With the announcement of the impending construction of a major new unsealed all-weather road through the Anangu Pitjantjatjara Yangkuntjatjara (APY) Lands of South Australia, running westwards for ~ 200 km from the Stuart Highway to Pukatja township (as per a 2014–15 SA State Government Budget announcement), significant amounts of new construction material will need to be located and quarried locally. It is already known that the doleritic to gabbroic dykes outcropping in the Musgrave Province can be an important source of construction materials for the region, since previously, some sites having high quality dense rock materials were proven and quarried for building the Stuart Highway and the Tarcoola to Alice Springs Railway. Three sites have clean, hard stone identified as suitable for: • rail ballast (Kulgera NT Quarry and Utah Bore Site), and • road surfacing aggregates, concrete aggregates and Class 1 crushed rock roadbase (DPTI Granite Downs Crushing Contracts 1 and 21, De Rose Hill Quarry Site). At these sites, under surface cover, the basic igneous dykes displayed a deeper weathering profile with some calcrete development; this material was found to be suitable for open surface road sheeting, as well as having also been used for constructing shoulders and the base course for the Stuart Highway, and for airstrip construction in the APY Lands. It is expected that any fresh rock material that may be extracted from below the weathered zone could be quarried and crushed to produce higher quality construction materials. However, in large areas of the APY Lands located well distant from the above quarry sites, where additional supplies of construction materials may need to be obtained in future, these target dolerite dykes typically range from subcropping to buried, and their exact distribution is uncertain. The Geological Survey of South Australia (GSSA) is aware that regional reduced to pole total magnetic intensity (RTP TMI) images can be used as a tool to remotely locate these units under cover. However, the exercise in the field of defining the extents of these dykes on the ground can be difficult where there is little or no outcrop. In the subject study, GSSA staff have used a hand held magnetometer to conduct four ground based traverses across known and inferred dolerite dykes in an attempt to determine the suitability of this field geophysical technique for delineating the extents of the dykes, since its wide application in the APY Lands would allow for easy and cheap resource mapping of likely construction material sites. The field trial demonstrated that using a hand-held Ultramag Geophysics GSM-19 magnetometer was a simple operation for one or two people, taking less than an hour to complete each of the described ~150 to 200 m long traverses. Magnetic field strength readings were taken at ~10 m station spacings along these traverse lines, which were orientated roughly perpendicular to the inferred strike of the buried dyke. Five readings were taken at each station point and averaged. The dykes traversed for the mapping trial are representative of the large dolerite bodies within the Musgrave Province, representing rocks that are both exposed and buried, are magnetically high strength or exhibit remnant magnetic lows, and which have high or low magnetic susceptibilities. The results of the four trial traverses done within the eastern Musgrave Ranges suggest that it is possible to delineate the approximate near-surface extents of dolerite bodies hidden under shallow cover using a modern hand-held magnetometer.