O novo regime climático do Antropoceno e de Gaia / The new climatic regime of Anthropocene and Gaia / El nuevo régimen climático del Antropoceno y de Gaia

Resumo O artigo discute os conceitos de Antropoceno e de Gaia, apontados por Bruno Latour como categorias para entender o regime climático que estamos vivendo e servir de base teórica para buscar respostas apropriadas para a crise do clima. Os conceitos buscam superar dois pressupostos da racionalidade moderna: a oposição entre natureza e cultura - questionando o princípio de que os humanos são os únicos atores da realidade e introduzindo todos os seres vivos como agentes conformadores do ambiente - e a visão globalizante do planeta Terra, que impede de ver a terra como solo localizado onde acontecem os ciclos biogeoquímicos de transformação da energia que possibilitam a vida. Conclui-se que a reflexão de Latour fornece bases ontológicas para a discussão sobre a mudança climática e pressupostos para a bioética ambiental.

Abstract This article discusses the concepts of Anthropocene and Gaia, raised by Bruno Latour, as categories to understand the climate regime we are experiencing and serve as a theoretical basis to seek appropriate responses to the climate crisis. These concepts seek to overcome two assumptions of modern rationality: the opposition between nature and culture - questioning the principle that humans are the only actors in reality and introducing all living beings as agents shaping the environment - and the globalizing vision of planet Earth that prevents us from seeing it as localized soil where biogeochemical cycles of energy transformation that make life possible take place. It is concluded that Latour's reflection provides ontological bases for the discussion on climate change and assumptions for environmental bioethics.

Resumen Este artículo discute los conceptos de Antropoceno y Gaia, señalados por Bruno Latour como categorías para entender el régimen climático que estamos viviendo y para servir de base teórica para buscar respuestas adecuadas a la crisis climática. Los conceptos buscan superar dos supuestos de la racionalidad moderna: la oposición entre naturaleza y cultura -cuestionando el principio de que los humanos son los únicos actores de la realidad e introduciendo a todos los seres vivos como agentes conformadores del medio ambiente- y la visión globalizante del planeta Tierra, que impide ver la tierra como un suelo localizado en el que tienen lugar los ciclos biogeoquímicos de transformación de la energía que hacen posible la vida. Se concluye que la reflexión de Latour proporciona bases ontológicas para la discusión sobre el cambio climático y supuestos para la bioética ambiental.

Producción científica de la Facultad de Geología y Minas del Instituto Superior Minero Metalúrgico, Cuba, en el período 2003-2015 / Scientific production of the Geology and Mining Faculty of Higher Institute of Mining and Metallurgy, Cuba, in period 2003-2015

RESUMEN El objetivo de la investigación fue describir la producción científica de la Facultad de Geología y Minas del Instituto Superior Minero Metalúrgico de Moa (Cuba), en revistas científicas durante el período 2003-2015. El estudio se desarrolló a través de una estrategia de investigación que combina técnicas exploratorias de búsqueda de información y análisis cuantitativos, mediante el análisis documental y la estadística descriptiva. En este sentido, se analizó la producción científica por años, departamentos docentes, autores y en revistas. Se consultó un total de 224 publicaciones, de ellas 80 en revistas científicas, a partir de la identificación de los focos temáticos de investigación, la información contenida en los curriculum vitae y la consulta a las bases de datos. Los resultados muestran la evolución e impacto de la producción científica en los doce años del período en estudio. Se concluye que, a pesar de que el número de publicaciones registradas en revistas científicas es pequeño, existe una correspondencia entre la producción científica y las líneas de investigación establecidas por la institución. Estos resultados son un reflejo de los intereses y áreas activas de esta Facultad, por lo que los resultados pueden constituir un indicador de su evolución en la institución.

