16S rRNA Gene Amplicon Sequencing Data of the Iron Quadrangle Ferruginous Caves (Brazil) Shows the Importance of Conserving This Singular and Threatened Geosystem

The Iron Quadrangle (IQ) is one of the main iron ore producing regions of the world. The exploitation of its reserves jeopardizes the high biological endemism associated with this region. This work aimed to understand the diversity and bacterial potential associated with IQ caves. Floor and ceiling samples of seven ferruginous caves and one quartzite cave were collected, and their microbial relative abundance and diversity were established by 16S rRNA gene amplicon sequencing data. The results showed that ferruginous caves present higher microbial abundance and greater microbial diversity compared to the quartzite cave. Many species belonging to genera found in these caves, such as Pseudonocardia and Streptacidiphilus, are known to produce biomolecules of biotechnological interest as macrolides and polyketides. Moreover, comparative analysis of microbial diversity and metabolic potential in a biofilm in pendant microfeature revealed that the microbiota associated with this structure is more similar to the floor rather than ceiling samples, with the presence of genera that may participate in the genesis of these cavities, for instance, Ferrovum, Geobacter, and Sideroxydans. These results provide the first glimpse of the microbial life in these environments and emphasize the need of conservation programs for these areas, which are under intense anthropogenic exploration.

Geodesign Experiments in Areas of Social Vulnerability in the Iron Quadrangle, Minas Gerais, Brazil

This paper presents and discusses the use of methodologies for shared and participatory planning through Geodesign, in areas of irregular occupation and social vulnerability in the urban areas of the Iron Quadrangle, Minas Gerais, Brazil. It is illustrated by the development of four case studies with varying degrees of complexity, participation, and impact as a support for opinion building or decision making. The work encompasses different applications of digital support platforms, from web-based to off-line, as well as their methodological variations, adopted according to the goals of each case study. They vary according to space, the profile of the participants (ages), technological platform, methodological steps, but they all share support for opinion making. We conclude by suggesting optimal methodological choices for different contexts of social vulnerability, regarding the evolution of urban planning processes. We argue in favor of Geodesign as a framework for the planning of irregular housing occupations, as it is flexible enough to deal with different scenarios.

Planning and co-creation of Quadrilatero Ferrifero cultural landscape

The article presents results about Geodesign studies of the Iron Quadrangle (Quadrilátero Ferrífero – QF) that are under development since 2016, based on economic, environmental, and social approaches, with the goal to promote cultural landscape planning based on shared process, giving support to collective and individual opinion making. This paper has the goal do present the Brazilian Geodesign platform, called “GISColab”, that was first tested in QF case study. The QF area is characterized by conflicts of interests due to mining activities, urban growth, cultural heritage landscapes and the presence of areas of environmental protection. QF is especially important as part of the economic structure of the state of Minas Gerais (Brazil) but became globally known due to a couple of environmental disasters that caused the death of almost 300 people. In the first studies we used Steinitz´s framework (2012), but some difficulties in the process were observed, what led to the proposal of a new platform and framework, more adapted to inequalities related to access and use of information, so that people could really act as participants of all the steps. The new web-platform is based on Spatial Data Infrastructure (SDI), which receives a considerable amount of data and is open to receive further information via Web Map Service (WMS), which guarantees the users will construct, by themselves, judgments about these areas. It presents a shared process of decision making by digital dialogues, as by voting based on Delphi method. The platform and process are based on geovisualization, interoperability and the co-creation of ideas based on geo-collaboration.

Potential Bioinoculants for Sustainable Agriculture Prospected from Ferruginous Caves of the Iron Quadrangle/Brazil

Biocontrol and plant growth-promoting bacteria (PGPB) are important agricultural bioinoculants. This study aimed to prospect new potential bioinoculants for a more sustainable agriculture from ferruginous caves of the Brazilian Iron Quadrangle. Culturable bacteria, from seven caves and one canga soil sample, were evaluated for biocontroller activity of the phytopathogens Xanthomonas citri subsp. Citri—Xcc306 (citrus canker), Fusarium oxysporum—Fo (fusariosis), and Colletotrichum lindemuthianum—Cl89 (bean anthracnose). The ability of the superior candidates to solubilize inorganic phosphate, fix nitrogen, and produce hydrolytic enzymes and siderophores was then analyzed. Out of 563 isolates, 47 inhibited the growth of Xcc306 in vitro, of which 9 reduced citrus canker up to 68% when co-inoculated with the pathogen on host plants. Twenty of the 47 inhibited Fo growth directly by 51–73%, and 15 indirectly by 75–81%. These 15 inhibited Cl89 growth in vitro (up to 93% directly and 100% indirectly), fixed nitrogen, produced proteases and siderophores, showed motility ability, produced biofilm, and all but one solubilized inorganic phosphate. Therefore, 15 (2.66%) bacterial isolates, from the genera Serratia, Nissabacter, and Dickeya, act simultaneously as biocontrollers and PGPBs, and could be important candidates for future investigations in planta as an alternative to minimize the use of pesticides and chemical fertilizers through sustainable agricultural management practices.

