43 research outputs found
A new methodological contribution for the geodiversity assessment: applicability to CearĂĄ State (Brazil)
The concept of geodiversity aggregates the abiotic elements of nature and promotes the geoconservation. The main objective of this work is to contribute to the upgrade of the method for the assessment and quantification of geodiversity proposed by Pereira et al. (2013). The method is based on the superposition of a regular grid of 12 à 12 km on different maps (lithology, geomorphology, soil, paleonthology, mineral and geological energy resources) at scales of 1:250,000 to 1:600,000. In addition to other up- grades, the water resources are regarded here as a new com- ponent to consider when quantifying geodiversity. The sum of these maps generated the quantitative Map of Geodiversity Indices and the Map of Geodiversity Assessment, ranging from very low to very high geodiversity. The analysis of the geodiversity map of the State of Cearå (Brazil) shows the applicability and advantage of this method, highlighting two regions with higher levels of geodiversity (Northwest and South) and another region with the lowest levels (SertÔes Cearenses). The results also allowed the characterization of the State of Cearå concerning the individual components of the geodiversity, especially the water resources. Geodiversity indices and maps are comprehensive and user-friendly data in the territorial planning, considering the geodiversity either as a whole, or each of its components, especially the more sensi- tive such as fossil conservation, and water, mineral, and non- renewable energy resources management.The authors express their gratitude to the Brazilian
research fostering institution "Coordenação de Aperfeiçoamento de
Pessoal de NĂvel Superior" (CAPES) for awarding the CiĂȘncia Sem
Fronteiras (CsF) PhD scholarship that enabled this work. This work was
partially co-funded by the European Union through the European Regional
Development Fund, based on COMPETE 2020 (Programa Operacional da
Competitividade e Internacionalização), project ICT (UID/GEO/04683/
2013) with reference POCI-01-0145-FEDER-007690 and national funds
provided by Fundação para a CiĂȘncia e Tecnologia
Out of Amazonia: late-Holocene climate change and the TupiâGuarani trans-continental expansion
The late Holocene expansion of the Tupi-Guarani languages from southern Amazonia to SE South America constitutes one of the largest expansions of any linguistic family in the world, spanning ~ 4000 km between latitudes 0°S and 35°S at about 2500 yr B.P. However, the underlying reasons for this expansion are a matter of debate. Here, we compare continental-scale palaeoecological, palaeoclimate, and archaeological datasets, to examine the role of climate change in facilitating the expansion of this forestfarming
culture. Because this expansion lies within the path of the South American Low-Level Jet, the key mechanism for moisture transport across lowland South America, we were able to explore the relationship between climate change, forest expansion, and the Tupi-Guarani. Our data
synthesis shows broad synchrony between late Holocene increasing precipitation and southerly expansion of both tropical forest and Guarani archaeological sites â the southernmost branch of the Tupi-Guarani. We conclude that climate change likely facilitated the agricultural expansion of the Guarani forest-farming culture by increasing the area of forested landscape that they could exploit, showing a prime example of ecological opportunism