Strandlines or elevated shorelines, located across the Murray Basin in south-eastern Australia, trace the preserved remnants of former emergent coastlines that developed during the Late Miocene (c. 7 to 4 Ma) marine regression. Strandline traces extend across an area of ~135,000 square km, and are still present for up to 300+ km inland of the present-day coast. The Late Miocene sands of the Loxton Sand formation are prospective for marine placer deposits of heavy minerals (HM), particularly zircon and rutile, with deposits mined across three states: Victoria, New South Wales and South Australia. The present study extends previous investigations of coastal evolution and the provenance of zircon in strandlines located in the south-western portion of the Murray Basin within South Australia (cf. RB 2015/00031). Preliminary geomorphological mapping done using satellite imagery and digital elevation models was used to characterise strandline patterns and assist in the selection of 8 field sites for sampling; 5 in the Loxton area and 3 along the western margin of the Murray Basin to the north and south of Naracoorte. Grain-size distribution was determined as part of the sedimentological analysis of samples from individual sites. Zircon grains were separated and characterised using optical microscopy and scanning electron microscopy with cathodoluminescence. The grains were dated using Pb/U isotope ratios from laser ablation inductively coupled mass spectroscopy analyses. In the Loxton area, thin sand beds with high mica content were also sampled and dated using Rb/Sr isotope ratios. Zircon age ranges were clustered to match possible source regions. The proportions of zircon age clusters were interpreted in terms of probable zircon source inputs and, by extension, the relative significance of likely river transport networks and coastal interactions. All samples recorded a comparatively high content of zircon grains with ages younger than 480 Ma, indicative of fluvial transport from bedrock terrains to the east and north. This is supported in the Loxton area by a predominance of mica grains aged c. 420 Ma, which coincides with the timing of igneous and metamorphic activity during the Lachlan Orogen and matches mica crystallisation ages recorded from basement rocks in western Victoria. The results are consistent with early development of a fluvial pattern of northern and eastern originating rivers, comparable to the present-day Darling and Murray river networks. These river networks were the dominant source of sediment and HM carried to the coastlines formed in the Loxton area and which prograded to the south-west. More southerly sediment dispersion in the region appears to have been largely influenced by longshore drift. The development of a fluvial network occupying the Douglas Depression, in western Victoria, is interpreted as a younger feature that developed towards final stages of the progradation of Loxton Sand and, as such, had little influence on sediment movement and Late Miocene coastal processes across the Murray Basin.