Abstract Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis.

Resumen Introducción: Las arqueas metanogénicas (MA) participan en la mineralización anaerobia de la materia orgánica en sedimentos de manglar, su actividad está relacionada con el calentamiento atmosférico por la producción de metano; diversas variables ambientales pueden influir en la dinámica metanogénica y la producción de metano en estos sedimentos. Objetivo: Analizar, mediante técnicas dependientes de cultivo, la abundancia de las arqueas metanógenas viables (AMV) y la producción de metano en diferentes épocas climáticas en los sedimentos del manglar El Morro-La Mancha, Veracruz, Golfo de México. Métodos: De mayo a noviembre 2019, siguiendo un transecto de salinidad, se recolectaron sedimentos del manglar del Morro-La Mancha, en tres localidades, abarcando tres diferentes épocas climáticas, secas (mayo), lluvias (octubre) y nortes (noviembre) (N = 9), cuantificándose la abundancia de las AMV mediante la técnica del Número Más Probable (NMP) con acetato y metanol como substratos; la influencia de los sulfatos en la producción de metano a partir de acetato en microcosmos, se analizó por cromatografía de gases y se evaluaron las variables químicas de salinidad, pH, Eh, carbohidratos, contenido orgánico y carbonatos en los sedimentos. Resultados: Se determinó una abundancia de AMV de 102 a 108 NMP/g de sedimento húmedo, superior a la reportada en otros estudios, dicha abundancia se incrementó cuando se utilizó metanol (104-108 NMP/g sedimento) como sustrato, en comparación con el acetato (102-105 NMP/g sedimento); la producción de metano en los microcosmos aumentó en condiciones libres de sulfatos (29.78-929.75 nmol CH4/mes) y en los sedimentos de la temporada de lluvias. Conclusión: Se destaca la influencia de las condiciones químicas de los sedimentos del manglar sobre la dinámica metanógena, determinándose que, en la temporada de lluvias, una disminución de la salinidad, Eh más electronegativos y el incremento de las fracciones orgánicas favorecieron la metanogénesis.

Abstract The present study addresses the identification and estimation of siliceous diagnostic microremains of maize (Zea mays) in archaeological contexts of North-east Argentina, contributing to the understanding of pre-Hispanic agricultural expansion in the region. The methodology involved the application of processing protocols for current and archaeological plants and sediments, establishing correlations between samples. The result of this process allowed us to calculate the number of cross-shaped morphotypes per gram of dry material in contemporary maize leaves, key information to estimate the relative abundance of diagnostic elements in archaeological cultivation areas, providing an estimation index applicable to other contexts. This analysis not only reveals the ubiquity of Zea mays at sites, but also provides a measure to estimate the approximate volume of its production at archaeological sites, addressing outstanding questions about exchange routes, horticultural modalities and needs of human groups in the past.

Resumen El presente estudio aborda la identificación y estimación de microrrestos silíceos diagnósticos de maíz (Zea mays) en plantas actuales y sitios arqueológicos del Noreste argentino, contribuyendo a la comprensión de la expansión agrícola prehispánica en la región. La metodología involucró la aplicación de protocolos de procesamiento para plantas y sedimentos actuales y arqueológicos, estableciendo correlaciones entre las muestras. El resultado de este proceso permitió calcular la cantidad de morfotipos en forma de cruz por gramo de material seco en hojas de maíz actual, información clave para estimar la abundancia relativa de elementos diagnósticos en áreas de cultivo arqueológicas, proporcionando un índice de estimación aplicable a otros contextos. Este análisis no solo revela la ubicuidad de Zea mays en los sitios, sino que también ofrece una medida para calcular el volumen aproximado de su producción en sitios arqueológicos, abordando preguntas pendientes sobre rutas de intercambio, modalidades hortícolas y necesidades y demandas de los grupos humanos en el pasado.

ABSTRACT This work investigates the potentiality of the 2D electrical resistivity tomography method to delineate an altered intrusive rock domain. The detection and characterization of such altered domains are crucial to understanding local hydrogeological conditions. Here, the target is the San Luis area, located in the northern part of the Estibaná River watershed, within the Los Santos Province in the central region of the Isthmus of Panama. First, a detailed geological survey was carried out to better constrain the tectonic structures. Then, two geological sections were developed based on two 2D electrical resistivity tomographies. A geoelectrical simulation process was conducted in both sections to set theoretical models whose model responses (synthetic field data set) would be consistent with the observations. After appropriate selection of the inversion parameters by using the Boundless Electrical Resistivity Tomography (BERT) code, the observations were processed, resulting in low calculation errors (χ2 < 0.51). Based on the superficial geological information and the results of the geophysical modelling, two profiles were established, depicting the lateral and in-depth distribution of rocks and sediments. The limit of the Ocú-Parita fault zone was identified as well. The results of the 2D inversion of the synthetic data, obtained with the established theoretical models, are consistent with the 2D inversion of the observations. Electrical resistivity tomography studies can be useful in establishing groundwater management models, particularly in areas that experience severe water scarcity during the dry season.

