| 1. |
- Baratoux, L., et al.
(författare)
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New U–PB baddeleyite ages of mafic dyke swarms of the west African and amazonian cratons : Implication for their configuration in supercontinents through time
- 2019
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Ingår i: Springer Geology. - Singapore : Springer Singapore. - 2197-9545 .- 2197-9553. ; , s. 263-314
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Bokkapitel (refereegranskat)abstract
- Eight different generations of dolerite dykes crosscutting the Paleoproterozoic basement in West Africa and one in South America were dated using the high precision U–Pb TIMS method on baddeleyite. Some of the individual dykes reach over 300 km in length and they are considered parts of much larger systems of mafic dyke swarms representing the plumbing systems for large igneous provinces (LIPs). The new U–Pb ages obtained for the investigated swarms in the southern West African Craton (WAC) are the following (oldest to youngest): 1791 ± 3 Ma for the N010° Libiri swarm, 1764 ± 4 Ma for the N035° Kédougou swarm, 1575 ± 5 for the N100° Korsimoro swarm, ~1525–1529 Ma for the N130° Essakane swarm, 1521 ± 3 Ma for the N90° Sambarabougou swarm, 915 ± 7 Ma for the N070° Oda swarm, 867 ± 16 Ma for the N355° Manso swarm, 202 ± 5 Ma and 198 ± 16 Ma for the N040° Hounde swarm, and 200 ± 3 Ma for the sills in the Taoudeni basin. The last ones are related to the Central Atlantic Magmatic Province (CAMP) event. The Hounde swarm is oblique to the dominant radiating CAMP swarm and may be linked with the similar-trending elongate Kakoulima intrusion in Guinea. In addition, the N150° Käyser swarm (Amazonian craton, South America) is dated at 1528 ± 2 Ma, providing a robust match with the Essakane swarm in a standard Amazonia-West African craton reconstruction, and resulting in a combined linear swarm >1500 km by >1500 km in extent. The Precambrian LIP barcode ages of c. 1790, 1765–1750, 1575, 1520, 915. 870 Ma for the WAC are compared with the global LIP record to identify possible matches on other crustal blocks, with reconstruction implications. These results contribute to the refinement of the magmatic ‘barcode’ for the West African and Amazonian cratons, representing the first steps towards plausible global paleogeographic reconstructions involving the West African and Amazonian cratons.
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| 2. |
- Dufresnes, Christophe, et al.
(författare)
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Fifteen shades of green : The evolution of Bufotes toads revisited
- 2019
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 141
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Tidskriftsartikel (refereegranskat)abstract
- The radiation of Palearctic green toads (Bufotes) holds great potential to evaluate the role of hybridization in phylogeography at multiple stages along the speciation continuum. With fifteen species representing three ploidy levels, this model system is particularly attractive to examine the causes and consequences of allopoly-ploidization, a prevalent yet enigmatic pathway towards hybrid speciation. Despite substantial efforts, the evolutionary history of this species complex remains largely blurred by the lack of consistency among the corresponding literature. To get a fresh, comprehensive view on Bufotes phylogeography, here we combined genome-wide multilocus analyses (RAD-seq) with an extensive compilation of mitochondrial, genome size, niche modelling, distribution and phenotypic (bioacoustics, morphometrics, toxin composition) datasets, representing hundreds of populations throughout Eurasia. We provide a fully resolved nuclear phylogeny for Bufotes and highlight exceptional cyto-nuclear discordances characteristic of complete mtDNA replacement (in 20% of species), mitochondrial surfing during post-glacial expansions, and the formation of homoploid hybrid populations. Moreover, we traced the origin of several allopolyploids down to species level, showing that all were exclusively fathered by the West Himalayan B. latastii but mothered by several diploid forms inhabiting Central Asian lowlands, an asymmetry consistent with hypotheses on mate choice and Dobzhansky-Muller incompatibilities. Their intermediate call phenotypes potentially allowed for rapid reproductive isolation, while toxin compositions converged towards the ecologically-closest parent. Across the radiation, we pinpoint a stepwise progression of reproductive isolation through time, with a threshold below which hybridizability is irrespective of divergence (< 6My), above which species barely admix and eventually evolve different mating calls (6-10My), or can successfully cross-breed through allopolyploidization (> 15My). Finally, we clarified the taxonomy of Bufotes (including genetic analyses of type series) and formally described two new species, B. cypriensis sp. nov. (endemic to Cyprus) and B. perrini sp. nov. (endemic to Central Asia). Embracing the genomic age, our framework marks the advent of a new exciting era for evolutionary research in these iconic amphibians.
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| 3. |
- Ernst, Kathleen M., et al.
(författare)
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Identifying climate service production constraints to adaptation decision-making in Sweden
- 2019
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Ingår i: Environmental Science and Policy. - : ELSEVIER SCI LTD. - 1462-9011 .- 1873-6416. ; 93, s. 83-91
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Tidskriftsartikel (refereegranskat)abstract
- Climate change adaptation efforts continue to increase as the impacts of climate change increase, intensify, and become more apparent. However, many adaptation efforts fail to result in adaptation actions. This inaction has been linked to several constraining factors including a lack of actionable information for adaptation decision-making processes. We wonder if climate service producers face constraints as they try to create and deliver actionable information for adaptation decision-making efforts? This paper draws on semi-structured interviews and participant-observations across climate service production environments in Sweden to answer our research question and fords that climate service producers engage in research, coordination, and communication to varying degrees and experience constraints related to the production and dissemination of actionable information and stakeholder engagement, as well as funding, professional, and institutional constraints. Some constraints are experienced differently by climate service producers depending on their specific role, institutional affiliation, agency, and experience. Additionally, some climate service production constraints create or exacerbate additional constraints for adaptation decision-making stakeholders. Therefore, climate service production constraints limit the effectiveness of climate services, and overcoming them would help make progress towards more adaptation implementation in specific contexts. However, for adaptation actions to be widespread, the production and dissemination of climate services must be met with additional support and guidance for adaptation efforts beyond the provision of actionable information.
