1944  Miller in King et al., p.32, probably identical with
               Loc.20, = LOC6502, and with LOC3997.
     1972  Davis: 118. Concretionary shales (beds 5 and 7 of Difunta section) along strike between Cerro Wencelao
              on the south  to 300 m W of El Indio on the North, Valle de las Delicias.