Page 235 - NEWGEN21-Proceedings-Full

Thursday’s Gossan – Our Early Exploration

System evolution

● Early extrusion of primitive sea-floor ultramafic (peridotite) ~ 630Ma basal

unit (thrust emplaced)

● Sedimentation of the Glenthompson sandstone and extrusion of the

hyaloclastite Fairview Andesite Breccia (plus tuffs and interbedded

sediments – minor shale)

● Thrusting and the sequence turned upright

● Intrusion of large composite diorite / granodiorite plutons

● Intrusion of the large, early ‘Victor’ porphyry – characterised as low-grade

Mo ± Cu with very deep (+300m) clay alteration – implication for gravity low

● Intrusion of a series of smaller porphyries on the northern margin of the

Victor porphyry

● Porphyry ‘D’ veins cut Phase 2 porphyries (eg. QDP) – either Phase 2

magma chamber or Porphyry 3 is the source of late-stage ‘D’ veins

● ‘D’ veins are re-fractured / brecciated and in-filled with high-tenor copper

sulphides – inferred prograde Porphyry 3/4 related copper mineralisation

56