Abstract The purpose of the research was to describe the scientific production of the Geology and Mining School of the Higher Institute of Mining and Metallurgy of Moa (Cuba), in scientific journals during 2003-2015 period. The study is developed by means of a research strategy that combines exploratory techniques of information search and quantitative analyses, through the documentary analysis and descriptive statistics. In this sense analyzed the scientific production for years, teaching departments, authors, and journals. A total of 224 publications were surveyed, of those 80 in scientific journals, through of the identification of the thematic focuses of research, the information given in the curriculum vitae and the databases queries. The results show the evolution and impact of the scientific production in the twelve years of the period under study. It concluded that, despite the number of registered publications in scientific journals is small, there is a matching between the scientific production and the established lines of investigation by the institution. These results reflect the interests and active areas of this Faculty, so the results can be an indicator of his evolution in the institution.

Minério de ferro, geologia econômica e redes de experts entre Wisconsin e Minas Gerais, 1881-1914 / Iron ore, economic geology and networks of experts between Wisconsin and the state of Minas Gerais, 1881-1914

O presente artigo trata da “descoberta” do minério de ferro brasileiro a partir de duas perspectivas. A primeira analisa a crescente ênfase das geociências em sua aplicação prática e em sua globalidade desde a segunda metade do século XIX. Enquanto no Brasil a geologia econômica foi integrada passo a passo às instituições do Estado, no nível global ela viveu momento de triunfo com o 11 o Congresso Geológico Internacional, em 1910. A segunda trata de uma rede social específica com papel decisivo na corrida pelo minério de ferro brasileiro: experts transnacionais movimentandose entre as lógicas do mercado e as da academia. O artigo mostra a importância das negociações locais na incorporação do subsolo mineiro ao espaço global de mineração.

This article deals with the “discovery” of Brazilian iron ore from two perspectives. The first examines the increasing emphasis of the geosciences and their practical application and global reach since the second half of the nineteenth century. While in Brazil economic geology was integrated step by step into state institutions, at the global level it experienced its moment of triumph with the 11th International Geological Congress in 1910. The second deals with a specific social network with a decisive role in the race for Brazilian iron ore: with transnational experts juggling between the logic of the market and that of the academy. The article reveals the importance of local negotiations in the incorporation of the subsoil of Minas Gerais into the global space of mining.

Silva Coutinho: uma trajetória profissional e sua contribuição às coleções geológicas do Museu Nacional / Silva Coutinho: his career and his contributions to the geological collections of the Museu Nacional in Rio de Janeiro

A trajetória profissional de João Martins da Silva Coutinho relaciona-se à história do Museu Nacional (Rio de Janeiro), para cujas coleções, principalmente geológicas, ele contribuiu com informações científicas e remessa de material. No cenário científico brasileiro, participou de grandes comissões de caráter exploratório na segunda metade do século XIX, especialmente na Amazônia e no Nordeste. Coletou e enviou amostras para análise no Museu Nacional, estabelecendo profunda relação com a instituição e seus funcionários. Apresentam-se essas contribuições por meio da análise de documentos e da recuperação das coleções geológicas por ele remetidas e ainda presentes no acervo da instituição.

The career of João Martins da Silva Coutinho is linked to the history of the Museu Nacional in Rio de Janeiro to whose collections (especially geological) he contributed scientific information and material. On the Brazilian scientific stage, Silva Coutinho took part in major exploratory commissions in the latter half of the nineteenth century, mainly in the Amazon and in the Northeast. He collected and sent samples to the Museu Nacional for analysis, establishing deep ties with the institution and its staff. The article presents his contributions through an analysis of these documents and an examination of the geological collections that he sent to the institution and that remain part of its holdings.

Bibliografía sobre investigaciones marinas, oceanográficas, geológicas y atmosféricas en el Parque Nacional Isla del Coco y aguas adyacentes, Pacífico de Costa Rica / Bibliography on marine, oceanographic, geological and atmospheric research at Isla del Coco Nacional Park and adjacent waters, Pacific Costa Rica

