Final Answer:
The portion along a fold where curvature is the greatest is termed the fold hin-ge line.
Step-by-step explanation:
The hi-nge line of a fold is the line along which the maximum bending occurs. It is the point where the two limbs of the fold meet and is typically characterized by the greatest curvature. The hin-ge line is an important feature of folds as it provides information about the folding mechanism and the amount of deformation that has occurred.
Here are some additional details about the hin-ge line:
The hin-ge line is not always a straight line. It can be curved or even irregular, depending on the complexity of the fold.
The hi-nge line is typically located in the middle of the fold limbs, but it can also be offset to one side or the other.
The hi-nge line is often marked by a change in rock type or a change in bedding orientation.
In summary, the hin-ge line is the portion along a fold where curvature is the greatest and is an important feature for understanding the folding process.