RESUMEN Este trabajo investiga la capacidad del método de tomografía de resistividad eléctrica 2D para delinear un dominio de roca intrusiva alterada. La detección y caracterización de este tipo de intrusivos juega un papel importante en esclarecer el contexto hidrogeológico local. La zona de estudio corresponde al área de San Luis, ubicada en la parte norte de la cuenca del río Estibaná, provincia de Los Santos, región central del istmo de Panamá. Para reconocer las estructuras tectónicas de la zona, se realizó primero un levantamiento geológico superficial de detalle. Posteriormente, se efectuaron dos tomografías de resistividad eléctrica 2D a fin de confeccionar dos secciones geológicas. Un proceso de simulación geoeléctrica fue llevado a cabo en ambas secciones para establecer modelos teóricos cuyas respuestas (conjunto de datos de campo sintéticos) fuesen acordes con las observaciones. Posterior a la selección apropiada de los parámetros de inversión mediante el código BERT (Boundless Electrical Resistivity Tomography), las observaciones fueron procesadas, obteniéndose errores de cálculo bajos (χ2 < 0,51). Al combinar la información geológica de superficie y los resultados del modelado geofísico, se crearon dos perfiles geológicos donde es posible observar la distribución lateral y en profundidad de rocas y sedimentos, así como el límite de la zona de falla Ocú-Parita. Los resultados de la inversión 2D de los datos sintéticos obtenidos mediante los modelos teóricos establecidos concuerdan con aquellos de la inversión 2D de las observaciones. Estudios de tomografía de resistividad eléctrica pueden ser útiles en proporcionar modelos de gestión de agua subterránea, particularmente en áreas que experimentan escasez hídrica severa durante la temporada seca.

ABSTRACT This contribution presents the study of an Ordovician subaqueous felsic succession, formed by the ~400 m-thick Upper Member of the Cordón de Lila Complex (CISL), northern Chile. From bottom to top, the succession starts with two dacitic sills that intruded into the sediments of the lowermost part of the Upper Member. Then, it is followed by a thick sedimentary deposit, two rhyolitic lavas, a volcanoclastic felsic breccia with pyroclastic clasts, and ends with a red rhyolitic lava. The first rhyolitic lava shows centimetric to metric folds with a north-northwestern vergence, evidence of flow in that direction. In the volcanoclastic breccia, an abundant pumice-and-fiamme-rich green matrix wraps around lithic clasts, giving the rock an eutaxitic texture at the outcrop scale. This matrix and texture evidence is characteristic of hot pyroclastic flows deposited under subaqueous conditions. The described section of the breccia is formed by four coarsening-up sequences, reflecting respectively four pulses of building up energy. The lack of internal erosional features points to a single and continuous explosive eruption. An accidental granite clast in the upper part of the breccia suggests a connection with a granitic body, possibly the Pingo-Pingo monzogranite. The geochemical character of the felsic succession is calc-alkaline. The tectonic setting diagram shows a within-plate setting for the succession. This suggests a shift from the arc position inferred for the Lower Member of the CISL to a forearc continental setting for the Upper Member of the CISL.

RESUMEN Este trabajo presenta una sucesión subacuática félsica ordovícica, formada por el miembro superior del Complejo ígneo-sedimentario del Cordón de Lila (CISL), el que posee un espesor de ~400 m. De base a techo, la sucesión incluye dos filones-manto dacíticos, intruidos en sedimentos de la parte inferior de dicho miembro. Luego presenta un intervalo de sedimentitas, dos lavas riolíticas y una brecha volcanoclástica félsica con clastos piroclásticos. La secuencia finaliza con una lava riolítica rojiza. El primer flujo de lava riolítica contiene pliegues métricos a centimétricos con vergencia hacia el nornoroeste, lo que indica un flujo en ese sentido. La brecha tiene una abundante matriz verdosa formada por fiamme y pómez soldadas que rodean a los clastos líticos, y otorgan a la brecha una conspicua textura eutaxítica. El tipo de matriz y la textura observadas son características de flujos piroclásticos calientes depositados en ambientes submarinos. La sección descrita de la brecha puede dividirse en cuatro secuencias granocrecientes, las cuales reflejan, respectivamente, cuatro pulsos de energía creciente. La ausencia de discontinuidades internas apunta a una única erupción explosiva. La presencia de un clasto accidental de granito en la brecha sugiere una conexión con un intrusivo granítico en profundidad, posiblemente el monzogranito Pingo-Pingo. La afinidad geoquímica de la sucesión es calcoalcalina. En el diagrama de ambientes tectónicos, las volcanitas del miembro superior caen dentro del campo de intraplaca. Esto sugiere un cambio desde un ambiente de arco volcánico para el miembro inferior del CISL a una posición de antearco continental para el miembro superior del CISL.

