Brazilian Journal of Geology 

About: Brazilian Journal of Geology is an academic journal published by Sociedade Brasileira de Geologia. The journal publishes majorly in the area(s): Zircon & Archean. It has an ISSN identifier of 2317-4692. It is also open access. Over the lifetime, 1903 publications have been published receiving 22731 citations. The journal is also known as: Revista Brasileira de Geociências.

O Cráton do São Francisco

Abstract: This paper is an attempt to justify the original concept of the Sao Francisco Craton and to define its limits. This Craton covered almost the entire State of Bahia and parts of the near Minas Gerais, Goias, Pernambuco and Sergipe States during the Brasiliano Cycle. The authol characterizes the Aracuai folded belt whose structures correspond to the Macaubas Group and are disposed on the southern and southeastern borders of the Craton. The nature of the limits of the Craton with the adjacent folded belts is discussed. A proposal to establish these limits along evident marginal faults with .justified inferences between them is submitted.

Origem e evolução da Serra do Mar

Abstract: The origin of the subparallel mountain systems which compose the coastal Serra do Mar and the inland Serra da Mantiqueira is related to the Upper Cretaceous. These features - distributed along a quite singular continental atlantic border - nave a complex evolution arising controversial questions. The answers to these problems are mainly dependentto the dating of the Japi erosional surface and other younger ones, a study still faced by the small amount of detailed-scale surveys. The scarp domains covered by dense vegetation often impose difficult trail access. Nevertheless, the present knowledge stage allows us to admit that during Tertiary the evolution of the local relief has affected into a considerable extent the synchronic oceanic phase sediments of the Santos Basin. There is a lot of evidence and proofs that the Serra do Mar has been developed from a very different geographical position as compared to the existing one. The hypothesis supported by the present authors is a long-term scarp retreat from southeast to northwest due to erosional processes approximately starting at the Santos fault line in the present continental platform.

The Brasiliano collage in South America: a review

Abstract: Analysis of recent geological and geochronological data from the basement of the South American platform indicates that the Brasiliano orogenic collage took place in four distinct pulses: a) Early Cryogenian (ca. 800 - 740Ma); b) Late Cryogenian-Early Ediacaran (ca. 660 - 610 Ma); c) Early-Middle Ediacaran (c. 590 - 560 Ma); and d) Late Cambrian (520 - 500 Ma). The first three pulses are well represented in most Neoproterozoic structural provinces in West Gondwana. The youngest orogenic phase/pulse, however, is only seen in Argentina (Pampean Orogeny) and Brazil, in eastern Rio de Janeiro State (Buzios Orogeny). The period between ca. 750 and 500 Ma is comparable to that reported for the amalgamation of various continental fragments in East (Arabian-Nubian, Mozambique, Kuunga) and North Gondwana (Cadomian). However, important differences in the nature and ages of events are recognized, which can be expected in view of the magnitude of Gondwana agglutination and the diversity of paleogeographic and tectonic scenarios. West Gondwana shows an interesting peculiarity: lithologically and tectonically diversified Tonian terranes underlie Brasiliano orogenic buildups. They were strongly reworked during most of the orogenic pulses. The Tonian terranes (1000 - 900 Ma) and their relation with Rodinia or with the processes of Gondwana fusion remains an open question. Indications of their presence in East Gondwana are still poorly documented.

Revisão estratigráfica da parte oriental da Bacia Bauru (Neocretaceo)

Abstract: This paper deals with the stratigraphy of the Bauru Basin based on regional investigation. The Bauru Basin was formed in the Late Cretaceous (Coniacian- Maastrichtian) as a result of subsidence of the central-southern part of the South-American Platform.This inner continental basin spreads over an area of approximately 370,000 km2 and is filled by a sandy sequence with maximum thickness of 300 meters at present. Its substratum is constituted by volcanic rocks (mainly basalts) of the Serra Geral Formation (1K) from which it is separated by a regional erosive surface. The studied area, with about 180,000 km , corresponds to the eastern part of the basin (west of Sao Paulo, southwest of Minas Gerais, northwest of Parana), and is located between the coordinates 18°S to 25° S and 47° W to 54° W. According to the distribution and interrelations of the units a stratigraphic revision was proposed for the basin. The Upper Cretaceous sequence is now divided in two groups, partially contemporaneous: Caiua Group (Rio Parana, Goio Ere and Santo Anastacio formations) and Bauru Group (Uberaba, Vale do Rio do Peixe, Aracatuba, Sao Jose do Rio Preto, Presidente Prudente, and Marilia formations, including the Taiuva analcimites).

Orogenias paleozóicas no domínio sul-ocidental do gondwana e os ciclos de subsidência da bacia do paraná

Abstract: The geological development of the Parana Basin was influenced by the geodynamics of southwestern Gondwana, a domain continuously affected during almost all the Phanerozoic eon by compressional stresses derived from a persistently active convergent motion between the continental block and the oceanic lithosphere of Panthalassa. The Parana Basin was supported by a cratonic basement since its inception, but had in its neighbourhood evolving collisional belts fringed by foreland basins. Some areas were selected representing the history of subsidence along the foreland domain of southwestern Gondwana during Paleozoic times. The subsidence analysis showed that such foreland basins experienced cycles of accelerated subsidence that coincide in time with the major orogenic phases, that were related to the docking of terranes along the margin of the continent. The computation of average subsidence rates revealed the main subsidence cycles for the region as a whole. Subsidence and sediment accumulation in the Parana Basin started during Middle to Late Ordovician times when the Precordillera terrane collided against Gondwana and produced the different contractional phases of the Ocloyic Orogeny. The intraplate response to the compressional stresses related to this orogenic cycle was transtensional reactivation of weakness zones, providing the initial subsidence for the Parana Basin. Repeatedly during the geologic history of the Parana Basin orogenic cycles left their signature as periods of accelerated subsidence. Subsidence plots revealed that Early Devonian times, when the stresses generated by the Precordilleran Orogeny affected Gondwana, and Late Permian times, under the yoke of the Sanrafaelic Orogeny, were periods when intracratonic subsidence rates increased remarkably. An integrated analysis of the sedimentary record of the Parana Basin, considering eustatic variations of the sea level and subsidence cycles of southwestern Gondwana led to the conclusion that the stratigraphic cyclicity observed in the Parand Basin was ultimately influenced by its subsidence history. The presumed global correlation peaks shown in Vail's curve, of Late Silurian, Early Carboniferous and Early Permian ages, are not present in the Parana Basin. Instead, local maximum flooding levels developed in each one of the second order transgressive cycles, during Early Silurian, Early Devonian and Late Permian times, defining the particular subsidence history of this interior basin as an intraplate response to geodynamic processes affecting southwestern Gondwana margin.