This guidebook is divided into two parts; a brief resume of the regional geology of the southern Gawler Craton; and descriptions for each of the excursion stops. The Gawler Craton is a large region of continental crust which was cratonized ca 1400 Ma and since then has been subject to only minor epeirogenic movement. It consists of a broad variety of Archaean to Early Proterozoic gneisses, granites, metasediments, and a range of Middle Proterozoic sediments, volcanics and granites. To the south it is bound by a series of faults defining the continental margin formerly connected to Antarctica (ca Commonwealth Bay in George V Land); to the east it is bound by the Delamerian Adelaide Fold Belt with the Torrens Hinge Zone delineating the actual boundary; and to the north and north west it is bound by the Musgrave Orogenic Domain. The latter boundaries are poorly defined although aeromagnetic and gravity data have variously been used to define them (e.g. Thomson, 1980). Basement of the Gawler Craton is best exposed in the southern regions from the Tarcoola Area through the Gawler Ranges to Eyre Peninsula. On this excursion we will be concentrating on the Eyre Peninsula exposures which can be regarded as typical and representive of most of the known Gawler Craton. There are some gaps in the stratigrapy to be examined on this excursion, viz. the Gawler Range Volcanics and the Roopena sequence(s), but these were the subject of an earlier excursion (Blissett and Thomson, 1978).