ABSTRACT The aim of this study was to assess the deposition rates (Td) of mineral aeolian sediments in a forest patch in the semiarid Pampas agroecosystem and to analyze the seasonal variability of such deposition. The average Td was 520.15 kg ha-1 year-1 with high interannual variability. In spring-summer, Td was higher than in autumn-winter. Air temperature and average maximum wind speed influenced Td more significantly. However, the soil cover and management of the agricultural fields surrounding the forest would determine the production of sediment from wind erosion and consequent deposition within the forest. These results show the importance of maintaining forest patches within the agricultural matrix in the semi-arid environment, since they retain eolian sediments that would eventually be deposited on the forest soil, minimizing the negative impacts of wind erosion processes on these ecosystems.

RESUMEN El objetivo de este estudio fue determinar las tasas de sedimentación (Td) de sedimentos eólicos minerales en un parche de bosque del agroecosistema del semiárido pampeano y analizar la variabilidad estacional de dicha sedimentación. La Td media fue 520,15 kg ha-1 año-1 con alta variabilidad interanual. En primavera-verano, Td fue superior que en otoño-invierno. La temperatura del aire y velocidad media máxima del viento influenciaron de forma más significativa a Td. Sin embargo, la cobertura del suelo y el manejo de los campos agrícolas que rodean al bosque determinarían la producción de sedimentos a partir de la erosión eólica y consecuente sedimentación dentro del bosque. Estos resultados muestran la importancia de mantener los parches de bosques dentro de la matriz agrícola en el semiárido, los cuales retienen sedimentos eólicos que finalmente se depositarían en el suelo forestal, minimizando los impactos negativos que los procesos de erosión eólica tienen en estos ecosistemas.

Abstract: The study was conducted at the Jalpan de Serra dam, Querétaro, Mexico. In a mountain watershed with a history of artisanal mining activity in the upper part, runoff feeds the reservoir, transporting mining tailings. The Jalpan dam has been used for drinking water supply, agricultural irrigation activities and recreational purposes as a Ramsar site. The reason for the study has been the relevance and social impact of the reservoir sediments as a source of diffuse pollution. The objective was to determine the concentration of arsenic, cadmium and lead in the sediment and to evaluate the level of risk to human health and the environment. The methodology consists of the analysis by atomic absorption carried out in three sites sampled in the superficial layer of 10 cm depth, samples obtained with a PVC tube of 7 cm diameter, identified, preserved for transfer and digested with nitric acid. The results show mean arsenic concentrations of 4.278 mg/kg, cadmium 0.323 mg/kg and lead 4.873 mg/kg. In conclusion, the sediment analyzed does not represent a risk to human health or the environment of the reservoir according to NOM-147-SEMARNAT/SSA1-2004. This investigation demonstrates the lack of a policy or standard that establishes permissible limits for heavy metals in sediment.

Resumen: El estudio ha sido realizado en la presa Jalpan de Serra, Querétaro, México. En una cuenca de montaña con antecedentes de actividad minera artesanal en la parte alta, la escorrentía alimenta el embalse, transportando relaves mineros. La presa Jalpan se ha empleado para abastecimiento de agua de consumo humano, actividades de riego agrícola y fines recreativos como sitio Ramsar. El motivo de estudio ha sido la relevancia e impacto social que tienen los sedimentos del embalse como fuente de contaminación difusa. El objetivo ha sido conocer la concentración de arsénico, cadmio y plomo en el sedimento y evaluar el nivel de riesgo para la salud humana y del ambiente. La metodología consiste en el análisis por absorción atómica realizada en tres sitios muestreados en la capa superficial de 10 cm de profundidad, muestras obtenidas con un tubo de PVC de 7 cm de diámetro, identificadas, conservadas para su traslado y digeridas con ácido nítrico. Los resultados muestran concentraciones medias en arsénico de 4.278 mg/kg, cadmio 0.323 mg/kg y plomo 4.873 mg/kg. En conclusión, el sedimento analizado no representa riesgo para la salud humana o entorno del embalse según la norma NOM-147-SEMARNAT/SSA1-2004. Esta investigación evidencia la falta de una política o norma que establezca los límites permisibles de metales pesados en sedimentos.

