1997 Volume 62 Issue 1 Pages 25-34
Zircon Fission-Track Analysis (ZFTA) as a geological clock is based on zeta age calibration and track length measurements. Fission-track dating samples are classified into four types according to combination of two factors of 1) homogeneity in fission track age and 2) heating effect to fission track age. The four types of samples are (a) homogeneous and unheated, (b) heterogeneous and unheated, (c) homogeneous and heated and (d) heterogeneous and heated. As an example of ZFTA applied to the four-type samples, the author reviewed recent fission track dating studies in Japan as follows: (a) volcanic ash layers of the Kazusa Group in the Boso Peninsula, (b) the Pliocene Hirosegawa Tuff Member of the Sendai Group in Northeast Honshu, (c) the MITI “Honjo-oki” well and (d) the MITI “Mishima” well, respectively. Studies on the two exploratory test wells show ZFTA is a useful tool for petroleum exploration in Japan.
