利用氣體成份監測台灣北部潛在的岩漿活動(II)

It is a three-year monitoring project on
potential magma activity by geochemical
method in northern Taiwan. We have focused
on the gas sources of the Tatun Volcano Group in the first year. Helium, carbon and
nitrogen isotopic ratios results show that
large amount of mantle derived components
are involved in the gas samples in this area.
The highest helium isotopic ratio is obtained
from Da-Yiou-Keng. Up to 90% of
magmatic component was estimated for its
gas sources. It implies that there may be
magma reservoir underneath Tatun Volcano
area. However, no significant anomalous
variations of helium isotopic ratios of the gas
samples have been observed during last two
years. It suggests that the de-gassing
system in this area is relatively steady in the period.