RESUMEN Las investigaciones sobre cianobacterias bentónicas en reservorios de alta montaña en regiones tropicales aún son limitadas, debido a su complejidad y vacíos de conocimiento en relación con su ecología. Este estudio tuvo como objetivo explorar la composición, diversidad y potencial tóxico de estas cianobacterias en sedimentos superiores de dos embalses colombianos, empleando múltiples metodologías, como experimentos de germinación para evaluar su presencia y viabilidad en sedimentos, ensayos de ELISA competitivo para cuantificar toxinas en cultivo, análisis de Unidades Taxonómicas Operativas (OTUs) a partir de submuestras de los cultivos para evaluar su diversidad y riqueza entre los diferentes phylum procarióticos, y análisis filogenético de cianobacterias cultivables. Se confirmó la presencia de poblaciones viables de cianobacterias en los sedimentos mediante mediciones de clorofila-a y la identificación microscópica demostró su capacidad de crecimiento en condiciones controladas de laboratorio. A pesar de los bajos niveles de microcistina en cultivo, la detección previa de genes mcy en muestras directas de sedimento, sugiere un potencial tóxico en las cianobacterias presentes. El análisis de la comunidad reveló una notable diversidad microbiana en los sedimentos de ambos embalses, con una mayor abundancia relativa de cianobacterias en comparación con otros phylum procarióticos. Estos hallazgos respaldan la hipótesis de que los sedimentos superficiales desempeñan un papel fundamental como depósito de cianobacterias que pueden plantear riesgos inherentes a la salud del ecosistema. En conclusión, esta investigación subraya la necesidad de realizar más estudios para lograr una comprensión holística de la dinámica de las cianobacterias bentónicas en reservorios tropicales de alta montaña.

ABSTRACT Benthic cyanobacteria research in high mountain reservoirs remains limited, mainly due to their complexity and knowledge gaps that persist in relation to their ecology in tropical regions. This study aimed to explore the composition, diversity, and toxic potential of cyanobacterial in the upper sediment of two Colombian reservoirs. Our investigation involved multiple methodologies, such as germination experiments, that allowed us to assess the presence and viability of cyanobacteria in upper sediment samples, while the competitive ELISA assay allowed for the quantification of toxins within the cultures. The molecular analysis of Operational Taxonomic Units (OTUs) from subsamples of sediment cultures focused on evaluating cyanobacterial diversity and richness among prokaryotic phyla, and the Phylogenetic analysis of culturable cyanobacteria. Chlorophyll-a measurements confirmed the presence of viable populations in sediment cultures, while microscopic identification demonstrated the growth capacity of cyanobacteria from the orders Nostocales, Chroococcales, Oscillatoriales, and Synechococcales under controlled laboratory conditions. Despite low microcystin levels in culture, the prior detection of mcy genes in direct sediment samples suggests a possible toxic potential of cyanobacterial inhabiting the upper sediments. Community analysis, based on the OTUs abundance, revealed a notably diverse microbial community in both reservoir sediments, with a higher relative abundance of cyanobacteria compared to other prokaryotic phyla. These findings support the hypothesis that surface sediments play a fundamental role as a repository for cyanobacteria that may pose inherent risks to ecosystem health. In conclusion, this research underscores the necessity of further studies to achieve a holistic comprehension of benthic cyanobacteria dynamics in high-mountain tropical reservoirs.

Abstract The sustainability of water use in agriculture is very important, and to achieve this, proper management of surface water resources is required, which, in small basins, depends on good measurement of flow rate data. This work analyzes the hydraulic performance of three proposed modified long-throated flumes with a 10% slope supercritical channel by using the WinFlume® v.1.06 software for a maximum flow of 50 L s-1, for clean water and in conditions in which the cross section of the inlet was modified by sediments. Hydraulic simulations were performed for triangular, rectangular, and trapezoidal cross sections in the throat and the supercritical channel by using the Iber® v.2.5.2 software to compare the pattern of the WinFlume® gauging curve with the results of Iber®; the difference between both gauging curves was a maximum error of 3% in the three cross-sectional areas. For hydraulic simulation in the supercritical modified cross-sectional area for clean flow water and sediment flow water, data located at half the total length of the supercritical channel were taken. Variations in flow depth assuming sedimentation were negligible, and it was found that the water profile in the supercritical channel was not affected, so it can be used as an indicator. In addition, it was observed that the best cross-sectional area for the channel was the rectangular one with a maximum of 0.9997 R2 for the flow rate curve (Q-h).