Isla del Coco (also known as Cocos Island), Pacific Costa Rica, has been visited and written about since the 16th Century, and since the late 1800’s many expeditions and scientists have carried out research in the Island. Here I compiled publications on marine biological, geological, oceanographic and atmospheric research done at Isla del Coco. A list of 599 scientific papers and chapters were compiled, together with 41 books, reports, Special Issues, theses and web sites, and ten historic books with descriptions of marine animals or environemnets. A mayority of the publications (425 or 66.4%) are related to marine biodiversity topics (species descriptions and lists of species); the most published groups are gastropods (81 papers), decapods (67) and bony fishes (66). There are no publications of several groups of animals that have been observed in the Island, for example free-living flat worms, parasites and nemerteans among others. Other topics with a large number of publications are, biogeography with 65, ecology (61) and geology (48); the most studied ecosystem are coral reefs with 14 papers. More publications are needed on many topics, such as impact of ilegal fishing and climate change on Isla del Coco National Park marine flora and fauna.

Isla del Coco, Pacífico de Costa Rica, ha sido visitada y se ha escrito sobre ella desde el Siglo XVI. Desde finales del Siglo XIX muchas expediciones han desarrollado investigaciones en el Isla. Aquí compilo las publicaciones sobre biología y geología marina, oceanografía física y química, ciencias atmosféricas y algunos temas sociales. Una lista de 599 artículos y capítulos, 41 libros, Suplementos, tesis, informes y un sitio de internet es incluida, y diez libros históricos donde se describen organismos y ambientes marinos de la Isla del Coco. La mayoría de las publicaciones (425 o 66.4%) son sobre biodiversidad marina (descripciones, listas y distribuciones de especies). De los grupos que más publicaciones hay son de los gasterópodos (81 trabajos), decápodos (67) y peces óseos (66). No hay publicaciones de varios grupos de animales que han sido observados en Isla del Coco, por ejemplo, gusanos planos de vida libre, parásitos o nemertinos, entre otros. Temas con muchas publicaciones son: biogeografía con 65, ecología (61) y geología (48); los ecosistemas más estudiados son los arrecifes coralinos con 14 trabajos. Se necesitan más publicaciones en muchos tópicos, tales como el impacto sobre la flora y fauna del Parque Nacional Isla del Coco de la pesca ilegal y el cambio climático.

Marco geológico y tectónico de la Isla del Coco y la región marítima circunvecina, Costa Rica / Geological and geotectonic framework of Isla del Coco and the marine zone off the central Pacific coast of Costa Rica

The Isla del Coco (also known as Cocos Island), in the Eastern Pacific Ocean, has a rough topography, an area of 24km², and is the only sub-aerial topographic height of the summit of a volcano located in the margin of the Cordillera Volcánica del Coco (also known as Cocos Ridge). The Cocos Ridge is a well defined linear bathymetric height, issued from the active volcanism of the Galápagos hotspot during the last 15 million years (Ma); it is the largest geographic feature of Costa Rica, as a volcanic range of 780km long in its territorial seawaters. Isla del Coco is part of a submarine shield volcano of complex evolution, which erupted several times above sea level during the Lower Pleistocene (2.2-1.5Ma). The island and other seamounts are the result from a mantle thermal anomaly that erupted through volcano-tectonic fissures in the oceanic crust. The rocks consist mainly of alkali basaltic lava flows (aa, pahoehoe, blocky lavas) and dikes, minor trachyte lava flows, volcanic domes and dikes, with subordinate pyroclastic and epivolcanic rocks. Colluvial, soils and local littoral deposits such as sand and gravel beaches are also present. The island has a juvenile erosive stadium, but their submarine erosive arcs and platforms (90-110m and 183m depth) are probably the result of the erosion occurred during last two glacial maxima, besides slow subsidence events of the island due the thermal cooling of the volcanic shield and its oceanic crust. The most important current external geodynamic hazards are landslides, tsunamis and rare seismic events, Mw ≤ 5.8 in a 300km radio associated to N-S right lateral strike slip faults. However, the limited seismic data available, and geomorphological alignments, indicates that there is some seismic activity related to local faults oriented N-S, ENE and in a lesser extend NW trend. Seismicity and rainfall have triggered landslides; liquefaction is restricted to Chatham and Wafer bays’ beaches. Moderate historical and prehistorical tsunamis were related to regional seismic events. The relative young age of Isla del Coco makes it an interesting place to study the evolution and migration of species, and their genetic features. More detailed studies related to tephrostratigraphy, neotectonics, marine geomorphology, evolution of seamounts, lava flow morphology, and submarine hydrothermal activity, are still necessary to understand the expression of internal geodynamic processes in this region.

