INTRODUCTION TO THE GUIDE Northern Yorke Peninsula (NYP) is within the southern portion of the Olympic Domain of the eastern Gawler Craton, which is arguably the world’s most fertile IOCG belt. That such a belt existed was only realised when Western Mining Corporation (WMC) stepped northward in 1975, after many years of exploration with North Broken Hill Ltd in the the Moonta-Wallaroo Cu-Au Mining Field area. WMC’s discovery was the Olympic Dam deposit, thus the NYP represents a major step on the path to the recognition of the IOCG-U system there and the subsequent definition of the Olympic Domain. A number of conditions need to be met in order that an IOCG prone environment can exist. These include a suitable brine-prone host succession, a major thermal event including significant magmatism, and deeply penetrating fractures as channel-ways and sites for ore deposition (e.g. Hunt et al. 2007; Skirrow et al. 2007; Groves et al. 2010). These conditions are met in the Olympic Domain, and therefore also in NYP. The intention of this field trip, brief as it is, is to provide an understanding of the Palaeoproterozoic and Mesoproterozoic geology of the part of the Olympic Domain that includes the historic Moonta-Wallaroo mining area and the coastal exposure of Rex Minerals' Hillside Cu-Au Project.