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Item type:Publication, Forum communication comment on “A multidisciplinary overview of the lower Miño River terrace system (NW Iberian Peninsula)” by E. Méndez-Quintas et al(Elsevier, 2020-11-10)The paper by E. Méndez-Quintas et al. (2020) aims to give an interdisciplinary overview of the lower Miño River terrace record in NW Iberia by combining geological and archaeological data. The authors also pretend to re-interpret the geological-geomorphological evolution of this river by presenting new data and by comparing them to data published in our five related papers. However, a wrong interpretation of the data they present as well as incorrect and selective citations of ours lead to the production of a publication containing numerous errors. The most flagrant ones are the mapping of fluvial terraces on one side of the river only and an incorrect interpretation of the sedimentological information used to correlate terrace remnants along-river. This results in incorrect longitudinal profile reconstructions and an improper proposal of the evolution of the Miño terraces that is even contradicted by the data they present. On the upside, the ages of the Porto Maior terrace site published by these authors confirm our previously published longitudinal profile reconstructions and evolutionary model of the Miño valley. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, First record of OSL‐dated fluvial sands in a tropical Andean cave reveals rapid late Quaternary tectonic uplift(Wiley, 2020-12-05)Abstract We present the first results of OSL‐dated fluvial sands extracted from a riverside cave in the tropical Andes. The excellent agreement between the ages of the various samples allowed the calculation of a late Quaternary valley incision rate forced by ongoing uplift of an active Subandean fault‐propagation fold in NE Peru. A structural cross‐section was constructed to understand the relationship between the geometry of the fault‐propagation fold, historical damaging earthquakes and the cave system. The calculated uplift rate is 2.3 to 2.6 mm a−1 over the past 70 ka and can be directly linked to active propagation of west‐verging basement thrusts. It is similar to uplift rates calculated from fluvial terraces in the Subandes of Colombia and Venezuela. The results will help to better assess the seismic hazard and confirm that OSL dating of fluvial sands in caves is a powerful tool to quantify uplift rates of active mountain fronts.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Pliocene river capture and incision of the northern altiplano: Machu Picchu, Peru(Geological Society of London, 2020-01-01)The Abancay Deflection, forming the northern edge of the Altiplano in the Peruvian Andes, is a remarkable geomorphological feature marking the along-strike segmentation of the Andes. Little is known about the timing and spatial distribution of exhumation in this area. To constrain the exhumation history of the Abancay Deflection and its drivers, we present apatite (U–Th)/He and fission-track thermochronology data from samples collected along an elevation transect at Machu Picchu. Geomorphological analysis demonstrates recent and continuing drainage reorganization recorded by the spatial distribution of the normalized steepness index ( k sn ) and normalized integrated drainage area ( χ ) parameters. Thermochronologically derived cooling rates are converted into exhumation using regionally constrained geothermal gradients between 16 and 26°C km −1 . Time–temperature inversions imply steady and slow exhumation (<0.05 km Ma −1 ) between 20 and 4 Ma, followed by rapid exhumation (>0.9 km Ma −1 ) since 4 Ma. The timing of rapid exhumation, combined with the geomorphological analysis, suggests that fluvial capture of the previously endorheic Altiplano by the Urubamba River drove recent incision and exhumation. Depending on the value of the geothermal gradient used, total exhumation since 4 Ma can be explained by river incision alone or requires additional exhumation driven by tectonics, possibly associated with movement on the Apurimac fault. Supplementary material: Additional information is available at 10.6084/m9.figshare.c.51773431 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A 121-ka record of Western Andean fluvial response to suborbital climate cycles recorded by rhythmic grain size variations of the Lima fluvial fan(John Wiley and Sons Ltd, 2024-06-30)A complete, fluvial stratigraphic record for the last glacial period of the Western Andes in Peru is not available due to preservation issues and spatial variability in sedimentation. Deposits are typically restricted to incomplete records of fluvial terraces or localised occurrences of alluvial fans and landslides. These landforms are thought to have formed under a regime of climate cyclicity controlling increases in precipitation. Because of the fragmented preservation of these deposits, as well as dating uncertainties, it remains unclear if orbital climate cycles, such as the precession cycle, or suborbital cycles, such as the wet Heinrich events, are driving Andean sedimentation. In this paper, we try to answer this question through a sedimentological–stratigraphical analysis of a much more complete sedimentary sequence than usually found in the region. We present the results of a grain size analysis of 5000 clasts and 13 new luminescence ages of a 52-m-long, stratigraphic section of the Lima fluvial fan in Peru. Bayesian age–depth modelling resulted in a robust chronostratigraphic framework and derived sedimentation rates. The stratigraphic record registered sedimentation from 121.7 ± 4 to (Formula presented.) ka. Three major sedimentation periods occurred between 121.7 to (Formula presented.), 87 ± 1 to (Formula presented.), and (Formula presented.) to (Formula presented.) ka. These periods registered various unconformities and coarsening–fining upward sequences which chronologically correlate to suborbital pluvial periods, recognised from speleothems and lake records, that drove fluvial deposition. They also correlate with the timing of other recognised sedimentation events throughout the Western Andes. Marine regression resulted in fan progradation and not in incision. The Lima fan stratigraphy represents therefore the most complete, last glacial fluvial record for the Peruvian Western Andes to date and it highlights the potential of fluvial fans as recorders of suborbital climate variability.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The fluvial architecture of the Amazonian neighborhood of Belen, Peru(Taylor & Francis, 2026-01-01)The city of Iquitos (Peruvian Amazon) is composed of flood-prone urban communities that relate collective and economic activities to the river dynamics. The research objective is to describe architecture types of the Belen neighborhood (one of the most commercially and touristically important areas of Iquitos) during the Amazonian fluvial dynamics in the flood and ebb cycle of the Itaya River. Data were collected through observations, interviews, photographs, and hand-drawings. The riverside neighborhoods of Belen show architectural qualities that are adaptable to river dynamics through three types of systems: fixed, pile, and floating. In addition, these neighborhoods are located along the course of six natural streams or 'caños' that redirect rainwater and wastewater into the Itaya River. The research shows that the urban configuration of the upper, middle, and lower zones undergoes adaptation processes in their commercial, cultural, and constructive dimensions due to the influence of the Itaya River. This social-spatial configuration is supported by the positive attitude of the residents of the Belen neighborhood toward the Amazonian river dynamics.2