Navegando por Autor "S. Auler, Augusto"

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Artigo
Global distribution of carbonate rocks and karst water resources
(2021-04-21) Goldscheider, Nico; Chen, Zhao; S. Auler, Augusto; Bakalowicz, Michel; Broda, Stefan; Drew, David; Hartmann, Jens; Jiang, Guanghui; Moosdorf, Nils; Stevanovic, Zoran; Veni, George
Karst regions offer a variety of natural resources such as freshwater and biodiversity, and many cultural resources. The World Karst Aquifer Map (WOKAM) is the first detailed and complete global geodatabase concerning the distribution of karstifiable rocks (carbonates and evaporites) representing potential karst aquifers. This study presents a statistical evaluation of WOKAM, focusing entirely on karst in carbonate rocks and addressing four main aspects: (1) global occurrence and geographic distribution of karst; (2) karst in various topographic settings and coastal areas; (3) karst in different climatic zones; and (4) populations living on karst. According to the analysis, 15.2% of the global ice-free continental surface is characterized by the presence of karstifiable carbonate rock. The largest percentage is in Europe (21.8%); the largest absolute area occurs in Asia (8.35 million km2). Globally, 31.1% of all surface exposures of carbonate rocks occur in plains, 28.1% in hills and 40.8% in mountains, and 151,400 km or 15.7% of marine coastlines are characterized by carbonate rocks. About 34.2% of all carbonate rocks occur in arid climates, followed by 28.2% in cold and 15.9% in temperate climates, whereas only 13.1 and 8.6% occur in tropical and polar climates, respectively. Globally, 1.18 billion people (16.5% of the global population) live on karst. The highest absolute number occurs in Asia (661.7 million), whereas the highest percentages are in Europe (25.3%) and North America (23.5%). These results demonstrate the global importance of karst and serve as a basis for further research and international water management strategies.
Artigo
Stromatolites in Caves in Southeastern Brazil and their Importance to Geoconservation
(2020-06-03) G. Vasconcelos, André; S. Bittencourt, Jonathas; F. Eliziário, Neuber; M. Kraemer, Bruno; S. Auler, Augusto
This article presents a detailed description of stromatolites formed simultaneously with caves’ bedrock, within karstic areas in Southeastern Brazil. We discuss the importance of such fossils for geoconservation and their legal preservation under the Brazilian law. Six caves are described with occurrences of Conophyton-type stromatolites. All those caves are located in the State of Minas Gerais, one of which in the Arcos-Pains-Doresópolis Karst (Bambuí Group) and the others in the Vazante-Paracatu-Unaí Karst (Vazante Group). In general, the stromatolite columns are not exquisitely preserved, yet conspicuously exposed in cross section and lateral view. The stromatolite caves are easily accessed, making them suitable for scientific and educational activities to both academic and non-specialized public. Yet, such activities should rely on the implementation of a management plan for monitoring potential damage due to anthropic interference. Given the rarity of caves with fossils embedded in their host rocks, these structures should be treated with the status of maximum importance for conservation, according to the Brazilian legislation, thereby ensuring their permanent protection, with the support of the public entities for environment and nature.