At the time of writing (March 1967) there are six electrically logged oil exploration wells in the Gambier Embayment. These wells are still relatively widely spaced so detailed correlation is not feasible at this stage. However, broad similarities between the electric logs of Mt. Salt No.1 and Caroline No.1 suggest reasonably positive correlation of several subdivisions of the Lower Tertiary and Upper Cretaceous sequences. However, the subdivisions established near the deepest part of the basin are sometimes difficult to recognise in wells toward the northern margin of the basin. Generally, characteristics of the electric and gammaray logs alone are used for correlation, but the lithology of the cuttings is also taken into account; especially where the electric log coverage is incomplete or insufficiently characteristic. For practical reasons, the logs are initially sub-divided into Lower Cretaceous (Otway Group), Upper Cretaceous (Sherbrook Group), and Lower Tertiary sequences. Each subdivision is shown on a separate plate. The Lower Cretaceous sequence is discussed in another report on conjunction with petrological and heavy mineral determinations. (Rochow 1968).