The principal aim of Flinders Diamonds Limited’s (FDL) exploration in the Chapel Hill area is to discover a commercial diamond deposit. The source of the "Echunga" diamonds, found in the alluvial gold workings within the Chapel Hill Fossicking Reserve (FR 393), is a primary target. Exploration Licences EL 2585 and EL 2739, in which FDL has an interest, surround the reserve. This report discusses the results of a joint FDL and PIRSA investigation undertaken to obtain new geoscientific data on the provenance of the Echunga diamonds. A participants' study of previous exploration records revealed that there is no report of confirmed kimberlite indicator minerals associated with those diamonds, nor is there any record of the stratigraphic position of the diamonds within the Tertiary sedimentary sequence, before they were removed. The assumption made therefore was that the diamonds recovered came from the gold-bearing basal conglomerate. Eleven trenches were excavated in and around the Chapel Hill Reserve during October-November 2002, to sample just above the Neoproterozoic/Tertiary unconformity for indicator minerals and diamonds, and to log the local stratigraphy. Neither diamonds nor 'normal' kimberlite indicator minerals were detected in detrital sediments filling palaeochannel streambed potholes eroded into the Aldgate Sandstone (a setting which probably hosted the past reported diamonds), although the trench bottom samples contained significant grain counts of gold and other heavy minerals. However, the basal conglomerate layer did contain some few grains of strongly weathered probable pyrope. A capped kimberlite, slightly uncovered by recent erosion, may be the source of the single fresh pyrope grain obtained by FDL from one good quality trap site sampled beneath Echunga Creek, at a site located 4 km south-west of the Chapel Hill Reserve. The chemistry of the pyrope suggests that it is from a diamond-bearing source, possibly the same one from which the Echunga diamonds were derived. Estimations of the direction towards source, that were made from measurements of imbrication structures preserved on pebbles in the Tertiary sediments, gave inconclusive results.