The behaviour of metals in deep fluids of NE Iceland.

In this contribution, we present some of the first data on the elemental signature of deep crustal fluids in a basalt-hosted, low-chloride magmatic-hydrothermal system. Down-hole fluid samples (850-1600 m) from wells in the Theistareykir and Krafla geothermal fields in the Northern Volcanic Zone of Iceland were combined with well-head samples of condensed vapor, cuttings of altered rock, and fresh basalt (being some of the first concentration data for volatile and semi-volatile elements (Sb, Tl, Bi, Cd and As) for this area of Iceland). Results show that the deep fluids are relatively enriched in base metals and (semi)-volatile metals (in particular Te, Hg, Re and Tl) compared to local basalt.

Seasonal variations of geofluids from mud volcano systems in the Southern Junggar Basin, NW China.

Variations in the chemical composition of geofluids and of gas fluxes are significant parameters for understanding mud volcanism and correctly estimate their emissions in carbon species, particularly greenhouse gas, methane. In this study, muddy water and gas samples were collected from the Anjihai, Dushanzi, Aiqigou, and Baiyanggou mud volcanoes in the southern Junggar Basin during the four seasons, around a year. This region hosts the most active mud volcanism throughout China.

Groundwater oxygen anomaly related to the 2016 Kumamoto earthquake in Southwest Japan.

Here, we report the groundwater oxygen isotope anomalies caused by the 2016 Kumamoto earthquake (M7.3) that occurred in Southwest Japan on April 16, 2016. One hundred and seventeen groundwater samples were collected from a deep well located 3 km to the southeast of the epicenter in Mifune Town, Kumamoto Prefecture; they were drinking water packed in PET bottles and distributed in the area between April 2015 and March 2018.

The growth of lithospheric diamonds.

Natural diamonds contain mineral and fluid inclusions that record diamond growth conditions. Replicating the growth of inclusion-bearing diamonds in a laboratory is therefore a novel diagnostic tool to constrain the conditions of diamond formation in Earth's lithosphere. By determining the carbon isotopic fractionation during diamond growth in fluids or melts, our laboratory experiments revealed that lithospheric monocrystalline and fibrous and coated diamonds grow similarly from redox reactions at isotopic equilibrium in water and carbonate-rich fluids or melts, and not from native carbon.

Groundwater oxygen isotope anomaly before the M6.6 Tottori earthquake in Southwest Japan.

Geochemical monitoring of groundwater in seismically-active regions has been carried out since 1970s. Precursors were well documented, but often criticized for anecdotal or fragmentary signals, and for lacking a clear physico-chemical explanation for these anomalies. Here we report - as potential seismic precursor - oxygen isotopic ratio anomalies of +0.

Origin of methane-rich natural gas at the West Pacific convergent plate boundary.

Methane emission from the geosphere is generally characterized by a radiocarbon-free signature and might preserve information on the deep carbon cycle on Earth. Here we report a clear relationship between the origin of methane-rich natural gases and the geodynamic setting of the West Pacific convergent plate boundary. Natural gases in the frontal arc basin (South Kanto gas fields, Northeast Japan) show a typical microbial signature with light carbon isotopes, high CH/CH and CH/He ratios.

Characterizing the Noble Gas Isotopic Composition of the Barnett Shale and Strawn Group and Constraining the Source of Stray Gas in the Trinity Aquifer, North-Central Texas.

This study presents the complete set of stable noble gases for Barnett Shale and Strawn Group production gas together with stray flowing gas in the Trinity Aquifer, Texas. It places new constraints on the source of this stray gas and further shows that Barnett and Strawn gas have distinct crustal and atmospheric noble gas signatures, allowing clear identification of these two sources. Like stray gas, Strawn gas is significantly more enriched in crustal He*, Ne*, and Ar* than Barnett gas.

Regional assessment of concentrations and sources of pharmaceutically active compounds, pesticides, nitrate, and E. coli in post-glacial aquifer environments (Canada).

There is growing concern worldwide about the exposure of groundwater resources to pharmaceutically active compounds (PhACs) and agricultural contaminants, such as pesticides, nitrate, and Escherichia coli. For regions with a low population density and an abundance of water, regional contamination assessments are not carried out systematically due to the typically low concentrations and high costs of analyses. The objectives of this study were to evaluate regional-scale contaminant distributions in untreated groundwater in a rural region of Quebec (Canada).

Exploring Rn as a tool for tracing groundwater inflows from eskers and moraines into slope peatlands of the Amos region of Quebec, Canada.

Peatlands can play an important role in the hydrological dynamics of a watershed. However, interactions between groundwater and peat water remain poorly understood. Here, we present results of an exploratory study destined to test radon (Rn) as a potential tracer of groundwater inflows from fluvioglacial landform aquifers to slope peatlands in the Amos region of Quebec, Canada.

Anthropogenic and natural methane emissions from a shale gas exploration area of Quebec, Canada.

The increasing number of studies on the determination of natural methane in groundwater of shale gas prospection areas offers a unique opportunity for refining the quantification of natural methane emissions. Here methane emissions, computed from four potential sources, are reported for an area of ca. 16,500km(2) of the St.

Ten-year helium anomaly prior to the 2014 Mt Ontake eruption.

Mt Ontake in central Japan suddenly erupted on 27(th) September 2014, killing 57 people with 6 still missing. It was a hydro-volcanic eruption and new magmatic material was not detected. There were no precursor signals such as seismicity and edifice inflation.

Methane baseline concentrations and sources in shallow aquifers from the shale gas-prone region of the St. Lawrence lowlands (Quebec, Canada).

Hydraulic fracturing is becoming an important technique worldwide to recover hydrocarbons from unconventional sources such as shale gas. In Quebec (Canada), the Utica Shale has been identified as having unconventional gas production potential. However, there has been a moratorium on shale gas exploration since 2010.

(222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.