Geologic Interpretation of the Study of Lunar Rocks

Abstract

The hypothesis on an internal origin of lunar rocks of gabbroic type is supported by experimental petrologic data obtained by the author. The temperature interval of their crystallization from a dry silicate melt is given.Lunar gabbroic rocks of the Tranquillity Base are compared with paleobasalts of north-eastern Bohemia, eucrites and associated rocks of the British Isles and meteoritic eucrites of poikilophitic texture.The metasomatic origin of lunar anorthosites displaying a mosaic texture in deeper parts of the volcanic apparatus is postulated.An analogy is thought to exist between the Tertiary volcanic areas of Mull, Ardnamurchan and Rum in Scotland and the Ptolemaeus, Alphonsus and Arzachel regions of the Moon in the overall tectonic structure and the development of tectono-volcanic cirques. By analogy the possibility of the presence of more basic rocks in the rim and on the floor of the Moon subsidence calderas and of more acidic rocks of anorthositic to trachyandesitic chemistry in the central peak is presumed.The mode of origin of double-craters of Cyrillus-Theophilus type is suggested to be similar to the origin of two consecutive volcanic rings of Mull.The ring- and radial complexes of wrinkle ridges of Lamont type are compared with cone sheets and radial dykes of the central type tectono-volcanic complex of Mull.