The nature of rays and sources of highland material in Mare Crisium

Although highland fragments are rare in the Luna 24 core, they should provide an important source of information on the sequence of formation and lithology of lunar east-limb basins. The numerous rays that cross the Crisium basin suggest several sources of highland materials. Both deposition of primary ejecta and reworking of local material were most likely responsible for the formation of ray systems in Mare Crisium. In addition to the fact that Luna 24 landed near the uprange end of a Giordano Bruno ray, incomplete sampling of the uppermost layer and formation of the ray by reworking of in situ regolith suggest that its materials may be scarce or not present in the core. Highland fragments present are most likely to be representative of several highland sources.