Modes of formation of lunar light plains and the detection of cryptomaria deposits

Abstract

The early volcanic and impact histories of the Moon are closely linked and the record preserved in surface morphology and samples is tightly convolved because of the interaction of the two processes. The deconvolution of the record is an important goal in order to assess early volcanic flux and the mode of emplacement of large crater and basin deposits. For example, lunar light plains have been variously interpreted as volcanic, impact, and volcanic covered by impact deposits. The development of criteria for the determination of the origin of light plains and the detection of cryptomaria is a key to the deconvolution of this early record. We outline the various hypotheses for the origin of and potential modes of occurrence of light plains and cryptomaria, and develop criteria for their recognition and documentation. We use the example of the Schiller-Schickard and Balmer cryptomaria to illustrate the application of these techniques to the problem of light plains interpretation and cryptomaria documentation