Resumen La sostenibilidad del uso del agua en la agricultura es muy importante, y para lograrlo se requiere de una gestión adecuada de los recursos hídricos superficiales, que en cuencas pequeñas depende de una buena medición de los datos de caudales. Este trabajo analiza el desempeño hidráulico de tres aforadores modificados de garganta larga propuestos con un canal supercrítico de pendiente de 10%, utilizando el software WinFlume® v.1.06 para un flujo máximo de 50 L s-1, para agua limpia y en condiciones en las que la sección transversal de la entrada fue modificada por sedimentos. Se realizaron simulaciones hidráulicas para secciones transversales triangulares, rectangulares y trapeciales en la garganta y el canal supercrítico, empleando el software Iber® v.2.5.2, para comparar el patrón de la curva de aforo de WinFlume® con los resultados de Iber®, la diferencia entre ambas curvas de aforo fue de un error máximo de 3% en las tres áreas transversales. Para la simulación hidráulica en el área de sección transversal modificada supercrítica para agua de flujo limpio y agua de flujo con sedimentos, se tomaron datos situados a la mitad del largo total del canal supercrítico. Las variaciones de la profundidad del flujo suponiendo sedimentación fueron insignificantes, y se encontró que el perfil del agua en el canal supercrítico no se vio afectado, por lo que puede usarse como indicador. Además, se observó que la mejor área de sección transversal para el canal fue la rectangular con un máximo de 0.9997 R2 para la curva de caudal (Q-h).

ABSTRACT A comprehensive tectono-stratigraphic and sedimentological investigation of Early to Middle Devonian rocks was conducted in the southern Floresta Massif and adjacent regions in the Northern Andes of Colombia. A substantially reduced thickness of the Floresta Formation compared to prior studies is suggested here, attributable to pronounced stratal deformation and the prevalence of recumbent folds throughout the area. The deformation in the Floresta Formation manifests as atypical recumbent folds, diverging from the structural behavior observed in the underlying and overlying strata of the El Tibet and Cuche formations respectively, which exhibit minimal deformation. Our findings also reveal that the Floresta Formation accumulated under shallow-water platform conditions, subject to eustatic sea-level fluctuations. This resulted in distinct episodes of carbonate and siliciclastic deposition, with terrigenous sediments sourced from continental origins, potentially encompassing a combination of cratonic areas and uplifted blocks. The identification of a plausible stage of carbonate silicification signifies a post-diagenetic transformation. The sedimentary rocks of the Floresta Formation reached the upper epizone conditions, in proximity to the transition between the epizone and the upper anchizone, which suggests a maximum depth and temperature of ~5-7 km and ~300 °C, respectively. This contribution provides new insights into the geological history of the region, emphasizing the importance of scrutinizing Early to Middle Devonian rocks within the broader geological context of the Northern Andes.

RESUMEN Este trabajo presenta una exhaustiva investigación tectono-estratigráfica y sedimentológica de las rocas del Devónico temprano a Medio en el sur del Macizo de Floresta y regiones adyacentes, Andes del Norte, Colombia. Se sugiere un espesor sustancialmente reducido para la Formación Floresta en comparación con estudios previos, atribuible a una deformación pronunciada de los estratos y a la prevalencia de pliegues recumbentes en toda el área. La deformación en la Formación Floresta se manifiesta mediante pliegues recumbentes atípicos, a diferencia del comportamiento estructural observado en los estratos subyacentes y sobreyacentes de las formaciones El Tíbet y Cuche, respectivamente, que muestran una deformación mínima. Se revela también que la Formación Floresta se acumuló en condiciones de plataforma de aguas someras, sujeta a fluctuaciones eustáticas del nivel del mar. Esto resultó en variados episodios de depositación carbonática y siliciclástica, con aportes de sedimentos terrígenos provenientes de fuentes continentales, los que posiblemente abarcaron una combinación de áreas cratónicas y bloques levantados. La identificación de una posible etapa de silicificación carbonática indica una transformación postdiagenética. Las rocas sedimentarias de la Formación Floresta alcanzaron las condiciones de la epizona superior, en proximidad a la transición entre la epizona y la anquizona superior, lo cual sugiere una profundidad y temperatura máximas de ~5-7 km y ~300 °C, respectivamente. Esta investigación aporta nueva información acerca de la compleja historia geológica de la región, enfatizando la importancia de examinar las rocas del Devónico Temprano a Medio en el contexto geológico más amplio de los Andes del Norte.

