Linear ptygmatic folded quartz veins. Weekeroo, South Australia.
PhotoID331
Linear ptygmatic folded quartz veins. Weekeroo, South Australia.
PhotoID331
Photograph: Jim Talbot
Reference: Other photos of folds with enveloping surfaces may be seen at: http://myweb.facstaff.wwu.edu/talbot/cdgeol/Structure/Fold/Folds1/Fold_styles.html#ptygmatic