I totally think this would make a great Indiana Jones plot. The mcguffin could be the Mica Hand (http://upload.wikimedia.org/wikipedia/commons/2/26/Hand_Hopewell_mica.jpg), and the villain could be slain by nature spirits for defiling the graves of the Hopewell or something.
I think that German writer did something in that capacty, only with the Western Indians.
However, about a year after the book had returned to the publisher's, the manuscript was consumed by the desert in a sand storm which lasted a whole year. Wiped clean by the wrath of God.