A statistical study of the directions of structural lineaments on parts of the Moon shows three significant preferred orientations that trend generally northwest, northeast, and north. Locally, many preferred directions are radial to large lunar impact basins, indicating that their formation influenced the direction of some fractures.

A systematic fracture pattern exists down to the smallest observable scale on both the near and far sides. The existence of such a pattern at the polar regions is less clear. Geometric regularity of preferred orientations of fractures of pre-Imbrian age indicates that a systematic set of fractures was formed over the lunar surface during the very earliest episode of lunar history, probably before the formation of many large lunar basins. The presence of these same fracture patterns on materials of younger age indicates that this initial fracture pattern was rejuvenated repeatedly through time.

First Page Preview

First page PDF preview
You do not currently have access to this article.