FOLD, INTERLIMB ANGLE OF
Fleuty M J, Description of folds. Proc. Geol. Assoc Engl. 1964
IL angle:180° to 120° OPEN
IL angle:120° to 090° GENTLE
IL angle:090° to 060° CLOSE
IL angle:060° to 030° TIGHT
IL angle:0° ISOCLINAL
IL angle:NEGATIVE ELASTICAS