhas de crescimento recurvadas junto à margem dorsal (famílias Palaeolimnadiopseidae e Perilimnadiidae) da formação rio do rasto, Permiano superior, bacia do Paraná, Brasil

Alguns conchostráceos permianos da Formação Rio do Rasto (Bacia do Paraná, Brasil) apresentam um encurvamento bem característico nas linhas de crescimento na região próxima à margem dorsal. Todos os exemplares previamente descritos foram atribuídos a Palaeolimnadiopsis subalata (Reed) Raymond. Porém, uma reanálise deste material fóssil e de exemplares adicionais demonstrou que nem todos os espécimes podem ser incluídos em um mesmo táxon, nem em uma mesma família (Palaeolimnadiopseidae). De acordo com a forma da carapaça e tamanho do umbo, estes exemplares são aqui referidos a três espécies. As carapaças de formato subelíptico, com umbo pequeno e em posição subanterior são mantidas em Palaeolimnadiopsis subalata (Reed, 1929) Raymond, 1946. As carapaças subcirculares com umbo pequeno em posição subcentral correspondem a Palaeolimnadiopsis riorastensis sp. nov. As valvas de formato elíptico com umbo grande e anterior são atribuídas à Falsisca brasiliensis sp. nov., da Família Perilimnadiidae. O gênero Palaeolimnadiopsis tem uma ampla distribuição cronoestratigráfica, porém o gênero Falsisca está restrito ao Permiano superior - Triássico inferior, da Europa e da Ásia. Este intervalo está de acordo com a provável idade permiana superior dos estratos onde foram encontrados estes fósseis na Formação Rio do Rasto. O gênero Falsisca é aqui referido pela primeira vez ao registro fóssil do Gondwana.

Evolução sedimentar da Formação Rio do Rasto (Permo-Triássico da Bacia do Paraná) na porção centro sul do estado de Santa Catarina, Brasil

Between the Late Carboniferous and the Early Triassic, the south portion of the Gondwana Supercontinent witnessed the development of intracratonic basins related with the coeval Sanrafaelic Orogeny. The continuous subsidence and consequent generation accommodation space resulted in the formation of a large confined water body and the accumulation of a transgressive-regressive sequence between the Late Permian and the Early Triassic. The progradational nature of the upper portion of this sequence, represented by de Rio do Rasto e Piramboia formations, culminated with the complete filling of the water body. In the south-eastern portion of Santa Catarina State (Southern Brazil), the Rio do Rasto Formation overlies the Teresina formation and is overlain by the Piramboia formation, both contacts being characterized by lithological transition. The lower portion of the Rio do Rasto Formation is characterized by architectural elements deposited in offshore environments subject to storm action. A marked change of the color of the pelitic facies, from gray to red and purple occurs at the top of the unit. At this stratigraphic level, there is also a predominance of deltaic and eolian architectural elements. The intercalation of nearshore and offshore architectural elements can be explained by the strong auto cyclic character expected in deltaic depositional systems and by the variation of relative rates of base-level rise. The occurrence of eolian architectural elements interbedded with subaquatically deposited sediments on the second third of the unit can be considered an evidence of continentalization to the top, materialized as the transition to the Piramboia desert system.

Pareiasaurids from the Rio do Rasto Formation, Southern Brazil: biostratigraphic implications for Permian faunas of the Paraná Basin

Pareiasaurids from the Rio do Rasto Formation, Southern Brazil: biostratigraphic implications for Permian faunas of the Paraná Basin

A Temnospondyl amphibian from the Rio do Rasto Formation, Upper Permian of southern Brazil

A partially preserved lower jaw constitutes the holotype of Bageherpeton longignathus n. g., n. sp., a probable archegosaurid amphibian, which is here assigned to the Platyoposaurinae. The material was collected in the beds of the Rio do Rasto Formation outcropping in Rio Grande do Sul State, southern Brazil. This is the second archegosaurid described for the Permian of Brazil. Prionosuchus plummeri Price 1948, from the Pedra do Fogo Formation in the Parnaiba Basin (northeastern Brazil), is the first. The new taxon differs from other platyoposaurs by the presence of an extremely elongated precoronoid that participates in the mandibular symphysis.

