metallic metals - Government of Manitoba

52(ibid); no sulphides were noted with the gold. Thesoutherly shear zone, widening locally to 6 m, wasfollowed for 600 m but showed relatively little veinquartz, except at the west end where free gold wasfound in the early days in a vein, 50 cm wide, with alength of 60 m.References: Cambell 1971; Davies et a/1962, p 51;Russell 1952a; Stephenson 1971, 1972; Stewartin prep; Stockwell & Lord 1939; Weber 1971a,1971b; Wright 1932The Oro Grande mine (C 30) was located nearthe north end of Beresford Lake, 10 km east of LongLake. The inclined shaft, 78 m deep, is about 400 mwest of the lake; it is connected, at the 40 m level, tothe Solo shaft, which is 160 m deep and located 150m to the southeast. All shaft-sinking was done, instages, between 1923 and 1933. The ore was inquartz-filled openings along the Oro Grande shearzone where it cuts a large diorite sill near theeastern contact with overlying volcanics of the RiceLake Group. The Oro Grande shaft is at the southend of a ridge of diorite which rises above thenearby swamps. lhe Solo shaft is also in the sill, butless than 50 m from its contact with tuffaceoussediments. The shear zone, which strikesnorthwesterly and dips to the east, contains veins,up to 6 m long, of sugary quartz. These veins,exposed in outcrops on the ridge, yielded free goldduring the early prospecting. The shear zone wassubsequently traced to the north by trenching, andthere is a 15 m prospect shaft 120 m north of theinclined shaft. Trenches and an open stope in thisvincinity showed white, cherty and glassy quartzlenses, bordered by sheared gabbro, which hasbeen altered to dark grey quartz-chloritecarbonateschists, with minor biotite schist. Theveins and the rusty-weathering wall-rocks containcoarse pyrite cubes, also pyrrhotite and minorchalcopyrite. Coarse gold was reported undergroundat many locations down to 70 m. Visiblegold and rare sphalerite were found in a recentsurvey of surface material (J.W. Stewart, pers.com.). lhe presence of specular hematite in thechloritic wall-rock appears to indicate hightemperaturemineralization. The mill operatedfrom 1932 to 1934, and 1938 to 1940, producing 164.9kg of gold and 16.3 kg of silver.The Gunnar mine (C 31), which was at the southend of Beresford Lake, less than 1 km west of theshore, produced 3101 kg of gold between 1936 and1942. Owing to the good vertical extent of the orezone,the main, 3-compartment shaft reached adepth of 625 m. A second shaft, 210 m to thenorthwest, was down to 114 m. The mineralizationis in andesite and basalt, including some pillow­pillow-lavas, near the south end of a dykelike body of albitegranite, about 45 m wide, that trends northerlyfor 2.5 km. Some smaller porphyry dykes,3 m or so in width, strike north-northwest throughthe volcanics. The main shaft is located immediatelynorth and east of the intersection of one such dykewith the principal mineralized shear zone, whichwas traced roughly east-west on the surface for 820m by numerous pits and trenches. The lavas withinthe shear zone have been altered to chloritic schistand soft, greenish grey carbonate schist. The pitsreveal a lenticular vein, less than 1 m thick,consisting of grey sugary quartz and ankerite, andwell mineralized in places with pyrite andchalcopyrite. Sixty metres west of the main shaft,the shear follows a contact between andesite andan easterly projection of the granite. The richestorebody was located near this contact. Althoughnearly 5 m wide in the volcanics, the shear is weaklydefined where it crosses the granite, wideningagain in andesites to the west. The wall-rocks, asseen in the pits, are heavily carbonated chloriteschists showing disseminated cubes of pyrite; theyalso contain quartz and andesine. Pyrite was themost abundant metallic mineral in all the ore-veins,but chalcopyrite, pyrrhotite, arsenopyrite,sphalerite and galena were also present. Visiblegold was common in the quartz; the highest valueswere found in grey sugary quartz where cut byveinlets of glassy quartz. Another indication ofhigh-grade ore was finely granulated, streaky pyritealong cracks insugary quartz; chalcopyrite,sphalerite and galena tended to accompany gold instreaks along these cracks. In the shear zoneadjoining the smaller shaft, some large but lowgrademasses of pyrite were found in packed grainsup to 1 cm across. The gangue minerals in all veinsincluded chlorite and carbonate with lesseramounts of albite, tourmaline, fuchsite and sericite.The rock-dumps have unfortunately been removedin recent years for road construction purposes.References: Campbell 1971 ; Cole 1938; Davies et al1962, p 51; Russell 1952a; Stephenson 1971,1972; Stewart in prep; Stockwell & Lord 1939;Traill 1970; Weber 1971a, 1971b; Wright 1932The Diana-Gem Lake mine (C 32), 18 km furthersouth, was less than 1 km from the Ontario border.The site is 3 km south of Gem Lake and 300 mnorthwest of Kickley Lake. The 3-compartmentshaft had reached 236 m in 1931. lhe earliestproduction was in 1928 but most of the mining wasdone between 1934 and 1936. Total production was235.5 kg of gold and 13.2 kg of silver. The mine wasclosed in 1938 but minor salvage operations tookplace in 1941. Regionally, the orebodies were on