1911 Encyclopædia Britannica, Volume 10… (1911)
“ It much more frequently happens that the strata have been bent into arches and troughs, so that they can be seen dipping under the surface on one side of the axis of a fold, and rising up again on the other side. Where they dip away from the axis of movement the structure is termed an anticline or anticlinal fold; where they dip towards the axis, it is a syncline or synclinal fold. The diagram in fig. 2 may be taken to represent a series of strata (1-17) thrown into an anticline (AA′) and syncline (BB′) . A section drawn across these folds in the line CD would show the structure given in fig. ”