La Isla del Coco es la única isla oceánica y el único afloramiento subaéreo de la Cordillera Volcánica del Coco, el rasgo geográfico y geológico más extenso en aguas territoriales costarricenses. Desde el punto de vista geológico, está conformada por rocas volcánicas, predominantemente coladas de lavas basálticas y traquíticas en menor cantidad, con rocas piroclásticas y epiclásticas subordinadas. Posee suelos, coluvios y depósitos de playas (arenas y cantos) superficiales; su topografía es muy variable pero predomina el relieve quebrado y rugoso. La Isla del Coco es la parte emergida de un volcán submarino de evolución compleja, desarrollado a partir y durante el Pleistoceno Inferior (entre 2.2 y 1.5 millones de años, Ma), producto de una anomalía térmica en el manto a través de varias fisuras, que originaron varios alineamientos de volcanes submarinos. La Isla del Coco se encuentra en un estadio de erosión activo, y sus arcos y plataformas sumergidas (90-110m y 183m) son probablemente el producto de una erosión subaérea durante las dos últimas máximas glaciaciones, combinados quizás con la subsidencia debida al enfriamiento del escudo volcánico y de la corteza oceánica. Al ser la isla geológicamente joven, posee importantes implicaciones para la comprensión de la evolución y el endemismo de su biodiversidad. Las amenazas en la geodinámica principales identificadas son los deslizamientos, los tsunamis y, en menor grado, la sismicidad, poco frecuente y con magnitudes moderadas (≤ 5.8 Mw hasta la fecha) dentro de un radio de alrededor de 300km, predominantemente asociada con fallas dextrales de rumbo N-S. Los pocos datos obtenidos hasta el momento indican que hay un cierto grado de actividad sísmica en los alrededores de la Isla del Coco, relacionados con las fallas locales. Algunos pequeños tsunamis históricos y prehistóricos han afectado a la Isla del Coco y los sismos así como la precipitación pluvial elevada han generado deslizamientos. La licuefacción está restringida a las dos playas arenosas (bahías Chatham y Wafer).

Bibliografía sobre organismos, ambientes y procesos marinos y atmosféricos en Bahía Culebra, Pacífico norte, Guanacaste, Costa Rica (1922-2012) / Bibliography on marine organisms, environments, and oceanographic and atmospheric processes in Bahía Culebra, north Pacific, Costa Rica (1922-2012)

Bibliography on marine organisms, environments, and oceanographic and atmospheric processes in Bahía Culebra, north Pacific, Costa Rica (1922-2012). Bahía Culebra is located on the north Pacific coast of Costa Rica. It is a seasonal upwelling area, rich in marine ecosystems and organisms, and the main tourist development area in the country. Here, I compiled and analyzed a list of 182 publications in scientific journals, and 23 thesis, reports and books in which marine organisms, environments and marine and atmospheric processes from Bahía Culebra or in which the Bay are mentioned is presented and analyzed. The majority of the publications, starting with a paper from 1922 on a polychaete worm, are on biodiversity and ecology. The are no publications on some environments, for example the benthonic fauna of soft bottoms, or on some taxa, for example, flat worms. More work is needed on fisheries and management of the organisms and environments of Bahía Culebra.

Bahía Culebra se locoaliza en la parte norte de la costa Pacífica de Costa Rica. Es una región de afloramiento estacional, rica en ambientes y organismos marinos, y además, la zona de mayor desarrollo turístico del país. En este trabajo compilo y analizo una lista de 182 publicaciones en revista científcas y 23 tesis, informes y libros sobre organismos, ambientes y procesos marinos y atmosféricos en Bahía Culebra o donde se menciona la Bahía, se presentan y analizan. La gran mayoría de los trabajos, empezando en 1922 con la descripción de un poliqueto, son sobre biodiversidad y ecología. Faltan trabajos sobre algunos ambientes de la bahía, por ejemplo, el bentos de los fondos blandos, y grupos de organismos, por ejemplo, sobre gusanos planos de vida libre. Faltan investigaciones sobre pesquería y manejo de los organismos y ambientes marinos de la Bahía.

