A single traverse was surveyed across a marked aeromagnetic low in the Eastern Officer Basin. The traverse begins at Emu field from whence it extends approximately 76 miles in a northerly direction. Reflection shooting along this line revealed a probable sedimentary section in excess of 18,000feet with mappable structures. Gravity stations established at 1200feet, intervals along this line confirmed the presence of thick section and the configuration of the more pronounced structures. A series of refraction depth probes gave depths to a fairly high speed refractor which was much more shallow than the basement mapped by the reflection and gravity methods. It is considered that this refractor does not represent the base of the prospective section.