Regional hydrogeochemical mapping in Central Chile: natural and anthropogenic sources of elements and compounds
Carmina O. Jorquera
Christopher J. Oates
Jane A. Plant
Kurt Kyser
Christian Ihlenfeld
Nikolaos Voulvoulis
10.6084/m9.figshare.3453872.v1
https://geolsoc.figshare.com/articles/journal_contribution/Regional_hydrogeochemical_mapping_in_Central_Chile_natural_and_anthropogenic_sources_of_elements_and_compounds/3453872
<p>Geochemistry is a key tool in identifying sources of elements for both mineral exploration and environmental purposes. This
study evaluates the first systematic regional hydrogeochemical survey for environmental assessments of the classic Andean
copper mineral province and the Andina–Los Bronces mining district of Central Chile. One hundred and forty-five water samples
were collected systematically in the Valparaíso and Metropolitana Regions of Central Chile, including the capital, Santiago.
The concentrations of more than 70 elements and compounds were determined using inductively coupled plasma mass spectrometry
(ICP-MS) and ion chromatography (IC) along with the stable isotopes (δD, δ<sup>18</sup>O, δ<sup>34</sup>S, δ<sup>18</sup>O<sub>SO4</sub>, δ<sup>15</sup>N and δ<sup>18</sup>O<sub>NO3</sub>) and used to define the geochemical baselines in the area and distinguish between different sources. The geochemistry demonstrates
the potential to distinguish between natural (bedrock, hydrothermal alteration and mineralization) and anthropogenic (agriculture,
sewage and urban) sources of elements. The distribution patterns of many chemicals show a strong correlation with the presence
of evaporitic components (Ca, SO<sub>4</sub><sup>2-</sup>, Sr, K, Rb, total dissolved solids (TDS)), hydrothermal alteration and sulphide mineralization (Cu, Zn, Ni, Cd, Co and REEs).
High concentrations of nitrate, phosphate and alkalinity occur downstream of agricultural areas and reflect pollution from
fertilizers. Overall, the catchment areas affected by mining activities are relatively small and highly localized compared
to those affected by agriculture and urban centres.
</p>
2016-06-21 11:44:11
mineralization
source
compound
alteration
hydrothermal
agriculture
δ 34 S
plasma mass spectrometry
REE
mining
Andean copper mineral province
TDS
δ 18 O
concentration
Regional hydrogeochemical mapping
IC
Central Chile
anthropogenic
Geology