Lunar wrinkle ridges indicative of strike-slip faulting

In the mare regions of the moon, wrinkle ridges occur en echelon fashion within wrinkle ranges that are oriented in recurring directions that suggest fracture control. In general, the en echelon arrangement of wrinkle ridges is dextral in wrinkle ranges that trend between north and east, and sinistral in ranges that strike between south and east. Wrinkle ridges in mare material may be interpreted as (1) drag folds, or as (2) dikes occupying tension gashes. The drag folds or tension gashes have been formed by strike slip movements along faults within the underlying "highland" substratum. The consistent relationships between type of en echelon arrangement of wrinkle ridges and strike of associated wrinkle ranges further indicate that movements along the interpreted faults on the Moon have responded either to east-west regional compressions (if the ridges are drag folds) or to meridional compressions (if the ridges represent dikes in tension gashes).