Under the agreement, South32 will provide US$1 million funding for generative work and acquisitions per year over two years.

Generative work will focus on copper and other base metal projects within the Laramide and Tertiary magmatic arcs of Arizona, New Mexico and Utah.

Any projects progressed to drilling can be selected as designated projects and will advance under separate options agreements.

South32 has selected five copper projects in Arizona to start advancing towards drilling: Midnight Juniper, Jasper Canyon, Sleeping Beauty, Dragons Tail and Lomitas Negras.

Midnight Juniper is only 1km from the Morenci copper mine, while Dragons Tail is 8km to the north of BHP and Rio Tinto's Resolution project.

If projects move to the designated stage, South32 can earn 100% by reimbursing EMX's holding costs, making option payments of $525,000 and spending $5 million on exploration over five years.

EMX will retain an uncapped 2% net smelter return royalty and receive annual advance royalty payments equivalent to 50,000 pounds of copper.

South32 will also have to make milestone payments when it defines a maiden resource, completes a prefeasibility study, and a feasibility study.

The alliance excludes South32's recently acquired Hermosa zinc project in Arizona.

South32 has a similar project generation agreement with AusQuest in Peru and Western Australia.