Identificação dos leques aluviais dissecados do Quadrilátero Ferrífero (MG) através de critérios espaciais e sedimentológicos

O objetivo desse estudo foi identificar os depósitos de leques aluviais colmatados ao longo da base das escarpas do Quadrilátero Ferrífero. A referida identificação ocorreu primeiramente em gabinete, onde foram realizadas leituras de trabalhos relacionados a geomorfologia da região bem como a interpretação dos mapas geológicos disponíveis. Os dados obtidos em gabinete serviram de base para norteamento dos trabalhos de campo, onde foi possível analisar características espaciais, sedimentológicas e morfométricas dos depósitos de encosta e inferir sobre seu possível ambiente deposicional. Os trabalhos de campo foram direcionados a cinco depósitos localizados nas bordas Sul, Oeste e Noroeste do Quadrilátero Ferrífero cujos sedimentos estão posicionados de forma oblíqua ao vale principal com características faciológicas que remetem a fluxos de detritos desconfinados. Nos depósitos 1 e 2 foram verificadas diminuição granulométrica de montante para jusante, indicando brusca perda de energia. Essas características somadas as elevadas espessuras dos depósitos de fluxos de detritos permitiram inferir que tais acumulações compreendem leques aluviais inativos, atualmente em fase de dissecação pelos elementos erosivos naturais e antrópicos. Tais leques aluviais podem conter importantes informações a respeito do quadro paleoclimático e paleomorfológico da região, tendo potencial para contribuir com novos dados e aumentar o horizonte de interpretações a respeito da dinâmica paleoambiental quaternária regional. Identification of alluvial fans dissected from the Quadrilátero Ferrífero (MG) through spatial and sedimentological criteriaA B S T R A C TThis study aims to identify deposits of alluvial fans that were filled in along the base of the Iron Quadrangle escarpments. This identification occurred first in the office, where readings of works related to the geomorphology of the region were carried out, as well as the interpretation of the available geological maps. The data obtained in the office was the basis for guiding fieldwork, through which it was possible to analyze spatial, sedimentologic and morphometric characteristics of the slope deposits and to infer their possible depositional environment. The fieldwork was directed to five deposits located on the South, West and Northwest edges of the Iron Quadrangle whose sediments are placed obliquely to the main valley with faciological characteristics denoting unfinished debris flows. In deposits 1 and 2, there was a granulometric decrease from downstream to upstream, indicating an abrupt loss of energy. These characteristics added to the high thickness of the deposits of debris flows allowed to infer that such accumulations comprise inactive alluvial fans, currently in the dissection phase by natural and antropic erosive elements. Such alluvial fans may contain important information about the region's paleoclimatic and paleomorphological framework, with the potential of contributing with new data and increasing the range of interpretations regarding the regional quaternary paleoenvironmental dynamics.Keywords: Quaternary, sedimentary deposits, debris flow, paleogeography.

Panorama das barragens de rejeito de minério no Quadrilátero Ferrífero (MG) e suas implicações para a segurança hídrica da Região Metropolitana de Belo Horizonte-MG

<p>O presente trabalho objetiva investigar as lacunas legais no tocante à segurança de barragens de rejeito de minério nas bacias de contribuição dos mananciais que abastecem a Região Metropolitana de Belo Horizonte (RMBH), evidenciando suas implicações para a manutenção da quantidade e da qualidade das águas. Por conseguinte, é elaborado um panorama das barragens da bacia do Alto Rio das Velhas em termos espaciais e legais, principalmente quanto à conformidade em relação à Política Nacional de Segurança de Barragens (PNSB). Os resultados obtidos mostram uma série de lacunas nos aspectos legais das estruturas, sobretudo no tocante à estabilidade dos barramentos, cenário que, por sua vez, compromete a segurança hídrica dos mananciais e o abastecimento de água da RMBH.</p><p><span>Abstract</span></p><p>SCENERY OF ORE TAILINGS DAMS IN THE QUADRILÁTERO FERRÍFERO “IRON QUADRANGLE” (MG) AND IMPLICATIONS FOR WATER SECURITY IN THE METROPOLITAN REGION OF BELO HORIZONTE, MINAS GERAIS STATE, BRAZIL</p><p>This paper aims to investigate the legal gaps regarding the safety of ore tailings dams in the contribution basins of the water sources that supply the Metropolitan Region of Belo Horizonte, highlighting their implications for maintaining the quantity and quality of water. In this context is featured an overview of the spatial distribution and legal aspects of the dams in the Upper Velhas River basin, involving their compliance with the National Dam Safety Politics (PNSB). The results show many legal gaps, especially regarding the structural stability, which, in turn, compromises the water resources security and the regional water supply processes.</p>