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A volcanic dome complex of Miocene age hosts the In-bearing Ánimas–Chocaya–Siete Suyos district in SW Bolivia. Ore mineralization occurs as banded and massive infillings in sub-vertical, NE-SW striking veins. In this article, a detailed petrographic study is combined with in situ mineral geochemistry determinations in ore from the Arturo, Chorro and Diez veins in the Siete Suyos mine, the Ánimas, Burton, Colorada, and Rosario veins in the Ánimas mine and the Nueva vein in the Chocaya mine. A three-stage paragenetic sequence is roughly determined for all of them, and includes (1) an early low-sulfidation stage that is dominated by cassiterite, pyrrhotite, arsenopyrite, and high-Fe sphalerite (FeS > 21 mol. %); (2) a second intermediate-sulfidation stage dominated by pyrite + marcasite ± intermediate product, sphalerite (FeS < 21 mol. %), stannite, and local famatinite; and, (3) a late intermediate-sulfidation stage dominated by galena and Ag-Pb-Sn sulfosalts. Electron-probe microanalyses reveal high indium enrichment in stage-2 sphalerite (up to 9.66 wt.% In) and stannite (up to 4.11 wt.% In), and a moderate enrichment in rare wurtzite (up to 1.61 wt.% In), stage-1 sphalerite (0.35 wt.% In), cassiterite (up to 0.25 wt.% In2O3), and ramdohrite (up to 0.24 wt.% In). Therefore, the main indium mineralization in the district can be associated to the second, intermediate-sulfidation stage, chiefly in those veins in which sphalerite and stannite are more abundant. Atomic concentrations of In and Cu in sphalerite yield a positive correlation at Cu/In = 1 that agrees with a (Cu+ + In3+) 2Zn2+ coupled substitution. The availability of Cu in the mineralizing fluids during the crystallization of sphalerite is, in consequence, essential for the incorporation of indium in its crystal lattice and would control the distribution of indium enrichment at different scales. The highest concentrations of indium in sphalerite, which is found in the Diez vein in the Siete Suyos mine, occur in crustiform bands of sphalerite with local “chalcopyrite disease” texture, which has not been observed in the other studied veins. In stannite, the atomic concentrations of In are negatively correlated with those of Cu and Sn at Cu + In = 2 and Sn + In = 1. Thus, atomic proportions and correlations suggest the contextualization of the main indium mineralization in the sphalerite–stannite–roquesite pseudoternary system.

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&lt;p&gt;Quantifying fluxes of particulate trace metals to the deep sea is a necessary step to understand their role in many oceanographic processes. The Gulf of Vera, in the SW Mediterranean Sea, is an ideal place to quantify these fluxes given the presence of a metal-rich mine tailings deposit in Portm&amp;#225;n Bay, in its northern shore. Portm&amp;#225;n Bay is one of the most extreme cases in Europe of mine waste impacts on coastal ecosystems, both inshore and offshore. About 57 million tons of tailings enriched in Fe, Pb, Mn, Zn, As, Ti and other metals were dumped there from 1957 to 1990 &lt;strong&gt;[1]&lt;/strong&gt;.&lt;/p&gt;&lt;p&gt;In the frame of the NUREIEV project, five mooring lines equipped with sediment traps and current meters were deployed in the wider Gulf of Vera. Three of the moorings were located in the middle course of three submarine canyons, one in the open continental slope and one in the deep basin. The monitoring period lasted for an annual cycle (March 2015 - March 2016). Our research focused on (1) measuring the temporal variability of particle fluxes in the study area, and (2) determining the concentration of particulate trace metals and metalloids (Zn, Pb, As, Ni, Cd, Cu, Co) as well as other metals (Fe, Mn, Ti) in settling particles.&lt;/p&gt;&lt;p&gt;Preliminary results within the following project NUREIEVA indicate that marine storms are the main processes triggering the transfer of particulate matter to the deep margin, mainly through hundred meters thick nepheloid layers moving not only along the submarine canyons but also across the open slope. High metal fluxes after storms reached up to 120.4 mg Pb m&lt;sup&gt;-2&lt;/sup&gt;d&lt;sup&gt;-1&lt;/sup&gt;, 282.3 mg Zn m&lt;sup&gt;-2&lt;/sup&gt;d&lt;sup&gt;-1&lt;/sup&gt; and 40.4 mg As m&lt;sup&gt;-2&lt;/sup&gt;d&lt;sup&gt;-1&lt;/sup&gt; in the canyon stations, four orders of magnitude higher than calculated in open Ligurian Sea &lt;strong&gt;[2]&lt;/strong&gt;. This suggests that submarine canyons are efficient pathways for the transfer of pollutants from the shelf to the deep margin and basin &lt;strong&gt;[3]&lt;/strong&gt;.&lt;/p&gt;&lt;p&gt;Peak metal concentrations found so far in the wider Gulf of Vera exceed those found in other canyons in the Mediterranean Sea &lt;strong&gt;[2, 4]&lt;/strong&gt;. The hypothesis that this could be related to the release of metals from the mine tailings deposit in Portm&amp;#225;n is plausible but would require further work to be confirmed, including determination of enrichment factors in each station, and discerning between Portm&amp;#225;n&amp;#8217;s and other potential metal sources.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;[1] Oyarzun, R. et al., 2013. Sci. Total Environ. 454-455, 245-249.&lt;/p&gt;&lt;p&gt;[2] Heimb&amp;#252;rger, L.E. et al., 2012. Chem. Geol. 291, 141-151.&lt;/p&gt;&lt;p&gt;[3] Canals, M. et al., 2013. Prog. Oceanogr. 118, 1-27.&lt;/p&gt;&lt;p&gt;[4] Palanques, A. et al., 2008. Mar. Geol. 248, 213-227.&lt;/p&gt;