The carbon isotope content of dissolved inorganic carbon was measured for large cold springs in the central Oregon Cascades. Low 14C activities in some of the springs are interpreted to result from the dissolution of diffuse emissions of magmatic CO2, even though volcanic activity has not occurred in this area for more than 1300 yr. On the basis of dissolved magmatic carbon concentrations in th...

Introduction: Magmatic inclusions in Martian meteorites contain some hydrous minerals such as kaersutites [e.g., 1-2]. The characteristic of Martian kaersutites is their water-poor [3] and Ti-rich (~10 wt%) compositions. The presence of kaersutite gives evidence that Martian parent magma contained water. In fact, several attempts have been performed to estimate the water content in Martian magm...

N2/Ar and Ar/He relationships: Fluid inclusion magmatic gases are measured using quadrupole mass spectrometers and the data is compared to measurements of volcanic gas analyses. Data reported by Giggenbach from active volcanoes give N2/Ar ratios in the general range of 100 to 1000 whereas corresponding Ar/He ratios vary from 100 to 2. Plotted on a Ar/He vs. N2/Ar diagram the data defines a fiel...

Early Cambrian volcanic rocks of the Posht-e Badam tectonic block in Central Iran which is hydrothermally altered to green color rocks, hosts the Kiruna-type Iron Oxide-Apatite (IOA) mineralization in Anomaly 10 of Sechahun deposit. Geochemically, these volcanic rocks are classified as high-potassium calc-alkaline and mainly consist of rhyolite and trachyandesite. These rocks are important for ...

[1] We measure all stable noble gases (He, Ne, Ar, Kr, Xe) in spring waters in the Oregon Cascades volcanic arc and in eastern Oregon, USA. We show that in order to estimate magmatic helium (He) contributions it is critical to simultaneously consider He isotopic ratios, He concentrations, and mixing of He components. Our component mixing analysis requires consideration of all measured noble gas...