Strain Analysis of Kayo Formation around Teniya-zaki, Okinawa-jima

The Teniya area in Okinawa-jima situated just north to the Kayo area where Hayashi (1988,1999,1992) accomplished the strain analysis. The Kayo Formation around Teniya-zaki strikes generally northeast to southwest and dips to the west. The result of the strain analysis of the area is similar to that performed by Hayashi (1989); the bedding plane has the tendency parallel to the XY plane of the strain ellipsoid. The intensity of strain ε_s takes weaker value than that expected from the folding structure developed in the area. The reason is considered to be the competency contrast between quartz grains of strain marker and matrix. As the values of Ι_<sym> and χ^2 obtained from R_f / φ diagram are larger than the critical value of them, we conclude that there was no initial fabrics of quartz grains before deformation.