Abstract Mangroves buffer metals transfer to coastal areas though strong accumulation in sediments making necessary to investigate metals’ bioavailability to plants at the rhizosphere. This work evaluates the effect of mangrove root activity, through iron plaque formation, on the mobility of iron and copper its influence on metals’ uptake, and translocation through simultaneous histochemical analysis. The Fe2+ and Fe3+ contents in porewaters ranged from 0.02 to 0.11 µM and 1.0 to 18.3 µg.l-1, respectively, whereas Cu concentrations were below the method’s detection limit (<0.1 µM). In sediments, metal concentrations ranged from 12,800 to 39,500 µg.g-1 for total Fe and from 10 to 24 µg.g-1 for Cu. In iron plaques, Cu concentrations ranged from 1.0 to 160 µg.g-1, and from 19.4 to 316 µg.g-1 in roots. Fe concentrations were between 605 to 36,000 µg.g-1 in the iron plaques and from 2,100 to 62,400 µg.g-1 in roots. Histochemical characterization showed Fe3+ predominance at the tip of roots and Fe2+ in more internal tissues. A. schaueriana showed significant amounts of Fe in pneumatophores and evident translocation of this metal to leaves and excretion through salt glands. Iron plaques formation was essential to the Fe and Cu regulation and translocation in tissues of mangrove plants. rhizosphere activity uptake analysis Fe2 Fe3 002 0 02 0.0 011 11 0.1 1 1. 183 18 3 18. µg.l1, µgl1 µgl µg.l 1, µg l µg.l-1 respectively methods method s <0.1 01 (<0. µM. . µM) 12800 12 800 12,80 39500 39 500 39,50 µg.g1 µgg1 µgg µg.g g µg.g- 2 16 µg.g1, 194 19 4 19. 31 60 36000 36 000 36,00 2100 100 2,10 62400 62 400 62,40 A glands 00 0. l1 µg.l1 µg.l- <0. (<0 1280 80 12,8 3950 50 39,5 g1 6 3600 36,0 210 2,1 6240 40 62,4 <0 (< 128 8 12, 395 5 39, 360 36, 21 2, 624 62, < (

ABSTRACT On January 2022, the Carmo River (a tributary of the Doce River) was affected by an extreme hydrological event, with 50-yr return interval. This event was 50% higher than that associated to one of the largest tailing dam failures ever reported that took place in the Gualaxo do Norte River. This delivered to Doce River, through the Carmo River, in a Y-shaped confluence, the contaminated tailing slurry. In order to understand the role of tributaries in the recovery of the Doce River, 2D hydrodynamic and 2D sediment transport models were applied at the confluence of the Carmo River with the Piranga River. Our results, based on hydraulic modeling, remote sensing, and in-situ measurements, indicated that significant amounts of sediments were trapped on the riverbanks and stone banks, making this confluence an important site for the retention of contaminated sediments, influencing sediment budgets and downstream water quality. Therefore, this confluence deserves special attention from water engineering in order to prevent the sediments retained in this area from being transported downstream during extreme events in the coming years. These results can contribute to decision-making, to identify reaches with greater susceptibility to erosion and sediment deposition and to plan the restoration of these rivers. 2022 50yr yr 50 interval Yshaped Y shaped slurry D modeling sensing insitu situ measurements banks quality Therefore years decisionmaking, decisionmaking decision making, decision-making rivers 202 5 20 2

RESUMO Em janeiro de 2022, o Rio Carmo (um afluente do Rio Doce) foi afetado por um evento hidrológico extremo, com um tempo de retorno de 50 anos. Esse evento foi 50% mais intenso do que o associado a uma das maiores falhas de barragem de rejeitos já registradas, que ocorreu neste mesmo rio. Isso resultou no despejo de rejeitos de mineração contaminados no Rio Doce, por meio do Rio Carmo, em uma confluência em forma de Y. Com objetivo de entender a função dos afluentes na recuperação do rio Doce, foram realizadas simulações hidrodinâmicas e de transporte de sedimentos, a partir da versão bidimensional do modelo HEC-RAS, na confluência do rio do Carmo com o rio Piranga. Nossos resultados, com base em modelagem numérica, sensoriamento remoto e medições in situ, apontaram que grandes quantidades de sedimentos foram retidas nas margens do rio e nos bancos de pedra, o que torna esta confluência um local importante para a retenção de sedimentos contaminados, com influências significativas para a qualidade de água a jusante. Sendo assim, essa confluência merece uma atenção especial da engenharia Hídrica a fim de evitar que os sedimentos retidos nesta área sejam transportados a jusante durante os eventos extremos nos próximos anos. Esses resultados podem contribuir para a tomada de decisões, para identificação de trechos com maior suscetibilidade a erosão e deposição de sedimento e para planejamento da restauração desses rios. 2022 Doce extremo 5 anos registradas Y HECRAS, HECRAS HEC RAS, RAS HEC-RAS Piranga numérica situ pedra assim decisões rios 202 20 2

