Data for: Late Holocene volcanic and anthropogenic mercury deposition in the western Central Andes (Lake Chungará, Chile)

This file contains the age model, and the mercury (THg), carbon (TC and δ13C), XRF-core scanning and Py-GC/MS analyses used in the manuscript "Late Holocene volcanic and anthropogenic mercury deposition in the western Central Andes (Lake Chungará, Chile)"

Guédron et al STOTEN 2020 Lake Titicaca Hg diagenesis dataset

Geochemical dataset for the manuscript:Enhanced methylmercury accumulation in carbonate sediments and mobilization to the water column in Lake Titicaca (Bolivia)by S. Guédron, S. Audry, D. Acha, S. Bouchet, D. Point, T. Condom, A. Baya, C. Heredia, S. Campillo, A. Groleau, E. Amice and D. Amouroux. published in Science of the Total Environment, 2020Corresponding AuthorAdress: ISTerre, Université Grenoble Alpes, Institut de Recherche pour le Développement (IRD) – UMR 5275 (IRD/UJF/CNRS) – BP 53, F-38041 Grenoble, FranceEmail: [email protected] DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Data base Lake Titicaca lake level

database of the manuscript "Holocene variations in Lake Titicaca water level and their implications for sociopolitical developments in the central Andes" submitted to PNASTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Data for: Late Holocene volcanic and anthropogenic mercury deposition in the western Central Andes (Lake Chungará, Chile)

This file contains the age model, and the mercury (THg), carbon (TC and δ13C), XRF-core scanning and Py-GC/MS analyses used in the manuscript "Late Holocene volcanic and anthropogenic mercury deposition in the western Central Andes (Lake Chungará, Chile)".THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Determination of mercury atmospheric origin in French Guianese soils.

International audienceMercury pollution is a preoccupying environmental problem affecting French Guiana ecosystems. Mercury (Hg) concentrations found in fei-rallitic soils of the dense Guianese forest are high and variable. Natural Hg geochemical background is the result of a long telm accumulation from two sources in the soil, in situ, weathering ofparental material and atmospheric inputs from oceans principally. Abnormally high levels of mercury are related to gold-mining activities. To evaluate the proportion of mercury from weathering processes and from atmospheric inputs, we used a mass balance calculation based on trace elements. This approach reveals that even in areas considered to be natural environments, the proportion of Hg derived from weathering appears to be negligible compared to the atmospheric origin. Soils located close to gold-mining sites are strongly affected by mercury pollution. Pellehatioll and accumulation of atmospheric inputs as well as Hg redistribution in soil profiles depend on the hydrodynamical propeliies, redox conditions and the quality and quantity of carrier phases. Key-words: Mercury, soils, atmospheric inputs, geochemical background, pollution, gold-mining

Determination of mercury atmospheric origin in French Guianese soils

Mercury pollution is a preoccupying environmental problem affecting French Guiana ecosystems. Mercury (Hg) concentrations found in fei-rallitic soils of the dense Guianese forest are high and variable. Natural Hg geochemical background is the result of a long telm accumulation from two sources in the soil, in situ, weathering ofparental material and atmospheric inputs from oceans principally. Abnormally high levels of mercury are related to gold-mining activities. To evaluate the proportion of mercury from weathering processes and from atmospheric inputs, we used a mass balance calculation based on trace elements. This approach reveals that even in areas considered to be natural environments, the proportion of Hg derived from weathering appears to be negligible compared to the atmospheric origin. Soils located close to gold-mining sites are strongly affected by mercury pollution. Pellehatioll and accumulation of atmospheric inputs as well as Hg redistribution in soil profiles depend on the hydrodynamical propeliies, redox conditions and the quality and quantity of carrier phases.
Key-words: Mercury, soils, atmospheric inputs, geochemical background, pollution, gold-mining

Industrial mercury pollution in a mountain valley ::a combined geophysical and geochemical study

Many alpine valleys have inherited strong industrial remnants. Chemical and metallurgical companies were set up in these narrow glacial valleys at the beginning of the industrial era to benefit from cheap labor and hydroelectricity. Regulations concerning solid and liquid waste handling did not exist, and contaminated sediments were often used as soil amendment to improve soil texture, spreading the contamination, which local Authorities have now to deal with. In the present study we report on mercury contamination in the narrow alpine valley known as canton of Valais valley. Waste materials and contaminated sediments were deposited in the valley for many years. An electromagnetic conductivity survey allowed a definitive mapping of the extent of such practices because an EM conductivity contrast was clearly detectable between the added silty-clay material and the natural silty-sand soil. High EM conductivity correlates quite well with high Hg surface soil content. Cores drilled at hotspots and along the canal were analyzed for total mercury, methyl mercury, and core sedimentary features recorded. While up to 70 cm thick, dredged, Hg-contaminated material was found to lay above the original sandy soil in housing areas, the mercury contamination extends down to 1.5 m depth, i.e. down to the water table, probably caused by the high sediment material organic content (OC), and OC-Hg enhanced transport. Methylation reductive conditions were observed, together with high MeHg relative abundance ([MeHg]/ [HgT] > 0.1%), in two environments, namely the zone of fluctuating water table and the canal water/sediment interface. Groundwater quality was not impacted, because of large groundwater fluxes observed in these glacial alpine valleys

Cycle du mercure et du methylmercure entre les sédiments et la colonne d'eau au cours d'une marée dans la lagune de Venise (Italie)

International audienceThe sediment of Venice Lagoon regularly undergoes complex redistribution due to tidal forcing, which affects the cycling of contaminants such asmercury (Hg) between the sediment and thewater column. We examined the dis-tribution of total Hg (THg) and monomethylmercury (MMHg) in the water column, sediment and pore-water at two sites: VE1 (located in a depositional area adjacent to salt marshes) and VE2 corresponding to a moderately erosive, open area. We obtained instantaneous (using cores and micro-needle samplers) and time-integrated (using peepers) concentrations of the two mercury species in both dissolved and particulate forms. THg and MMHg concentrations were higher in the sediments at site VE1 (621.9±213.7 ng g−1 and 1.25±0.63 ng g−1 for THg and MMHg, respectively) than in those of the site VE2 (386.9±92.7 ng g−1 and 0.53±0.30 ng g−1). Hg concentrations in sedimentswere positively correlatedwith silts and organicmatter content. Over two tidal cycles, the concentrations of THg and MMHg varied with the evolution of the tides. During the tidal !ooding, both THg and MMHg peaked at the sediment–water interface and a moderate increase of dissolved MMHg was also ob- served in thewater column. These !uctuationswere observed during both tides and are suggestively related to ad-vection of mercury species from sur"cial sediment pore-water to the water column and to desorption from suspended particles. The short-term increase in MMHg concentrations can result from in situ production, release from organicmatter degradation, or from oxidative dissolution of redox-sensitive sul"de minerals and iron oxide reduction by micro-organisms; the two latter mechanisms being favored by redox oscillations in the surface sed-iment layers due to the tidal forcing. The decrease of both dissolved THg and MMHg concentrations at the sedi-ment–water interface after high tide was attributed to a rapid adsorption onto particles. THg concentrations on suspended particles showed little variations during the tidal cycle with a minor peak at tide maximum, while MMHg concentrations on suspended particles slightly increased during ebb tide. MMHg concentrations on sus-pended particleswere double than those in surface sediments, suggesting that tidal !ushingmay enhance dispers-al of particle bound MMHg throughout the lagoon

Archeoseismology in Machu Picchu, Paleoseismology and Lacustrine records in Cuzco region as key interdisciplinary approaches for intraplate deformation characterization on the Andean Altiplano

International audienc