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Item type:Publication, Revealing inherited Precambrian crustal structure of the Vaupés Arch in the Colombian Amazonian Craton using teleseismic receiver functions and gravity spectral analysis(Taylor and Francis Ltd., 2026-01-01)Uncovering the crustal structure is essential for understanding the tectonic history of a region. However, such analysis in remote and poorly exposed areas such as the Colombian Amazonian Craton is often challenging due to limited geological and geophysical data. This research presents a new regional Moho model for the southeastern Amazonian region in Colombia, encompassing the Sub-Andean basins and part of the northwestern Amazonian Craton. We combined Moho depth estimates from gravity analysis, using a 2D radially averaged power spectrum, with those derived from receiver functions using the H-k stacking technique at five seismic stations. The resulting Moho map reveals notable crustal heterogeneities along the NW-SE trending Vaupés Arch, with depths ranging from 33 to 51 km. In the light of the limited evidence of Phanerozoic tectonic activity in the Colombian Amazonian Craton and the inconsistency between Moho depths and present-day topography as indicated by an isostatic model, we suggest that the observed Moho depth variations likely reflect a polyphase history of Precambrian contraction and extension in the NW Amazonian Craton. This history is linked to Neoproterozoic rifting during Rodinia's break-up, which led to discontinuous crustal thinning in crustal domains previously thickened by Paleo-Mesoproterozoic orogenic pulses and the compressional phases of the Putumayo Orogen. Our findings underscore the value of integrating geophysical methods to better understand the tectonic evolution of cratonic regions with sparse surface data. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Early Miocene magmatism in the Western Cordillera of Colombia: implications for magma source and evolution(Taylor and Francis Ltd., 2026-01-01)Lower Miocene plutons exposed in the Western Cordillera of Colombia record the reinitiation of continental arc magmatism in the Northern Andes after a period of magmatic quiescence between the Late Eocene and Early Miocene. Petrography, U-Pb zircon geochronology, whole-rock geochemistry, mineral chemistry, and zircon Hf isotope data from these plutons are used to reconstruct the Miocene magmatic evolution in the Colombian Andes and understand its relation with the major plate-tectonic reorganization experienced by the NW South American continental margin during the Lower Miocene. We examined a suite of gabbros, granodiorites and tonalites from Danubio, Pance and Tatamá plutons, formed between 21 Ma and 15 Ma. Gabbros present highly positive εHf values (+13.5 and + 11.5) with low Th/La and La/Yb ratios, and granodiorites and tonalites present lower εHf values (+14.3 to + 6.4). The results of this contribution show a major asthenospheric source with absent or minor melting of subducted sediments, and contribution of oxidized aqueous fluids. The compositional diversification of these magmas was controlled by fractional crystallization and, in the Tatamá pluton, also by local assimilation of continental crust at lower crustal levels of the upper plate. Subsequently, these magmas were emplaced in the Cretaceous to Palaeogene volcanic and sedimentary rocks in the uppermost crust. The renewed magmatic activity recorded by the studied plutons suggests a normal to step subduction of the elder Farallon Plate during the Neogene subduction re-organization in the Colombian Andes, as well as the local presence of continental crust fragments in the lower crust of the Western Cordillera of Colombia.