Department of Philosophy, History, Culture and Art Studies University of Helsinki PRE-COLUMBIAN EARTHWORK SITES IN THE FRONTIER REGION BETWEEN BRAZIL AND BOLIVIA, SOUTHWESTERN AMAZON Sanna Saunaluoma ACADEMIC DISSERTATION To be publicly discussed, by due permission of the Faculty of Arts at the University of Helsinki, in auditorium XII, on 26 October 2013, at 10 o'clock. Helsinki 2013