Four exploration licences distributed along the northern and north-eastern edges of Iluka's Group 4 of jointly reported tenements have been fully surrendered, after work performed there recently suggested that their perceived prospectivity for Tertiary sediment hosted heavy mineral sands (HM) accumulations had become substantially downgraded. Another twenty Group 4 licences still remain in force, out of the thirty-one that were originally granted. Since late in 2009, Iluka has subjected all major HM target zones of the Group 4 tenure to first pass regional exploratory traverse drilling, with follow-up drilling campaigns performed in what transpired as apparently prospective areas. Within the three of the four subject licence areas, a combined total of 118 vertical open aircore holes were completed for a total penetration of 4152 m, based on a regional reconnaissance drill traverse spacing of 4 km. Hole spacing was generally 2 km to 800 m apart along traverses. 161 selected drill cuttings composited over 1.5-metre depth intervals were submitted for laboratory heavy mineral analysis. Thin intervals of low grade, high trash content HM were recorded from EL 4349, within an iron indurated cover atop shallow basement. No prospective marine sands were encountered in the other three subject licence areas. Elsewhere, the most promising Group 4 region exploration results had come in 2010 with the discovery of the Thar prospect. In the central northern part of the Group 4 region, the Barton Range scarp veers southwards towards the Thar prospect. Thar lies exactly above a significant basement ridge of the Gawler Craton, which protruded through the thick Officer Basin sediments to form an HM trap in early Tertiary time. A drilling campaign undertaken by Iluka in late 2011 confirmed that the northern and eastern extensions of the prospect are limited, and following on from making that insight, Thar was interpreted to have been deposited within a lacustrine environment, and thus it no longer presented strong potential for containing significant HM mineralisation. The now surrendered tenements are located a minimum of ~20 km away from Thar, within distinctly different cover sedimentary environments which drilling has shown to be devoid of marine sands, or lacking in HM concentration. Drillhole traverses put in to the north of Thar revealed a terrestrial facies which can be correlated into three of the surrendered ground portions, while drilling done further out to the east failed to intersect any significant HM.