Maria da Glória Motta Garcia

Urban Geotourism and the Old Centre of São Paulo City, Brazil

The use of geotouristic trails will be an efficient means of publicising geosciences. The proposal here is a trail in the old centre of São Paulo City, Brazil, describing the main types of stones that have ornamented buildings since the nineteenth century when São Paulo ceased to be a city of taipa (rammed earth) buildings and became the masonry city of the republic. Itaquera Granite is one of the most important stones in the ornamentation of the floors and facades in this new phase of construction in the city of São Paulo. Later, other types of stones were used, such as the Mauá, Ubatuba, Itupeva and Piracaia granites, as well as imported stones, such as travertine and lioz limestone. There is also a discussion of the influence of geomorphology in the establishment of the former urban core, with the location of the so-called Historic Triangle at higher topographic levels. This paper discusses the history and evolution of São Paulo City and its relation to the local geology.

Provenance and tectonic setting of neoproterozoic supracrustal rocks from the Ceará Central Domain, Borborema Province (NE Brazil): constraints from geochemistry and detrital zircon ages

Major- and trace-element and U–Pb analyses of detrital zircons were performed on metavolcano sedimentary sequences and igneous rocks from the Ceará Central Domain (CCD) in the Borborema Province of northeastern Brazil. No significant geochemical differences were found between these rocks, which were possibly initially deposited as parts of a very large metavolcano-sedimentary sequence. Weathering in the source area was moderate, and the sediments were deposited as both sands and clays. The sources of the sediments were likely mixtures of felsic and intermediate rocks deposited predominantly in an active-margin setting with minor contributions of both continental arc and passive margin components. Three main source ages were identified: Palaeoproterozoic (~2.2 Ga), for which potential sources include the Palaeoproterozoic Madalena-Algodões Suite; early Neoproterozoic (~850 Ma), related to felsic volcanic magmatism due to continental rifting, initial phases of the Santa Quitéria Magmatic Arc, or magmatic arc systems on the margins of the Palaeoproterozoic crust; and late Neoproterozoic (~650 Ma), associated with extensive granite generation and migmatization events accompanying Santa Quitéria Arc activity. Deposition of the CCD volcanosedimentary rocks occurred shortly before regional, collision-type metamorphism accompanying the amalgamation of the São Francisco-Congo Cratons (~ 620–630 Ma).Major- and trace-element and U–Pb analyses of detrital zircons were performed on metavolcano sedimentary sequences and igneous rocks from the Ceara Central Domain (CCD) in the Borborema Province of northeastern Brazil. No significant geochemical differences were found between these rocks, which were possibly initially deposited as parts of a very large metavolcano-sedimentary sequence. Weathering in the source area was moderate, and the sediments were deposited as both sands and clays. The sources of the sediments were likely mixtures of felsic and intermediate rocks deposited predominantly in an active-margin setting with minor contributions of both continental arc and passive margin components. Three main source ages were identified: Palaeoproterozoic (~2.2 Ga), for which potential sources include the Palaeoproterozoic Madalena-Algodoes Suite; early Neoproterozoic (~850 Ma), related to felsic volcanic magmatism due to continental rifting, initial phases of the Santa Quiteria Magmatic Arc, or magmatic ar...

The inventory of geological heritage of the state of São Paulo, Brazil: Methodological basis, results and perspectives

An inventory of geological sites based on solid and clear criteria is a first step for any geoconservation strategy. This paper describes the method used in the geoheritage inventory of the State of São Paulo, Brazil, and presents its main results. This inventory developed by the geoscientific community aimed to identify geosites with scientific value in the whole state, using a systematic approach. All 142 geosites representative of 11 geological frameworks were characterised and quantitatively evaluated according to their scientific value and risk of degradation, in order to establish priorities for their future management. An online database of the inventory is under construction, which will be available to be easily consulted and updated by the geoscientific community. All data were made available to the State Geological Institute as the backbone for the implementation of a future state geoconservation strategy.

Oxygen isotope composition and geothermometry of granulite to greenschist facies metamorphic rocks: a study from the Neoproterozoic collision-related nappe system, south of Sao Francisco Craton, SE Brazil

Abstract Oxygen isotope studies were carried out across units of a Neoproterozoic nappe system, south of Sao Francisco Craton. A temperature decrease toward the base of the system is found, consistent with a previously recognized inverted metamorphic pattern. The tectonic contact of the basal unit and the reworked southern Sao Francisco craton show a steep temperature gradient, suggesting that low temperature thrusting acted as the dominant tectonic process. The contrasts between the δ18O values of the Tres Pontas-Varginha and Carmo da Cachoeira nappes and the differences among the samples and minerals are consistent with the preservation of sedimentary isotopic composition during metamorphism. The small differences in the δ18O values between the undeformed and the deformed calc-silicate samples (∼1.6‰) suggest that the δ18O value of mylonitization fluids was close to that which equilibrated with the metamorphic assemblage. The distinct δ18O values of metapelitic and calc-silicate samples and the great temperature difference from one type to the other indicate that no large-scale fluid interaction processes occurred during metamorphism. Oxygen isotopic estimations of both Tres Pontas-Varginha undeformed rocks and Carmo da Cachoeira unaltered equivalents indicate δ18O values of up to 18‰. Comparison between these values and those from the ‘basement’ orthogneisses (8.3–8.5‰) indicates the latter are not sources for the metapelites.

