I think the confusion may be in the term Hinge Axis vs Hinge Zone #4. The San Antonio ans SG#1 are in the hinge axis areas and are separate deposits from Hinge Zone #4.

A hinge zone is a fold along a parallel fault that has opened to allow fluids to deposit.

hinge fault ( ′hinj ′fölt ) ( geology ) A fault whose movement is an angular or rotational one on a side of an axis that is normal to the fault.