Geología de Bahía Culebra, Guanacaste, Costa Rica / Geology of Bahía Culebra, Guanacaste, Costa Rica

The geology of Culebra Bay, Guanacaste, Costa Rica, is composed of volcanic rocks of oceanic crust; marine sediments deposited on the slope, continental platform and superficial zones nearby to the coast, pyroclastic rocks inset with continental sediments and recent Quaternary deposits. At the base of the stratigraphy sequence the massive basalts outcrop, sometimes as pillow, from Nicoya complex with aphanitic texture with olivine phenocrysts, augites and plagioclases. Into the same formation are included intrusives of massive gabro with pyroxene and plagiogranites with phenocrysts of plagioclases and hornblendite. Then limestones outcrop from El Viejo formation formed by colonies of reefs and limestone rocks. The Montezuma formation is composed of fossiliferous sandstone, facies of sandstone with cross-lamination and facies of sandstone and lutites. The Dacitas Carbonal are composed of lavas with pumice clasts and alteration minerals. The Bagaces formation is composed of several eruptive events with ignimbrites and possibly of a sand volcaniclastic sedimentary deposit. At the top of the stratigraphic sequence are included, product of factors such as colluvial erosion, and beach sand, areas of mangrove sediments and alluvium.

La geología de Bahía Culebra, Guanacaste, Costa Rica, está compuesta por rocas volcánicas de corteza oceánica; sedimentos marinos depositados en el talud, la plataforma continental y zonas someras cerca de la costa; secuencias de rocas piroclásticas intercaladas con sedimentos continentales y depósitos Cuaternarios recientes. En la base de la secuencia estratigráfica afloran los basaltos masivos, algunas veces en almohadilla, del Complejo de Nicoya con textura afanítica con fenocristales de olivino, augitas y plagioclasas. Dentro de la misma Formación se incluyen intrusivos de gabro masivos con piroxenos y plagiogranitos con fenocristales de plagioclasas y hornblenda. Seguidamente afloran las calizas de la Formación El Viejo constituida por colonias arrecifales e intercalaciones calcáreas. La Formación Montezuma compuesta por facies de arenisca media fosilífera, facies de arenisca media con laminación cruzada y facies rítmicas de areniscas y lutitas. Las Dacitas Carbonal están compuestas por lavas hexagonales y variaciones brechosas con clastos de pómez y minerales de alteración. La Formación Bagaces se constituye de varios eventos eruptivos con secuencias de ignimbritas y un depósito sedimentario posiblemente pluvial de arenas volcaniclásticas. En la parte superior de la secuencia estratigrafica se incluyen los depósitos producto de factores erosivos tales como coluvios, arenas de playa, sedimentos de zonas de manglar y aluviones.

Geologia e geomorfologia da estação ecológica Serra Geral do Tocantins / Geology and geomorphology of Serra Geral do Tocantins ecological station

