Some basaltic and andesitic gases

Journal Article · Sat Feb 01 04:00:00 EST 1975 · Rev. Geophys. Space Phys., v. 13, no. 1, pp. 37-55

DOI:https://doi.org/10.1029/RG013i001p00037· OSTI ID:4135778

Anderson, A T

Data (mostly post-1963) on H$sub 2$O, B, CO$sub 2$, N$sub 2$, O$sub 2$, Ne, sulfur gases, Cl, $sup 36$Ar, $sup 40$Ar, Br, Kr, I, Xe, Hg, and Rn are reviewed. The compositions of volcanic gases are compatible with solubility and melt composition for H$sub 2$O, Cl, and possibly sulfur gases. For other gases there are either inadequate data or conflicting data (CO$sub 2$). Glassy basalts from the sea floor have substantial concentrations of both active and noble gases. It appears likely that magmatic gas of basalts at sea floor pressure is 60 percent SO$sub 2$, 20 percent H$sub 2$O, 10 percent H$sub 2$S, and 10 percent CO$sub 2$ at 1200$sup 0$C. The concentrations of Cl and H$sub 2$O in basaltic and andesitic gases trapped in large crystals in pumices from continental margins are about 10 times those of deep sea basalts. Detailed relationships suggest that at least some andesitic magmas develop in vapor-saturated environments. The restored or potential concentrations of H$sub 2$O and Cl in andesitic magmas are estimated and used as a basis for estimating the rate of igneous outgassing in island arcs and continental margins. The inferred rates of outgassing are such that the present quantities of gaseous elements in seawater and sediment would be exhaled in 10$sup 9$ to 10$sup 10$ years. The rates of outgassing of CO$sub 2$ from Kilauea volcano and of SO$sub 2$ from Pacaya exceed the rate which could be maintained by outgassing of erupted lava. These relations imply the existence of a larger source of these gases than that of the volcanic rocks. It seems probable that volcanic rocks are generally volumetrically small portions of subsurface reservoirs which may be vapor-saturated. Such a condition has major implications for crustal evolution, the origins of volcanic rocks, eruption mechanisms, and hydrothermal ore deposits. (auth)

• Research Organization: Univ. of Chicago
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-008205
• OSTI ID: 4135778
• Journal Information: Rev. Geophys. Space Phys., v. 13, no. 1, pp. 37-55, Journal Name: Rev. Geophys. Space Phys., v. 13, no. 1, pp. 37-55; ISSN RGPSB
• Country of Publication: United States
• Language: English

Related Subjects

*IGNEOUS ROCKS-- SORPTIVE PROPERTIES
640107* --Physics Research--Astrophysics & Cosmology-- Planetary Phenomena
BASALT
DATA
DEGASSING
FUMAROLIC FLUIDS
GASES
MAGMA
MELTING
N56700* --Physics (Astrophysics & Cosmology)--Planetary Phenomena
PRESSURE DEPENDENCE
SOLUBILITY
VAPORS
VOLCANIC ROCKS
VOLCANOES