The Discovery and Exploration of the Jacaré (``Alligator') Nickel Laterite-Saprolite Deposit, Pará State, Brazil

Abstract

The Jacaré Nickel Laterite deposit lies in the western part of the Carajas region, north-central Brazil. Originally identified in the 1970?s and then abandoned, the property was acquired by Anglo American Brazil in 2000 and has passed through several progressive stages of exploration. An initial investigation indicated that nickeliferous laterites were present over the northern part of the 18kms long, 2.5kms wide ridge at Jacaré, the result of deep tropical weathering of a bedrock mafic-ultramafic intrusive complex. Subsequent exploration has shown that the deposit contains three types of nickeliferous material comprising a siliceous laterite, a ferruginous laterite and a saprolite. Surface mapping, drill road mapping and sampling, pitting, drilling, and a reconnaissance TEM survey have all been employed to progress a geological evaluation and understanding of the deposit, outline the position and inter-relationships of the three main types of mineralization and identify additional resources. Nickeliferous saprolite in the northern and central parts of the deposit would be amenable to pyrometallurgical treatment, while the ferruginous laterites of the southern block could potentially feed a hydrometallurgical plant. The deposit at Jacaré is seen as an important component of the Anglo American nickel portfolio in Brazil, which includes the existing mine at Codemin and the Barro Alto project. Exploration continues at the Jacaré site, which is 100% controlled by Anglo American Brazil.