Other
Scientific paper
May 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995gecoa..59.1749t&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 59, Issue 9, pp.1749-1761
Other
36
Scientific paper
Volcanic vapors were collected during 1990-1993 from the summit crater of Kudryavy, a basaltic andesite volcano on Iturup island in the Kuril arc. The highest temperature (700-940°C) fumarolic discharges are water rich (94-98 mole% H 2 O) and have D values of -20 to -12%. The chemical and water isotope compositions of the vapors (temperature of thirteen samples, 940 to 130°C) show a simple trend of mixing between hot magmatic fluid and meteoric water; the magmatic parent vapor is similar in composition to altered seawater. The origin of this endmember is not known; it may be connate seawater, or possibly caused by the shallow incorporation of seawater into the magmatic-hydrothermal system. Samples of condensed vapor from 535 to 940°C fumaroles have major element trends indicating contamination by wall-rock particles. However, the enrichment factors (relative to the host rock) of many of the trace elements indicate another source; these elements likely derive from a degassing magma. The strongest temperature dependence is for Re, Mo, W, Cu, and Co; highly volatile elements such as Cl, I, F, Bi, Cd, B, and Br show little temperature dependence. The Re abundance in high-temperature condensates is 2-10 ppb, sufficient to form the pure Re sulfide recently discovered in sublimates of Kudryavy. Anomalously high I concentrations (1-12 ppm) may be caused by magma-marine sediment interaction, as Br/I ratios are similar to those in marine sediments. The high-temperature (> 700°C) fumaroles have a relatively constant composition (~2 mol% each C and S species, with ratio of about 3:1, and 0.5 mol% HCl); as temperature decreases, both S t and Cl are depleted, most likely due to formation of native S and HCl absorption by condensed liquid, in addition to the dilution by meteoric water. Thermochemical evaluation of the high-temperature gas compositions indicates they are close to equilibrium mixtures, apart from minor loss of H 2 O and oxidation of CO and H 2 during sampling. Calculation to an assumed equilibrium state indicates temperatures from 705 to 987°C. At high temperature ( 900°C), the redox states are close to the overlap of mineral (quartz-fayalite-magnetite and nickel-nickel oxide) and gas (H 2 O-H 2 -SO 2 -H 2 S) buffer curves, due to heterogeneous reaction between the melt and gas species. At lower temperatures (<800°C), the trend of the redox state is similar to the gas buffer curve, probably caused by homogenous reaction among gas species in a closed system during vapor ascent.
Hedenquist Jeffrey W.
Korzhinsky M. A.
Shmulovich Kirill I.
Taran Yu. A.
Tkachenko S. I.
No associations
LandOfFree
Geochemistry of magmatic gases from Kudryavy volcano, Iturup, Kuril Islands does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Geochemistry of magmatic gases from Kudryavy volcano, Iturup, Kuril Islands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Geochemistry of magmatic gases from Kudryavy volcano, Iturup, Kuril Islands will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1060339