ABSTRACT Land sharing (Lsh) and land sparing (Lsp) are land use strategies that present different potentials for achieving multiple objectives in the land use planning, such as biodiversity conservation and provision of ecosystem services. Through a case study in the Saltinho Watershed in Imbaú/PR, we evaluated the extent to which the application of each of these strategies in landscape planning can contribute to the conservation of biodiversity and maintenance of water quality. The analysis was performed based on the comparison between three scenarios: native vegetation cover in 2008, compliance with the law nº. 12,651/12 and watershed-scale vegetation planning, in accordance with the precepts of the Lsh and Lsp. For each scenario, landscape metrics and sediment production were calculated, using a vector-based analysis tool (V-LATE) and an ecosystem service management tool (InVEST). In the studied models, the results indicate that the application of Lsh and Lsp contributed to the improvement of landscape metrics and to the reduction of the quantity of sediments exported to water courses, which could represent positive effects for biodiversity and water quality in the watershed. However, these effects were not directly proportional, according to the transition of the analyzed scenarios. Therefore, the exploration of different land use configurations and proportions between these strategies can contribute to identify potential thresholds for biodiversity conservation and provision of ecosystem services, and, in addition, assist in land use planning for sustainable agricultural landscapes. (Lsh (Lsp services ImbaúPR Imbaú PR Imbaú/PR scenarios 2008 nº 1265112 12 651 12,651/1 watershedscale watershed scale scenario calculated vectorbased vector VLATE V LATE (V-LATE InVEST. InVEST . (InVEST) models courses However proportional Therefore addition landscapes 200 126511 1 65 12,651/ (InVEST 20 12651 6 12,651 2 1265 12,65 126 12,6 12,

RESUMO Land sharing (Lsh) e land sparing (Lsp) são estratégias de uso do solo que apresentam diferentes potenciais para o alcance de múltiplos objetivos no processo de planejamento da paisagem, como a conservação da biodiversidade e a provisão de serviços ecossistêmicos. Por meio da realização de um estudo de caso na bacia hidrográfica do rio Saltinho em Imbaú/PR, buscou-se avaliar em que medida a aplicação dessas estratégias contribui para a conservação da biodiversidade e a manutenção da qualidade da água na bacia. A análise foi realizada a partir da comparação entre três cenários: cobertura de vegetação nativa em 2008, conformidade com a Lei n.º 12.651/12 e planejamento da vegetação na escala da bacia, de acordo com os preceitos do Lsh e do Lsp. Para cada cenário, foram calculadas as métricas de paisagem e a produção de sedimentos, com o uso de uma ferramenta de análise baseada em vetores (V-LATE) e uma ferramenta de gestão de serviços ecossistêmicos (InVEST). Nos modelos estudados, os resultados indicam que a aplicação do Lsh e Lsp contribuiu para a melhoria de métricas de paisagem e para a redução da quantidade de sedimentos exportados aos corpos hídricos, o que poderia representar efeitos positivos para a biodiversidade e qualidade da água na bacia. No entanto, esses efeitos não se mostraram diretamente proporcionais, conforme transição dos cenários analisados. Dessa forma, a exploração de diferentes configurações e proporções de usos do solo entre essas estratégias pode auxiliar a identificação de potenciais limiares para conservação da biodiversidade e provisão de serviços ecossistêmicos, e, além disso, no planejamento de paisagens agrícolas sustentáveis. (Lsh (Lsp ImbaúPR Imbaú PR Imbaú/PR buscouse buscou 2008 nº n º 1265112 12 651 12.651/1 cenário VLATE V LATE (V-LATE InVEST. InVEST . (InVEST) estudados hídricos entanto proporcionais analisados forma disso sustentáveis 200 126511 1 65 12.651/ (InVEST 20 12651 6 12.651 2 1265 12.65 126 12.6 12.

