Ann: Brolga and Aquila drilling update, page-30

eastwest IMO the relationship is contemporaneous.
DEG refer to felsic to mafic intermediary with signs of overprinting not only of the host intrusion but also the Mallina sediment fm.
A geological model on a (IMO) similar style deposit has several stages but to simplify has a the intrusion as it’s cooling and crystallising and also possibly interacting with country rock ( here it’s siliciclastic , so I’ll go on a limb and suggest silification),resulting in a change in oxidation state and sulfidation where sulphide is precipitated out of solution , then resultant pyrite and gold ( other reactions at footwall also occur).
There is also a result of this fluid forced into pathways under pressure from the crystallising intrusion mass ( tension veins) at right angles.
There are I feel clues going on here on site which in my mind suggest further connections back to origins about 3.1 Ga in the formation stages of the Mallina Basin.