box fold

box fold

[′bäks ‚fōld]
(geology)
A fold in which the broad, flat top of an anticline or the broad, flat bottom of a syncline is bordered by steeply dipping limbs.
References in periodicals archive ?
But as evident from the pole and contour diagrams of the Western part (figures 3d and 4d) the fold could be of broad or rounded hinge similar to a concentric fan or box fold.
The box folds up by overlapping the three side pieces.
You also can't cook on a rainy day, but the box folds up to double as a thermal bag so it can keep food warm for quite a while.