[1] Duarte excavated hundreds of shell middens throughout Brazil which had been mined for lime since the beginning of the colonial period.

[2] He also conducted excavations along the coast of São Paulo state, which discovered a much-publicized pre-historic human skull known as "Miss Sambaqui".

In addition to his archaeological work, Duarte was a leading proponent of Brazilian culture, folklore and art.

[1][2] Duarte returned to Brazil after World War II, and brought with him a number of European archaeologists he had met while in exile.

Archaeological preservation laws were poorly enforced by the dictatorship in the 1960s and 1970, and Duarte fought in this period against the destruction of shell middens.