There is a nice little figure showing total magnetic intensity...

There is a nice little figure showing total magnetic intensity for highland plains, wonarah and surroundings in the mantle minings(i don't hold) quarterly report. Worth a quick read of the phosphate section, suspect Mantle haven't got much hope of finding a decent phosphate deposit.

Buchanan Dam/Alroy look to be a very promising. Are the historical intercepts from water bores, or was there targeted drilling ?

Surprised poz hasn't drilled a few holes at Buchanan Dam and Alroy ? Pretty good chance of finding some phosphate there without uranium/iron contamination etc.