カメルーン西北部の温泉ガスの希ガス同位体と化学組成

概要

論文の詳細を見る
We have measured noble gas elemental abundances and isolopic compositions, and chemical compositions in seven gas seeps and one lake water from northwestern Cameroon, West Africa. Major chemical composition is CO_2 except for Gesel spring and Lake Monoun. There is no correlation between chemical compositions and noble gas isotopes. Enrichment of Kr and Xe and depletion of Ne relative to Ar are found in the most samples, suggesting that these gases originated from the atmosphere through dissolution in water at low temperature. Neon isotopic compositions can be explained by mass-fractionated air or by mixing or mixing between air and Loihi-Kilauea component, while they are distinguished from MORB type neon. Argon istotopic compositions indicate that there is slight ^<40>Ar excess in some samples. Observed ^4He/^<40>Ar ratios do not agree with the value estimated from radioactive decay of K, U, and Th in Cameroon volcanic rocks.
特定非営利活動法人日本火山学会の論文
1992-06-01