Fácies, Associação de Fácies e Modelo Deposicional dos Arenitos Eólios da Formação Botucatu (Cretáceo Inferior) na Região Sul de Santa Catarina

Investigations of eolian deposits of Botucatu Formation situated at the southern portion of Santa Catarina State allowed the detailed facies characterization of the unit. In this area, the Botucatu Formation is thicker than adjacent areas, with packages that vary between 80 and 200 meters thick. The lower contact is an unconformity that removed deposits of the Rio do Rasto Formation (Permian). The upper contact is concordant with the basalts of the Serra Geral Formation. It is possible to individualize two litofacies: fine to coarse-grained sandstone with planar large scale cross stratification (ACGP) and fine to medium-grained sandstone with concave up medium scale cross stratification (ACMP). These litofacies compose only one facies association that consists of ACGP facies sets and locally by ACMP facies grouped sets. These deposits can be interpreted as resulting of simple crescentic dunes migration with straight to slightly sinuous crest line that locally develops secondary crescentic dunes in frontal face. The absence of wet interdune deposits led to the interpretation that the Botucatu Formation is the record of a dry eolian system. The thick accumulation of eolian dunes and wind pattern inflection along a preferential direction allowed to infer that the analyzed area was in the domain of a topographically depressed region, controlled by NW-SE faulting system related to the initial break up of the Gondwanaland.

The first record of dinocephalians in South America: Late Permian (Rio do Rasto Formation) of the Paraná Basin, Brazil

The first record of dinocephalians in South America: Late Permian (Rio do Rasto Formation) of the Paraná Basin, Brazil

Permian reptilian fauna from the Kundaram Formation, Pranhita-Godavari Valley, India

The Kundaram Formation of the Pranhita-Godavari Valley yields the only Permian reptilian fauna in India. It is composed essentially of a dicynodont assemblage and includes Endothiodon, Cistecephalus, Pristerodon, Oudenodon and Emydops-like forms. The only non-dicynodont member is a captorhinid reptile. These taxa allow the correlation of the Kundaram Formation with the Tropidostoma and/or Cistecephalus Assemblage Zones of the Beaufort Group of South Africa, the basal beds of Madumabisa Mudstones of Zambia, the Ruhuhu and lower part of the Kawinga Formation of Tanzania and the Morro Pelado member of the Rio do Rasto Formation of Brazil, indicating a Late Permian (Tatarian) age. The Kundaram fauna helps in fixing the upper age of the coal-bearing Damuda Group more precisely at Tatarian. The distribution of the Late Permian dicynodonts in the now widely separated geographic areas suggests the close proximity of the continents and a lack of endemism or provinciality.

SUCESSÃO DE FÁCIES NA CAMADA PORANGABA, GRUPO PASSA DOIS, ESTADO DE SÃO PAULO

Much more than a simple contact between lithostratigraphic units, the surface that separates the Permian Passa Dois and Mesozoic Sao Bento groups is an important sequence boundary in of the Parana Basin record, when the old marine sequence was overlain by the triassic continental sequence. The Permian and partially Triassic marine deposition were substituted by aeolian continental deposition just after the final marine regression. The Porangaba Bed, stratigraphically situated in the upper part of Passa Dois Group, represents the final deposition of this retreating epicontinental permian-triassic sea. This bed is composed by breccias, mudrocks, sandstones and calcilutites deposited in tidal flats at the margin of this epicontinental sea, in a site closely to the coastal dunes of the Piramboia Formation. The Porange Bed facies sequence constancy described in outcrops and in 14 well-drillings of PETROBRAS, allows the definition of a Ω sucession, constituted upwards by lithofacies with progressive continental influence. This study demonstrated that major correlation of the rocks of the Porangaba Bed with is with rocks of the underlying units, named Corumbatai, Teresina and Rio do Rasto formations, and not with rocks of the overlying Piramboia Formation.

Conchostráceos da formação Rio do Rasto (bacia do Paraná, permiano superior) no Estado do Paraná e no norte do Estado de Santa Catarina

Conchostracans associated with bivalves, gastropods, ostracodes, fish scales and plant remains (mainly glossopterids and sphenophytes) from 67 outcrops of the Rio do Rasto Formation (Passa Dois Group, Parana Basin, Upper Permian) in Parana and north of Santa Catarina States occur as molds of frequently flattened and not dismembered carapaces (or sometimes isolated valves) in ritmic or massive red, gray and yellowish mudstones, siltstones and fine sandstones. Asmussia regularis and Monoleaia unicostata, previously reported from only a few localities of this formation, in addition to one new genus and species - Paranaleaia supina, are the predominant species and thus have a much broader geographical distribution than previously thought. Other identified species include: Asmussia sp., Cyzicus (Euestheria) sp., C. (Lioestheria) sp., Cyzicus sp., Gabonestheria sp., Palaeolimnadiopsis subalata, cf. Palaeolimnadiopsis sp. and Palaeolimnadia (Palaeolimnadia) sp.. Probable egg capsules were found in association with a carapace of Monoleaia unicostata. The postero-dorsal margin of this species is sometimes preserved as a narrow area with fine longitudinal grooves, possibly related to the articulation of the valves. Two very distinct types of carapace sculpture present in different specimens of this same species may support a separation in two new subspecies: M. unicostata timbcensis and M. unicostata micropolygnata

