The role of seafood in the Norte Chico diet has aroused debate. Much early fieldwork was done in the region of Aspero on the coast, before the full scope and inter-connectedness of the several sites of the civilization were realized. In a 1973 paper, Michael E. Moseley contended that a maritime subsistence (seafood) economy had been the basis of the society and its remarkably early flourishing, a theory later elaborated as a "maritime foundation of Andean civilization" (MFAC). He also confirmed a previously observed lack of ceramics at Aspero, and deduced that "hummocks" on the site constituted the remains of artificial platform mounds.