Sandfire only farmed into Auris' Morck's Well project at the end of March and can earn 70% on delineation of a 50,000 tonne copper resource.
The mid-tier copper producer started aircore drilling last Wednesday.
One hole hit visible supergene copper mineralisation, and another two hit weakly oxidised sulphide copper mineralisation.
Intersections within two of the holes had sulphide content sufficiently high to be classified as massive sulphide.
Auris CEO Wade Evans told ResourceStocks Sydney yesterday that he got the call on Friday afternoon.
Sandfire and Auris both called trading halts before Monday's open.
"The last time Sandfire was in a trading halt it was when they discovered Monty," Evans said.
"Hopefully we'll have similar...