Mare volcanism and lunar crustal structure

It is pointed out that the concept of hydrostatic head, the height to which a fluid at a given pressure will rise in a gravitational field, can be usefully applied to magmatic liquids and to a number of problems in volcanology. For the moon, hydrostatic head arguments are an essential ingredient to explanations of mascons and of the scarcity of farside maria. In the reported investigation, simple hydrostatic concepts are extended to synthesize results from experimental petrology, lunar chronology, thermal history models, seismology, and gravity. Attention is given to a scenario for early lunar history, the density of lunar rocks and basaltic liquids, the thickness of the lunar crust, the source depth of mare basalt versus time, hydrostatic considerations with respect to the occurrence of high-titanium and low-titanium mare basalts, the structure of mascons, and the extension of the concepts of hydrostatics to the parent liquids of other basaltic rocks returned from the lunar surface.