Spatial evolution of an AMD stream in the Iberian Pyrite Belt: process characterization and control factors on the hydrochemistry

ABSTRACT

This paper presents hydrochemical data of an AMD stream, Poderosa Creek, in the Iberian Pyrite Belt, obtained between its source, in the Poderosa Mine portal, and its confluence with the Odiel River. The main objective is to establish potential interdependent relationships between sulphate and metal loads and the following physico-chemical variables: pH, electrical conductivity (EC), redox potential (EH) and dissolved oxygen (DO). All the parameters show an overall increasing tendency from the tunnel exit to the confluence at the Odiel River. The TDS and EC are two relevant exceptions. They behave similarly, showing a decreasing trend and a strong inflection that describes a minimum immediately after the discharging point. Spatial analysis combined with statistical tools reveal typical AMD processes and the respective physico-chemical implications. Inputs with distinctive hydrochemical signatures impose relevant modifications in the Poderosa Creek waters. This indicates low hydrochemical inertia and high vulnerability to external stimuli.

Editor D. Koutsoyiannis; Associate editor not assigned     

地下管网综合图的作业雷区探讨

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浅谈小型矿山测量方法及其应用

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P–T evolution in greenstone‐belt mafic amphibolites: an example from Plutonic Gold Mine,Marymia Inlier,Western Australia

The metamorphosed mafic rocks of Archean greenstone belts host major orogenic gold deposits, and may record information about changing pressure–temperature (P–T) conditions that could contribute to understanding of Archean geodynamic processes. Until recently, it was difficult to obtain good constraints on pressure and temperature from these rocks. Here we present results of P–T pseudosection calculations in the NCFMASHTOS (Na₂O–CaO–FeO–MgO–Al₂O₃–SiO₂–H₂O–TiO₂–O–SO₂) system, using as an example typical amphibolite facies metabasaltic rocks from the Plutonic Gold Mine in the Neoarchean Plutonic Well Greenstone Belt (PWGB), Marymia Inlier, Western Australia. The pseudosections together with observed mineral compositions and mineral assemblages in the rocks are used to argue that a previously unrecognized steep pressure increase (from ～3–4 kbar at ～500 °C to ≥8 kbar at ～600 °C) accompanied metamorphism to peak temperatures. The P–T data presented here could be the result of either horizontal or vertical tectonics. Existing models for the early evolution of the PWGB involve nappe stacking supported by relatively cold strong crust, with little overall change in thickness. While the available evidence from the study area and the wider region is not yet sufficient to confirm whether the peak metamorphic conditions were attained by horizontal or vertical tectonic means, the P–T data presented here can provide region‐specific constraints for computer modelling that may provide a more definite answer in the future.     

The effect of Ca–Fe–As coatings on microbial leaching of metals in arsenic bearing mine waste

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EH4法勘查祥云米甸煤矿隐伏塌陷区效果

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皖南黄山区坞石垄岩体地质地球化学特征及找矿意义

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A Test and Re-Estimation of Taylor’s Empirical Capacity–Reserve Relationship

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