Aluminous mare basalts are the dominant lithology at the Luna 16 landing site in Mare Fecunditatis. For trace element analysis by micro-INAA techniques, we selected 23 of the 52 Luna 16 basaltic soil fragments studied by Kurat et al. (1976) and used a microcoring technique to extract microgram-sized samples from grain mount thin sections. Microprobe analyses suggest that most fragments are typical Luna 16 aluminous mare basalts, whereas one is a very-low-Ti (VLT) basalt. Fifteen fragments have bow-shaped REE patterns similar to those observed in much larger mg-sized Luna 16 fragments. Five other fragments are probably related to the main group Luna 16 basalts, but are either enriched in Ba, LREE, Ta, U and Th or up to a factor of 2-3 more enriched in all REE and incompatible trace elements. Trace element abundances show that three fragments are clearly different from the main group Luna 16 basalts: two samples show almost flat REE patterns and are about a factor of two lower in REE, whereas the third sample is similar in all trace elements to Apollo 17 VLTs. Apparently, this grain has been transported from Mare Serenitatis.