This intrusive caused the folding, faulting, and metamorphism of the Jurassic sediments and the doming and propylitization
of the Eocene andesites.
At Opata, a partially exposed 5 km (3 mile) diameter mineralized system exhibits classic porphyry copper-style alteration including silicification, phyllic alteration and propylitization
in granodiorite with numerous breccia pipes and stockwork mineralization.
The dacite in the lower part of the stock is marked by strong propylitization
, sericitization and pyritization, whereas silicification dominates in the upper levels.