Este trabalho trata de descrição básica da paisagem existente na Estação Ecológica Serra Geral do Tocantins, localizada na porção oriental do Estado do Tocantins e extremo oeste do Estado da Bahia, Brasil Central. Dois fatores do meio físico são abordados: a geologia, composta por litotipos sedimentares, e as formas de relevo, dada a predominância de chapadões e morros testemunhos na região, famosa pela presença das Dunas do Jalapão ao norte. Tal interação, esculturada sob clima típico de savana, produziu uma série de mosaicos com imensas peculiaridades paisagísticas. A Serra Geral do Tocantins é um planalto sedimentar esculpido na Bacia Sedimentar do Parnaíba. A área da Estação é caracterizada por pacotes de sedimentos predominantemente continentais, posteriores ao derrame basáltico ocorrido durante a Reativação Wealdeniana Juro-Cretácea. São arenitos de colorações brancas a vermelhas, extremamente friáveis, oriundos das acumulações de paleoclimas secos (áridos a semi-áridos) do Mesozóico, possivelmente contemporâneos ao Deserto Botucatu existente na Bacia do Paraná, embora as camadas mais superiores possam estar associadas a ambiente flúvio-lacustre. As formas de relevo envolvem uma seqüência de chapadas e patamares caracterizando formas estruturais com rebordos festonados e rampas escalonadas em formas erosivas. As chapadas são constituídas por sedimentos cretáceos e configuram grandes unidades de relevo em mesa penetradas por vales pedimentados, com bordas escarpadas e anfiteatros largos, que atacados por ciclos de erosão pós-cretáceos resultaram em patamares escalonados e arrasados em pediplanos que descem rumo ao curso do Rio Tocantins. A presença de inúmeros relevos residuais colabora nos contrastes geomorfológicos. Os processos morfogenéticos predominantemente mecânicos podem ser divididos em quatro fases de esculturação que resultaram na dissecação diferenciada. A compartimentação do relevo permite apontar algumas considerações sobre a distribuição geográfica da fauna na área da Estação Ecológica e seu entorno, pois em parte esta relação pode ser determinada pelos escalonamentos topográficos decorrentes do aparecimento das unidades geomorfológicas. A maior barreira geográfica foi criada durante o Neoproterozóico, separando as formas de relevo dos patamares escalonados; os basculamentos mesozóicos produziram os chapadões que, pela erosão mecânica, formaram pedimentos que foram aos poucos coalescidos durante o Cretáceo Superior até o Terciário Superior; tal processo resultou nos relevos residuais que, juntamente com a reativação de falhas antigas, favoreceu o isolamento entre os compartimentos biológicos; este processo continuou durante o Quaternário em razão das alternâncias climáticas de períodos semi-áridos a úmidos, promovendo a retomada da erosão mecânica e a formação de planícies fluviais.

This work presents a basic description of Serra Geral do Tocantins Ecological Station, located in the eastern part of Tocantins State and western part of Bahia State, Central Brazil. Two main factors of physical environment are treated: geology, composed by sedimentary litotypes, and the relief forms, due to predominance of mesetas and inselbergs in the region, famous for Jalapão Dunes in the north. This interaction, sculpted under typical savanna climate, has turned out into a mosaic series with immense landscape peculiarities. Serra Geral do Tocantins is a sedimentary plateau sculpted at Sedimentary Basin of Parnaiba. The Ecological Station's area is featured by sedimentary packs mainly continental, subsequent from basaltic extrusion that occurred during Wealdenian Reactivation in the Jura-Cretaceous period. It is composed by sandstones whose colors changes from pale to red ones, extremely friable, originated from dry paleoclimate accumulations (arid to semi-arid ones) of Mesozoic. It is possible to be related to contemporary dry Mesozoic period of Parana's Basin (Botucatu Desert), though upper layers can be from fluvial-lake environment. The relief forms involve mesetas and level sequences characterized by structural features with retreated edges and step levels into erosive forms. The mesetas are filled with cretaceous sediments and configure great plateau relief units penetrated by pedimented valleys, with scarped edges and large amphitheatres. Its attack by post-cretaceous erosion resulted into step levels whose softened surface produced pediplains that run to Tocantins River course. The very existence of considerable numbers of residual landforms contributes to the geomorphologic contrast. The predominance of the mechanical morphogenetic process can be divided into four sculptural phases resulting in differential dissection. Based on relief compartments it is possible to point out some considerations about the geographical distribution of the fauna in the Ecological Station's area and its surroundings, because at least part of it can be related to the topographic step-levels forms originated from geomorphological units. The biggest geographical barrier was created during Neoproterozoic, dividing the step-levels relief forms; the Mesozoic tilting produced the mesetas which by mechanical erosion formed pediments that suffered coalescence from Upper Cretaceous to Upper Tertiary. This process resulted into residual landforms, whose action in combination with ancient faults reactivations helped the isolation of biological compartments; continuing during Quaternary due to alternations of semi-arid to humid periods, mechanical erosion was initiated again and fluvial plains were formed.

