Analysis of lunar lineaments: Far side and polar mapping

Previous mapping of linear structures on the lunar near side shows that lin eaments are not equally oriented in all directions but rather have preferre d orientations. The preferred orientations of near-side lunar lineaments ar e roughly consistent with the tectonic pattern predicted by relaxation of a formerly larger tidal bulge on the Moon due to the Moon's continuing reces sion from the Earth. We have mapped lineaments on the lunar far side and bo th the polar regions as well as re-examined lineaments mapped in the sub-Ea rth and anti-Earth regions to determine if the lineament patterns observed in these regions are also consistent with being produced by the collapse of a once larger tidal bulge on the Moon. The lunar far side is found to have a lineament pattern similar to that previously observed on the near side, which is consistent with being produced by the collapse of a once larger ti dal bulge. However, the sub-Earth and anti-Earth regions show a lineament p attern indistinguishable from that observed on the rest of the lunar near a nd far sides, even though relaxation of a formerly larger tidal bulge would produce a significantly different pattern in these regions. Collapse of a once larger tidal bulge also predicts a near to far side lineament trend in the lunar polar regions, but mapped lineaments in the polar regions show n o evidence for such a trend. Overall, the observed lunar lineament patterns do not support the predictions of a global tectonic pattern due to the col lapse of a once larger tidal bulge on the Moon and therefore require an alt ernate explanation. (C) 2000 Academic Press.