Mineralization of the driftwood property, McConnell creek district, British Columbia

The Driftwood Property is located in the southwest corner of the McConnell Creek map-area, about 87 miles north of Smithers, B. C. The property lies in a northwesterly trending belt of volcanic-sedimentary rocks that were mapped as Takla Group - Upper Division (Lord, 1948). The rocks are more correctly correlated with the Hazelton Group. They are bounded on the west and east by younger sedimentary formations. To the west is the Bowser Group and to the east, the Sustut Group. A Kastberg porphyry of Tertiary age has intruded the Takla Group rocks. Intrusion was into the epizonal environment and produced an irregular dyke-like body having a roof zone with anastamosing dykes and small roof pendants. The composition of the stock varies from granodiorite to quartz monzonite and alaskite. Differences in the stock are observed in textural, mineralogical, and chemical variations. Automorphism of the stock has resulted in propylitic alteration and contact metamorphism has resulted in an enveloping zone of hornfels. Temperatures at the intrusive contact as derived from heat flow calculations were probably a maximum of about 495 to 550°C and varied with respect to the type of rocks intruded.. A biotite hornfels of the albite-epidote hornfels facies has formed an aureole over 100 feet wide. A hornfels of the hornblende hornfels facies has been developed in narrow zones adjacent to parts of the intrusive contact. The porphyry is a metal-enriched intrusion in which some metallic grains formed in an accessory manner but most of the mineralization is epigenetic. The deposit has characteristics of both porphyry copper and quartz stockwork deposits with disseminated, fracture filling, vein, and replacement mineralization in the intrusive rock, hornfels, and skarn. The primary metallic minerals identified were: molybdenite, pyrite, pyrrhotite, chalcopyrite, arsenopyrite, sphalerite, galena, tetrahedrite, marcasite, aikinite, bournonite, and magnetite. Secondary or alteration minerals are rare and only minor goethite, maghemite, malachite, and ferrimolybdite were found. A five stage paragenesis is shown with at least three successive stages of veining. Sulphide deposition is believed to have started at temperatures in the order of 700°C and continued along with re-equilibriation of sulphides down to temperatures below 400°C and possibly 300°C for the sulphosalts.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat