Work History

Staked as Christina cl 1-7 (YB03811) in August, 1990, by S. Ebert and G. Couture, who performed geological mapping, silt and rock geochemistry and petrographic work in the same year.
Restaked as Rog cl 1-14 (YB65316) by Eagle Plains Resources Ltd and Miner River Resources Ltd in May/96. The companies carried out a reconnaissance mapping and rock sampling program later in the year.

Capsule Geology

The area is located in the north-central portion of the Selwyn Basin, near the boundary with the Mackenzie Platform. The area is underlain by Paleozoic sedimentary rocks which have been intruded by mid-Cretaceous granitic intrusions.
The occurrence is situated 14 km west of Emerald Lake and covers a porphyry copper-gold target. A 900 x 400 m area containing disseminated sulphides and arsenopyrite-tourmaline-quartz veins occurs along the south flank of a mid-Cretaceous granite stock assigned to the Tombstone suite, which intrudes Devonian to Mississippian slate, argillite and chert assigned to the Earn Assemblage. Petrographic studies show that the host intrusion is hydrothermally altered. A stockwork zone of secondary orthoclase and biotite forms a potassic alteration halo around the south margin of the intrusion, and is overprinted by sericite replacing plagioclase and chlorite replacing biotite. The alteration zones appear to be centred on a magnetic high.
Mineralized veins ranging in size from about 2 mm to 37.5 cm wide (average about 3 cm), occur along joints
and form up to 10% of the rock. The veins are zoned, with quartz on the outside and tourmaline and arsenopyrite in the centre. Chalcopyrite, pyrite, malachite and azurite also occur in the veins and as disseminations in the intrusion. Most of the veins return anomalous copper values ranging from 231 ppm Cu to 5.31% Cu, while gold values range from 0.02 to 14 g/t Au. Silver values range from 1.3 g/t to 79.5 g/t Ag and arsenic values are almost all anomalous. A few specimens also returned anomalous values for Bi, Ba and Mo. A specimen of unveined granite assayed 202 ppm Cu, 0.52 g/t Au and 3.7 g/t Ag.
Five hundred metres south of the intrusive contact, brecciated siltstone with a matrix of tourmaline and arsenopyrite is cut by mineralized quartz veins containing up to 25% arsenopyrite and variable amounts of pyrrhotite, pyrite and chalcopyrite. Assays of the breccia averaged 2 g/t Au, with up to 1% Cu and 31 g/t Ag. Late stage aplite dykes cut both the mid-Cretaceous intrusion and the sedimentary rocks. All of the streams draining the east side of the intrusion returned anomalous copper values, with a few also returning anomalous Au, Ag, Pb, Zn and Mo values.
Eagle Plains and Miner River Resources¿ exploration program was designed to verify results obtained by Ebert in 1990. A 1.5 m chip sample collected across the breccia zone returned of 4.6 g/t Au and 111 ppm Bi. A 1.5 m chip sample collected from a 25 cm wide quartz-arsenopyrite vein containing 10% arsenopyrite returned 1.8 g/t Au and 827 ppm Cu.

References

S. EBERT, Feb/91. Assessment Report #092956 by S. Ebert.

EAGLE PLAINS RESOURCES LTD AND MINER RIVER RESOURCES LTD, May/97. Assessment Report #093614 by J.R. Dickie.

GORDEY, S.P., AND MAKEPEACE, A.J., 1999. Yukon digital geology, S.P. Gordey and A.J. Makepeace (comp.); Geological Survey of Canada, Open File D3826, and Exploration and Geological Services Division, Yukon, Indian and Northern Affairs Canada, Open File 1999-1 (D)