"The Pyrenees are not hollow": the mountain as a boundary object / "Os Pirineus não são ecos": a montanha como objeto de fronteira

In Toulouse, around 1850, a controversy about the structure of the Pyrenees pitted observatory director Frederic Petit against geology professor Alexandre Leymerie. The object of the debate was an assumption formulated by Petit: that the inside of the Pyrenees was practically hollow. This proposal was based on work that Petit initiated in order to determine the latitude of Toulouse. The debates, which took place within the Toulouse Academy of Science and also in local newspapers, illustrate the organization of disciplinary spaces in the nineteenth century. Petit defended his research method based on calculation; the geologist's perspective was from the field. The emergence of the less mathematical science of geology came up against nineteenth-century astronomical practices, centered on calculation. Dissected by calculation or by visual observation, the mountain was an object of controversy from the perspective of distinct scientific practices.

Em Toulouse, por volta de 1850, uma controvérsia sobre a estrutura dos Pirineus colocou o diretor do Observatório, Frederic Petit, contra o professor de geologia Alexandre Leymerie. O motivo do debate foi a hipótese formulada por Petit: o interior dos Pirineus era praticamente oco. A proposição baseava-se no trabalho que Petit iniciara para determinar a latitude de Toulouse. Os debates, que tiveram lugar na Academia de Ciências de Toulouse e também em periódicos locais, ilustram a organização dos espaços disciplinares no século XIX. Petit defendia seu método de pesquisa baseado em cálculos; a perspectiva do geólogo provinha do campo. A emergência da ciência geológica, menos matemática, vinha de encontro às práticas da astronomia daquele século. Analisada por cálculos ou pela observação visual, a montanha foi um objeto de controvérsia entre diferentes práticas científicas.

Breves Notícias Sobre a Geologia dos Estados do Paraná e Santa Catarina

The present short survey of the geology of the States of Paraná and Santa Catarina was written as a text to accompany sketches for the revision of the GEOLOGICAL MAP OF SOUTH AMERICA. It contains the results of geologic research up to the year 1947 in most concise form, without going into detail. As requested, the occurrence of useful minerals was not considered in the summary, and the list of bibliographical references has been condensed to the uttermost. Inasmuch as the author treated the Passa Dois Series in more detail, due to the reorganization of the Gondwana beds, the Archean and the Algonkian had to be reduced to the minimum. This was possible, since the innumerable details of the phenomena in the crystalline complex could not be represented in a geologic map of the given scale. The reorganization of the geologic constituents of Paraná and Santa Catarina is summarized in Stratigraphic Table nº 2, and is explained by the enclosed sketches.

Die vorliegende kurze Übersicht zur Geologie der Staaten Paraná und Santa Catarina wurde als Begleittext zur Skizze für die Revision der GEOLOGICAL MAP OF SOUTH AMERICA verfasst. Sie enthält die Ergebnisse der geologischen Forschung bis zum Jahre 1947 in gedrängtester Form, wobei auf Einzelheiten nicht eingegangen wird. Auf ausdrücklichen Wunsch sind die Vorkommen nutzbarer Mineralien in der Übersicht nicht berücksichtigt, und auch das Literatur-Verzeichnis auf das Äusserste eingeschränkt worden. Da der Verfasser im Hinblick auf die Neugliederung der Gondwana-Schichten die Serie Passa Dois etwas eingehender behandelte, mussten dafür Archaeikum und Algonkium auf das Mindestmass gekürzt werden. Das war dadurch möglich, dass bei den mannigfachen Einzelheiten der Erscheinungen im kristallinen Komplex diese bei dem für die geologische Karte vorgesehenen Masstab doch nicht dargestellt werden konnten. Die Neugliederung der geologischen Baustoffe von Paraná und Santa Catarina ist in der stratigrafischen Tabelle nº 2 zusammengefasst und wird durch die beigefügten Skizzen erläutert.