Aspectos geológicos, históricos e estado de conservação das fortificações da Baixada Santista, litoral paulista

Military fortifications were built at strategic locations in Brazil for the purpose of defending the territory. Currently, many of them are protected by law as representatives of the colonial period and are used for tourist purposes. The aim of this study is to identify the types of stones used in the construction of military fortifications built between sixteenth and twentieth centuries on the coast of Sao Paulo State within the municipalities of Bertioga, Guaruja and Praia Grande and infer the probable origin of these stones. Identification of the type of material used in these constructions allows a better understanding of the history, culture, technical and geodiversity at the time of their construction. The evaluation of their condition and current use is intended to support actions to which the fortifications may be submitted in order to preserve and maintain the cultural heritage in stone. The fortifications were constructed mainly with granites and gneisses that crop out in the region. Although some of them are listed by the National Institute for Historical and Artistic Heritage (IPHAN) and are the focus of tourism, some of them are deteriorated and require repair in order to conserve and preserve these fortifications, which represent a period in the defense of the State of Sao Paulo.

Gondwana Geodiversity and Geological Heritage: Examples from the North Coast of São Paulo State, Brazil

The North Coast of Sao Paulo is marked by a geologic history related to the Western Gondwana supercontinent, amalgamated during the Brasiliano Cycle in the Neoproterozoic-Cambrian, and fragmented in the Jurassic-Cretaceous. Reactivations during the Cenozoic were also responsible for the current configuration of the Serra do Mar Mountain Range and the coastline. Moreover, the region holds the largest preserved area of Atlantic Forest in Brazil, which increases its importance as a protected zone. In addition to physical aspects records of history dating back 2500 years, as well as numerous buildings from the colonial period that tell a story of challenges between native peoples and conquerors occurred in the area. Together these features led to a rich culture, characterised by a mixture of customs of diverse traditional populations and that outlined the current cultural values. The aim of this work is to associate the main geological events that occurred during the Neoproterozoic-Paleogen, including merging and fragmentation of Gondwanaland and associated processes, to Geodiversity values. These actions are intended to include sites of recognised geoscientific value into local geotourism programs, including support for sustainability, preservation of history and traditional culture, integration of coastal population, and income generation.

Inventário e avaliação quantitativa do patrimônio geológico de Bertioga (SP, Brasil)

Bertioga is located on the coast of Sao Paulo State and is well known for outstanding geodiversity. This work aims to discuss the methodological approach used for the inventory and for the quantitative assessment of the Bertioga’s geological heritage. The selection of the sites the inventory was carried out based on: (i) literature review; (ii) interviews with researchers who conduct geoscience research in the region; (iii) analysis of geological and structural maps and satellite images, for identified potential areas; (iv) field work; and (v) selection and description of the sites. The inventory include eight geosites, three geodiversity sites for educational use and one for touristic use, which are representative of the geological history of the municipality. The quantification of geological heritage was performed based on existing methods and the relevance of the sites was obtained and is intended to guide the choice of future geoconservation strategies. In accordance with the results, only the geosite River Capture of Guaratuba River obtained the same ranking in different methods. Based on the results, we compared the ranking obtained between the methods for available which parameters responsible for the different results. There are thirteen environmental protection areas within the municipality’s limits, the priority is conservation of biodiversity, and actually, there is no proposal for the conservation of the geodiversity. Through the results of evaluation of degradation risk, we conclude although some sites are within the protected areas, some have moderate risk of degradation and need public policies for their management.

Identificação de sítios geológicos para gestão prioritária: propostas para a geoconservação no Domínio Ceará Central, nordeste do Brasil

A avaliacao quantitativa de valoracao do patrimonio geologico tem se demonstrado uma relevante ferramenta para delinear estrategias de geoconservacao, sobretudo em areas extensas e com escassez de recursos. A area selecionada para este estudo corresponde a uma regiao socioeconomicamente vulneravel no semiarido do estado do Ceara, nordeste do Brasil, e contempla um conjunto de 52 sitios geologicos representativos da evolucao geodinâmica do Dominio Ceara Central. Com o intuito de delinear estrategias de geoconservacao pertinentes a realidade local, este trabalho teve por objetivo identificar quais os geossitios prioritarios no plano de gestao. Para tanto, foi utilizado o metodo de avaliacao quantitativa integrado na plataforma GEOSSIT do Servico Geologico do Brasil, tendo sido avaliado o valor cientifico, o risco de degradacao, o potencial uso educativo e turistico e as prioridades de protecao. Os resultados indicaram que os geossitios inventariados possuem alto valor cientifico, que existe predominância de geossitios com risco moderado de degradacao e predominio de valores medianos para o potencial uso educativo e turistico. Tres listas de sitios prioritarios foram definidas, considerando apenas os locais com alto valor cientifico e potencial uso relevante. No final, foi possivel identificar e justificar quatro territorios estrategicos para a geoconservacao na porcao centro-norte do Dominio Ceara Central.

Conservation of geosites as a tool to protect geoheritage: the inventory of Ceará Central Domain, Borborema Province - NE/Brazil

The Ceará Central Domain, in the northern Borborema Province/NE Brazil, encompasses important geological records (geosites) which allow understanding a relevant period of the Earths evolution, mainly associated to Neoproterozoic Brazilian/Pan-African Cycle and West Gondwana amalgamation, besides Neoarchean to Ordovician records. The presented geoheritage inventory aims to characterise the geosites with scientific relevance of Ceará Central Domain. By applying a method for large areas, the final selection resulted in eight geological frameworks represented by 52 geosites documented in a single database. This is the first step for a geoconservation strategy based on systematic inventories, statutory protection, geoethical behaviour and awareness about scientific, educational and/or cultural relevance of geosites.