Qz-diorite porphyry (intramineral) exhibits secondary biotite over the ferromagnesian phenocrysts and groundmass (brown colour). Hydrothermal event goes on development of thin A-qz type veins array and later late-sericite alteration is overprinted. Finally, all event described above appear cut by E-massive pyrite veins.
I guess it is a hydrothermal breccia featuring vein type ore. It exhibits potassic alteration surrounded by phyllic alteration.
thanks for this post Footprint SpA, this sample shows a complex hydrothermal history characteristic of porphyry copper systems, with an initial high-temperature potassic alteration featuring K-feldspar and biotite, subsequently overprinted by a lower-temperature sericite-clay+-chlorite(?) alteration. This sequence is crosscut by quartz veins, which are typical conduits for mineralising fluids in such systems, and D-veins rich in pyrite, indicative of a later, cooler phase in the hydrothermal evolution. These features suggest a multistage mineralisation process with potential economic significance in porphyry copper-gold exploration.
Beautiful sample... may I please ask if the A veins carry mineralization...and E - veins .?
Exploration Geologist
7moEarly 2nd biotite-altered intrusive clast with veinlet stoped out by quartz eye porphyry intrusive(?) with pervasive illite(?) alteration subsequently truncated by A-veins then finally by sulfide-dominated veins?