Cross-folds

Abstract
Many recent investigators report the presence of “ cross-folds ” in mountain chains. The common right angle relations between such folds and the main trends suggest that they are genetically allied. Following the original suggestion of Argand, it is proposed that the superficial cross-folds are due to basement control (passive segmentation), whereas those in the deeper parts of geosynclines have been brought into being by the limitations of space (active segmentation).