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- Bernet, Matthias, et al.
(författare)
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Multidisciplinary petro-geo-thermochronological approach to ore deposit exploration
- 2019
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Ingår i: Ore Geology Reviews. - : Elsevier BV. - 0169-1368. ; 112:Sept.
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Forskningsöversikt (refereegranskat)abstract
- The continuous search for mineral resources such as gold, copper and base metals etc. requires a refined understanding of the thermal evolution and exhumation history of potential exploration targets, as only ore deposits can be exploited that have been exhumed to the surface or near to the surface. In order to better understand the exhumation history of the ore deposits a multidisciplinary approach using single grain geo- and thermochronology double/triple dating in combination with other geochemical, fluid inclusion and petrological analyses, can significantly support prospecting for such resources, particularly in frontier areas, where little geological information exists. Geo-thermochronology provides information on the timing of initial host rock crystallization, ore deposit formation and subsequent exhumation as the thermal history can be modelled and exhumation rates can be determined. Here we present a methodological outline on which single-grain double/triple-dating techniques can be used, what sampling strategies may be applied, and how the data may be interpreted.
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- Perez-Escobar, Oscar A., et al.
(författare)
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The origin and speciation of orchids
- 2024
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Ingår i: NEW PHYTOLOGIST. - 0028-646X .- 1469-8137.
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Tidskriftsartikel (refereegranskat)abstract
- Orchids constitute one of the most spectacular radiations of flowering plants. However, their origin, spread across the globe, and hotspots of speciation remain uncertain due to the lack of an up-to-date phylogeographic analysis. We present a new Orchidaceae phylogeny based on combined high-throughput and Sanger sequencing data, covering all five subfamilies, 17/22 tribes, 40/49 subtribes, 285/736 genera, and c. 7% (1921) of the 29 524 accepted species, and use it to infer geographic range evolution, diversity, and speciation patterns by adding curated geographical distributions from the World Checklist of Vascular Plants. The orchids' most recent common ancestor is inferred to have lived in Late Cretaceous Laurasia. The modern range of Apostasioideae, which comprises two genera with 16 species from India to northern Australia, is interpreted as relictual, similar to that of numerous other groups that went extinct at higher latitudes following the global climate cooling during the Oligocene. Despite their ancient origin, modern orchid species diversity mainly originated over the last 5 Ma, with the highest speciation rates in Panama and Costa Rica. These results alter our understanding of the geographic origin of orchids, previously proposed as Australian, and pinpoint Central America as a region of recent, explosive speciation.
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