Publication Date:
2024-05-16
Description:
The Caviahue-Copahue Volcanic Complex is one of the most studied active volcanic systems in the South
American Andean range, and yet little research has focused on trace and rare-earth elements of waters, especially
during an eruptive cycle. In this study, we sampled and investigated natural waters from 23 sites (involving the
crater lake, hot springs, streams, rivers, and bubbling pools) in two campaigns in 2017 and 2018, using physi cochemical parameters, major, trace and rare-earth elements concentrations. With this novel dataset, it was
possible to identify, characterize and compare three groups of waters with distinctive hydrofacies. Indeed, the
normalization of water compositions against host rock concentrations showed a particular trace element pattern
for each group of waters. Although the absolute concentrations of the elements in each sampling site changed
from 2017 to 2018, the normalized patterns did not. Boron, As, Cd, Tl, Se, and Te, commonly recognized as
volatile, are the main trace elements that magmatic gases supply to the system headwaters, whereas elements
such as Ca, K, and Ba are affected by precipitation of secondary minerals (gypsum, anhydrite, barite, jarosite, and
alunite). Furthermore, the main river draining the summit volcano shows a steep decrease in As, Cr, and V
concentrations correlated to the precipitation of Fe and Al hydroxysulfates (schwertmannite and basaluminite,
respectively). Moreover, it is the first time that a comparison between the different water groups is made using
the patterns of the rare-earth elements, allowing us to identify and separate depletion patterns due to dilution
processes from those due to precipitation processes.
Description:
Published
Description:
121602
Description:
JCR Journal
Keywords:
Copahue volcano
;
Hydrological system
;
Geothermal
;
Trace elements
;
Rare earth elements
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
