Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/9861
AuthorsItaliano, F.* 
Yuce, G.* 
Uysal, I. T.* 
Gasparon, M.* 
Morelli, G.* 
TitleInsights into mantle-type volatiles contribution from dissolved gases in artesian waters of the Great Artesian Basin, Australia
Issue DateApr-2014
Series/Report no./378-379 (2014)
DOI10.1016/j.chemgeo.2014.04.013
URIhttp://hdl.handle.net/2122/9861
Keywordsdissolved gases
great artesian basin
mantle fluids
tectonic structures
Subject Classification05. General::05.02. Data dissemination::05.02.01. Geochemical data 
AbstractThe geochemical features of the volatiles dissolved in artesian thermal waters discharged over three basins (Millungera, Galilee and Cooper basin) of the Australian Great Artesian Basin (GAB) consistently indicate the presence of fluids from multiple gas sources located in the crust (e.g. sediments, oil reservoirs, granites) as well as minor but detectable contributions of mantle/magma-derived fluids. The gases extracted from 19 water samples and analyzed for their chemical and isotopic composition exhibit amounts of CO2 up to about 340 mlSTP/LH2O marked by a δ13CTDC (Total Dissolved Carbon) ranging from −16.9 to +0.18‰ vs PDB, while CH4 concentrations vary from 4.4 × 10−5 to 4.9 mlSTP/LH2O. Helium contents were between 9 and N2800 times higher than equilibrium with Air Saturated Water (ASW), with a maximum value of 0.12 mlSTP/LH2O. Helium isotopic composition was in the 0.02–0.21 Ra range (Ra = air-normalized 3He/4He ratio). The three investigated basins differ from each other in terms of both chemical composition and isotopic signatures of the dissolved gases whose origin is attributed to both mantle and crustal volatiles. Mantle He is present in the west-central and hottest part of the GAB despite no evidence of recent volcanism.Wefound that the partial pressure of helium, significantly higher in crustal fluids than in mantle-type volatiles, enhances the crustal He signature in the dissolved gases, thus masking the original mantle contribution. Neotectonic activity involving deep lithospheric structures and magma intrusions, highlighted by recent geophysical investigations, is considered to be the drivers of mantle/magmatic volatiles towards the surface. The results, although pertaining to artesian waters froma vast area of N542,000 km2, provide newconstraints on volatile injection, and showthat fluids' geochemistry can provide additional and independent information on the geo-tectonic settings of the Great Artesian Basin and its geothermal potential.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
australia_chemgeol_2014.pdf2.24 MBAdobe PDFView/Open
Show full item record

Page view(s)

166
Last Week
1
Last month
1
checked on Jul 24, 2017

Download(s)

58
checked on Jul 24, 2017

Google ScholarTM

Check

Altmetric