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| 4. |
- Gladkochub, D. P., et al.
(författare)
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РАСШИРЕНИЕ АРЕАЛА ТИМПТОНСКОЙ КРУПНОЙ МАГМАТИЧЕСКОЙ ПРОВИНЦИИ (~1.75 МЛРД ЛЕТ) СИБИРСКОГО КРАТОНА
- 2019
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Ingår i: Geodynamics and Tectonophysics. - 2078-502X. ; 10:4, s. 829-839
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Tidskriftsartikel (refereegranskat)abstract
- We present new geochronological data on dolerites from the Chaya dyke swarm of the Baikal inlier of the Siberian craton. The U-Pb dating of baddeleyite from one dyke located at the SW end of the Chaya dyke swarm yielded an age of 1752±6 Ma, similar to the previously obtained age of a dyke in the NE end of this swarm. These ages establish an age of 1752 Ma for a unified Chaya dyke swarm that extends for more than 200 km in the Baikal inlier of the Siberian craton. These new data confirm that the entire Chaya dyke swarm (as well as the Timpton-Algamay and Eastern Anabar swarms) is a part of an overall radiating dyke swarm belonging to the Late Paleoproterozoic Timpton Large Igneous Province (LIP), the center of which is located in the middle section of the Vilyuy river flow. Thus, the LIP is enlarged to include the area further west in the Siberian craton.
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| 5. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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| 9. |
- Orgel, Csilla, et al.
(författare)
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Gridmapping the Northern Plains of Mars: A New Overview of Recent Water‐ and Ice‐Related Landforms in Acidalia Planitia.
- 2019
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Ingår i: Journal of Geophysical Research - Planets. - 2169-9100. ; 124:2, s. 454-82
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Tidskriftsartikel (refereegranskat)abstract
- We used a grid‐mapping technique to analyze the distribution of 13 water‐ and ice‐related landforms in Acidalia Planitia as part of a joint effort to study the three main basins in the northern lowlands of Mars, that is, Acidalia, Utopia, and Arcadia Planitiae. The landforms were mapped at full Context Camera resolution along a 300‐km‐wide strip from 20°N to 84°N. We identified four landform assemblages: (1) Geologically recent polar cap (massive ice), which superposes the latitude‐dependent mantle (LDM) (LA1); (2) ice‐related landforms, such as LDM, textured terrain, small‐scale polygons, scalloped terrain, large‐scale viscous flow features, and gullies, which have an overlapping distribution (LA2); (3) surface features possibly related to water and subsurface sediment mobilization (LA3; kilometer‐scale polygons, large pitted mounds, small pitted mounds, thumbprint terrain); and (4) irregularly shaped pits with raised rims on equator‐facing slopes. Pits are likely the result of an energetic release of volatiles (H2O, CO2, and CH4), rather than impact‐, volcanism‐, or wind‐related processes. LDM occurs ubiquitously from 44°N to 78°N in Acidalia Planitia. Various observations suggest an origin of air fall deposition of LDM, which contains less ice in the uppermost tens of meters in Acidalia Planitia than in Arcadia and Utopia Planitiae. However, LDM may be thicker and more extended in the past in Acidalia Planitia. The transition between LDM‐free terrain and LDM is situated further north than in Utopia and Arcadia Planitiae, suggesting different past and/or present climatic conditions among the main basins in the northern lowlands.
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| 10. |
- Ramsdale, Jason D., et al.
(författare)
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Gridmapping the northern plains of Mars: Geomorphological, Radar and Water-Equivalent Hydrogen results from Arcadia Plantia.
- 2019
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Ingår i: Journal of Geophysical Research - Planets. - 2169-9100. ; 124:2, s. 504-27
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Tidskriftsartikel (refereegranskat)abstract
- A project of mapping ice‐related landforms was undertaken to understand the role of subsurface ice in the northern plains. This work is the first continuous regional mapping from CTX (ConTeXt Camera, 6 m/pixel; Malin et al., 2007) imagery in Arcadia Planitia along a strip 300 km across stretching from 30°N to 80°N centered on the 170°W line of longitude. The distribution and morphotypes of these landforms were used to understand the permafrost cryolithology. The mantled and textured signatures occur almost ubiquitously between 35°N and 78°N and have a positive spatial correlation with inferred ice stability based on thermal modeling, neutron spectroscopy, and radar data. The degradational features into the LDM (latitude‐dependent mantle) include pits, scallops, and 100‐m polygons and provide supporting evidence for subsurface ice and volatile loss between 35 and 70°N in Arcadia with the mantle between 70 and 78°N appearing much more intact. Pitted terrain appears to be much more pervasive in Arcadia than in Acidalia and Utopia suggesting that the Arcadia study area had more widespread near‐surface subsurface ice and thus was more susceptible to pitting or that the ice was less well buried by sediments. Correlations with ice stability models suggest that lack of pits north of 65–70°N could indicate a relatively young age (~1 Ma); however, this could also be explained through regional variations in degradation rates. The deposition of the LDM is consistent with an air fall hypothesis; however, there appears to be substantial evidence for fluvial processes in southern Arcadia with older, underlying processes being equally dominant with the LDM and degradation thereof in shaping the landscape.
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