Schizoneura gondwanensis feistmantel da formação Rio do Rasto (Bacia do Paraná, permiano superior) no estado do Paraná e no norte do estado de Santa Catarina

Specimens of Schizoneura gondwanensis are here described from 13 new outcrops of the Rio do Rasto Formation (Passa Dois Group, Paraná Basin, Upper Permian) in Paraná State and northern Santa Catarina State. This species was previously known in Brazil from only two other locaiities of the same formation. The foliage shoots, preserved as impressions in red and gray mudstones, siltstones and fine sandstones, generally occur as fragments, which may, however, exhibit well-preserved details such as possible structures of the mesophyll and epidermis, only very rarely recognized in other Gondwana specimens of Schizoneura. The fossils also corroborate Feistmantel's observations made in 1880, but overlooked by many later authors, regarding the embracing of the leaf clusters at the nodes, commissural lines, veins, etc. Although the leaf clusters at one outcrop are oblong-oval and not oval-lanceolate as at the other outcrops, ali are tentatively considered as belonging to the same species. Several of the leaf clusters of S. gondwanensis present ruptures along the commissural lines, here interpreted as the result of taphonomic processes or, possibly, environmental factors that affected the living plant. Ontogenetic aspects of Schizoneura and comparisons with Cathaysian representatives of this genus are also discussed. S. gondwanensis thus has a much broader geographical range in Brazil than previously thought and, consequently, can now be considered as one more important element of Rösler's Taphoflora E

Pteridófilas pecopteróides da formação Rio do Rasto no estado do Paraná e da formação estrada nova no estado de São Paulo (Bacia do Paraná, permiano superior)

This paper deals with Pteridophylla and Filicophyta from 23 outcrops of the Rio do Rasto Formation in Paraná State and 2 outcrops of the Estrada Nova Formation in São Paulo State (Passa Dois Group, Paraná Basin, Upper Permian). Equivalent fossils have been described previously from only 3 localities of these same stratigraphic units. The fossils occur as impressions of fragmented fronds and pinnae in red, gray and yellowish mudstones, siltstones and fine sandstones. All the better preserve d pecopterids correspond to new species: Pecopteris taguaiensis, P. dolianitii, P. esperancensis, P. bracatingaensis and P. cadeadensis. Other described specimens are considered as Pecopteris sp.1, P. sp.2, P. sp.3, ?Dizeugotheca bortoluzzii Cazzulo-Klepzig and? Dizeugotheca sp

Sphenophyllum paranaensis n. sp. da formação Rio do Rasto (permiano superior) de Dorizon, estado do Paraná

This paper describes a new species of Sphenophyllum (S. paranaensis n. sp.) from the Rio do Rasto Formation, Serrinha Facies, cropping out along the Dorizon-Paulo Frontin road (State of Paraná, Brazil), 1.5 km south of the main church of Dorizon. The new species is based on isolated leaves, verticils and articulated stems. A few lascinated leaves which occur dispersed at the same outcrop may be interpreted as a polymorphic variation of the new species, but until further data become available they are here called Sphenovhyllum cf. S. thonii, In fact, both forms of this genus from Dorizon are similar to specimens assigned to S. thonii in África but smaller than type material of this species

CONTRIBUIÇÃO À ESTRATIGRAFIA E BIOESTRATIGRAFIA DO GRUPO PASSA DOIS NA SERRA DO CADEADO (NORDESTE DO PARANÁ, BRASIL)

The general stratigraphy of the Passa Dois Group (Permian of the Parana Basin) in the Serrado Cadeado area, northeast of Parana State, Brazil, is discussed. The biostratigraphic distribution of the tetrapods in the area allows the following conclusions: 1) The long-snouted rhinesuchoid amphibians (Australerpeton) are practically restricted to the upper Morro Pelado Member of the Rio do Rasto Formation, with a clearly fluvial sedimentary environment and supporting abundant fish life. 2) Rastosuchus, a short-snouted rhinesuchoid, also occurs in the same member, but it is found in the transitionary levels between Morro Pelado and Serrinha Members as well. Reducing conditions and eventual high salinity might have precluded the presence of Australerpeton in the transitional waters. The authors feel that differential occurrence of the two genera of amphibians could support the recently proposed Serra do Espigao Delta System, to which the Serra do Cadeado area belongs. 3) The presence of Endothiodon and rhinesuchoid amphibians in the Rio do Rasto Formation points suggestively to close affinities with the Cislecephalus Zone paleofauna of the Lower Beaufort Series in Africa. Accordingly, it is here proposed a Tatarian age for this formation.