Fig. 7. Lower fractured surface containing clear beach marks (a) the inset shows an overall image of the fractured surface, whereas the image on the right shows the clear beach mark zone as well the junction of C1/C2 which is encircled with a red dash line, (b, c, d) higher magnification images of the fractured surface showing beach marks which were observed to be consisting of finely divided lines and marked with dashed (red) line(e) a representative EDX spectrum in the red encircled region of (a)