Identification, distribution and significance of lunar volcanic domes

Abstract

Over 300 previously unrecognized volcanic domes were identified on Lunar Orbiter photographs using the following criteria: (1) the recognition of land forms on the Moon similar in morphology to terrestrial volcanic domes, (2) structural control, (3) geomorphic discordance, and (4) the recognition of land forms modified by dome-like swellings. Many terrestrial volcanic domes are similar in morphology to lunar domes. This analogy suggests that some lunar hills are in fact extrusive volcanic domes. Many of the domes identified in this paper seem to be related to basins and craters, and with the exception of local tectonic grid control few domes are related to any observable Moon-wide pattern. Domes are not uniquely found on maria. Dome formation probably spans a wide range of lunar time and activity in areas where domes are located may be continuing to the present as revealed by the close correlation of dome distribution with the distribution of lunar transient events. The overall morphology of a lunar dome is a poor indicator of the composition of the rock that forms the dome.