Preliminary Map No. 59: Geology of the Mount Attwood-Phoenix Area, Greenwood B.C.
View Map (PDF, 2.7 MB), (1:25 000)
Report (PDF, 2.4MB)
Preliminary Map 59 and the accompanying 35 page report give the results of a geological investigation in the vicinity of the town of Greenwood in south central British Columbia. The 22 geological units distinguished in this 250-square kilometre area include a wide variety of Paleozoic to Tertiary rocks that have been affected by multiple episodes of deformation and igneous intrusion.
The Paleozoic (?) Knob Hill Group is the oldest unit in the area. Metacherts and quartz chlorite schists predominate. The Permo-Carboniferous Attwood Group is mainly black argillite with lesser clastic, metavolcanic and limestone components. The Triassic Brooklyn Group is characterized by thick basal conglomerates with interfingers of shale and carbonate, and an upper unit of volcanic breccias. Chlorite to amphibole grade metamorphism affected all these rocks. Deformation produced faults and locally tight folds.
The Eocene Princeton Group consists of the sedimentary Kettle River Formation and the volcanic Marron Formation. The volcanics are phonolites, trachytes and andesites. Block faulting related to uplift affected these rocks.
Triassic to Tertiary intrusive rocks occur in the area. Compositions range from mafic to granite and syenite.
Strongly serpentinized ultramafic rocks interpreted to be intrusions form sill and dyke-like bodies.
Mineralization in the area consists principally of copper bearing skarn deposits and to a lesser extent, gold and silver bearing quartz veins with minor lead and zinc values. Stratabound volcanogenic (?) gold-sulphide mineralization has been discovered in the area. Metallogenic evaluations indicate that the extensive fault and fracture patterns, which characterize the area, served as channelways for mineralizing solutions mobilized by the igneous intrusions. The combination of a long geological history and a wide range in types of deposits insures good potential for new mineral discoveries in this old mining camp.
The Greenwood Mining Camp flourished from 1900 to 1976 and produced 32 million tonnes of ore that yielded 38 276 kilograms of gold, 183 102 kilograms of silver, 270 945 tonnes of copper, 966 tonnes of lead, and 329 tonnes of zinc.
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