Abstract The Quadrilátero Ferrífero (QF) is a globally known region for its world-class metallic deposits. Although its Precambrian units have been vastly studied since the 1960s due to economic importance, the Cenozoic geological record represents an upcoming subject of interest. The occurrence of Cenozoic sedimentary deposits has been noticed since the end of the 19th century, but most of them are not yet fully characterized. This paper brings a complete description, mapping, 3D modeling, and simulations of the sedimentary deposit named Bandeira Basin, Serra do Tamanduá, QF. Based on field data, such as mapping and drill core database analysis, three drill cores were selected for further investigation and detailed description. The Bandeira Basin can be characterized and subdivided into three units: Unit A: found only in the southeast area and shows exclusively sediments from the Nova Lima Group; Unit B: intermediate unit that occurs in central and southeast areas, with Rio das Velhas Supergroup as a possible source of the sedimentary material; and Unit C: occurs at the top, and it is essentially colluvial deposits from Minas Supergroup units. The contacts between units are abrupt or erosive, recording successive deposition stages. The basin is thicker on its central and southwest ends and thinner on the east and north, where part of the basement outcrops. Cenozoic tectonic events were probably active in this area, controlling the sedimentary processes, with the NW-SE and NE-SW lineaments reactivated, triggering sediment deposition and migration to the deepest spot of the basin. These sediments were 3D modeled in Leapfrog Geo, the visualization of any given region of interest, in the modeled scale. This methodology allowed an assertive characterization of sedimentary filling and could be applied to other basins. This comprehension is important because these sediments are used indirectly or directly in civil projects. QF (QF worldclass world class s importance interest th century description D modeling Tamanduá data analysis A Group B areas material C top erosive stages north outcrops processes NWSE NW SE NESW NE SW reactivated Geo scale basins projects

Abstract This study aimed to investigate the biogenic composition of calcium carbonate (CaCO 3) in pelagic sediments in the Santos Basin over the past 140,000 years. The content and composition of CaCO 3 in different sediment fractions were evaluated, including the bulk sample, coarse fraction (foraminifera), medium fraction (juvenile foraminifera and fragments), and fine fraction (nannofossils), to determine the contribution of each fraction to the carbonated sediment composition. We found that variations in CaCO 3 levels were closely linked to glacial and interglacial periods, with higher values during interglacial periods and lower values during glacial periods. The main factor controlling the variation in CaCO 3 was dissolution, which was mainly linked to the influx of more corrosive southern water masses. Fluctuations in CaCO 3 levels were influenced by variations in productivity and dilution caused by terrigenous sediments. Nevertheless, it is noteworthy that both processes held a relatively minor impact compared to dissolution. Productivity primarily contributed to increased dissolution rates. During periods of low sea levels, dilution by terrigenous sediments became significant (similarly, the influence of the La Plata River plume was notable). However, due to the limited presence of riverine supply in the study area, which contributes directly to major dilution influences, fluctuations in terrigenous materials were considered of lesser magnitude than those caused by dissolution. The nannofossils were found to be the largest contributor to the total CaCO 3 composition, as they were the fraction least affected by the dissolution process. Overall, our results provide insights into the factors influencing CaCO 3 accumulation in marine sediments and can be used as a tool to determine changes between climatic cycles over time. 140000 140 000 140,00 years evaluated sample foraminifera, , (foraminifera) juvenile fragments, fragments fragments) nannofossils, (nannofossils) masses Nevertheless rates similarly, similarly (similarly notable. notable . notable) However area influences process Overall time 14000 14 00 140,0 (foraminifera (nannofossils 1400 1 0 140,

Abstract Biomarkers of environmental contamination have been frequently used in the assessment of marine ecosystem quality because they provide quantitative measures of biological changes in organisms exposed to pollutants such as hydrocarbons from oil spills. Polychaetes have been tested as sentinel organisms of marine environmental health because they are abundant taxa of benthic assemblages and their sedentary lifestyle ensures chronic exposure to toxins in impacted areas. In this study, we evaluated whether the polychaete Scolelepis goodbodyi can be used as a reliable sentinel species for exposure to polycyclic aromatic hydrocarbons (PAHs) from an experimental diesel spill in a dissipative sand beach in the Southern Atlantic. The design used in this study comprised replicated control and diesel impact sites sampled four times (one, two, four and seven days) before and after the impact. Total PAH levels reached 114.0 ng g -1 in the impact site one day after the diesel spill; however, the pattern of biomarker responses in S. goodbodyi was primarily influenced by spatial variation rather than being attributed to the simulated diesel spill. The apparent absence of a contaminating effect may be linked to the low levels of the toxins retained in the sediment after the spill was simulated to elicit a response or to the presence of an efficient repair system within the organism. Furthermore, the sediments tested in this study, composed of sandy fractions, had a low capacity to concentrate PAHs after the simulated diesel spill, which may have contributed to the low significant changes in their biomarker activities. Based on our results, further studies testing other Polychaeta species and simulating oil spills in sedimentary environments composed of fine sediments such as salt marshes and mangroves may help produce evidence on more effective biomarker responses in these organisms. areas (PAHs Atlantic one, (one two days 1140 114 0 114. 1 - however S organism Furthermore fractions activities results 11