The 540 sq/km Rau property lies within the Tintina Gold Belt. It is situated in a highly prospective geological setting between the regional-scale Dawson and Robert Service Thrusts, which imbricate Paleozoic shales and silty carbonate rocks. Recent interpretation has identified striking resemblances between the geological setting of the Rau property and the northern part of the Carlin Trend. To view stratigraphic and structural similarities, please click on the following link:
The Carlin Trend is located in Nevada and is one of the world's largest gold districts. Gold deposits in this district are estimated to contain in excess of 5,000 tonnes (~160,750,000 oz) gold. Deposits within the northern part of the Carlin Trend account for over half of this total, with gold production and reserves in excess of 3,000 tonnes (~96,450,000 oz) gold. (Economic Geology; September 2003; v. 98; no. 6; p. 1063-1067).
Deposits comprising the northern part of the Carlin Trend are clustered in an approximately 160 sq/km area. The Rau gold discovery was made in 2008 when 18 diamond drill holes totalling 3423 m identified gold mineralization within the hinge area of a gently east-southeasterly plunging anticline. The host anticline has been traced 22 km west-northwesterly from a high level, Late Cretaceous granitic stock. Gold occurs in sulphide and oxide zones. The mineralized system is open from the discovery area in both directions along the anticlinal axis and at depth.
Gold mineralization is hosted in dolomitized or decalcified limestone near the crest of the anticline. The main sulphide minerals are pyrite, arsenopyrite and pyrrhotite, while accessory minerals include bismuthinite, scheelite and sphalerite. The thickest intersection from sulphide bearing mineralization averaged 1.71 g/t gold over 78.54 m from hole Rau-08-05.
Oxide gold mineralization is devoid of sulphide minerals. It occurs in intensely decomposed, porous limestone with occasional sections of massive boxwork limonite. Hole Rau-08-16, the furthest hole to the northwest, intersected 53.95 m of oxide mineralization that averaged 2.69 g/t gold. Oxidation at the Rau property may predate glaciation, which partially exposed the discovery area on the floor of a south facing cirque. Projections of the barely unroofed Discovery Horizon trend laterally beneath cover rocks on the adjacent valley walls, suggesting that there is good potential for extensions of the oxidized zone along strike to the northwest and southeast. This interpretation is supported by geochemical and geophysical data.
One of the major focuses of ATAC's 2009 exploration program will be further definition of the oxide gold potential using large diameter diamond drilling. The other main objectives are to expand the known zones and to discover new areas of mineralization elsewhere on the property.
The most significant assay intervals from 2008 are clustered in a 300 by 200 m zone at the west end of the drill area. All of the holes in this zone tested the Discovery Horizon which hosts both sulphide and oxide gold mineralization. Mineralized intervals average approximately 60 m thick within this horizon. Gold values are highest near the fold axis and gradually decrease down the fold limbs. No holes have been drilled along strike to the northwest of the zone and all of the holes to the southeast of it are not believed to have been drilled deep enough to intersect the Discovery Horizon. To view a map showing holes that intersected the Discovery Horizon, please click the following link:
Results from the 2008 exploration program are highly encouraging as they indicate a thick, laterally extensive system. Significant diamond drill intersections from the Discovery Horizon are tabulated below.
Hole # |
From (m) |
To (m) |
Interval |
Interval |
Gold |
Gold |
Rau-08-02 |
52.73 |
113.74 |
61.01 |
200.16 |
1.33 |
0.039 |
including |
52.73 |
60.72 |
7.99 |
26.21 |
3.00 |
0.087 |
and |
103.74 |
105.74 |
2.00 |
6.56 |
3.76 |
0.110 |
and |
111.74 |
113.74 |
2.00 |
6.56 |
5.30 |
0.155 |
Rau-08-03* |
9.14 |
62.55 |
53.41 |
175.23 |
1.73 |
0.051 |
including |
12.19 |
27.43 |
15.24 |
49.99 |
4.75 |
0.139 |
Rau-08-04 |
98.61 |
170.25 |
71.64 |
235.04 |
1.60 |
0.047 |
including |
111.61 |
117.61 |
6.00 |
19.68 |
3.97 |
0.116 |
and |
160.61 |
168.61 |
8.00 |
26.25 |
6.44 |
0.188 |
Rau-08-05 |
71.50 |
150.04 |
78.54 |
257.68 |
1.71 |
0.050 |
including |
71.5 |
77.38 |
5.88 |
19.29 |
6.73 |
0.196 |
and |
136.38 |
150.04 |
13.66 |
44.82 |
3.27 |
0.095 |
Rau-08-06* |
6.70 |
68.70 |
62.00 |
203.41 |
1.50 |
0.044 |
including |
21.70 |
27.70 |
6.00 |
19.68 |
3.68 |
0.107 |
and |
58.70 |
66.70 |
8.00 |
26.25 |
3.50 |
0.102 |
Rau-08-07 |
172.87 |
237.87 |
65.00 |
213.25 |
1.52 |
0.044 |
including |
172.87 |
186.87 |
14.00 |
45.93 |
5.20 |
0.152 |
and |
234.87 |
237.87 |
3.00 |
9.84 |
3.40 |
0.099 |
Rau-08-11 |
174.91 |
188.27 |
13.36 |
43.83 |
1.36 |
0.040 |
including |
232.65 |
235.65 |
3.00 |
9.84 |
1.62 |
0.047 |
Rau-08-16* |
19.81 |
73.76 |
53.95 |
177.00 |
2.69 |
0.078 |
including |
19.81 |
33.53 |
13.72 |
45.01 |
5.95 |
0.174 |
and |
53.34 |
65.84 |
12.50 |
41.01 |
3.22 |
0.097 |
Rau-08-18 |
134.02 |
137.02 |
3.00 |
9.84 |
1.96 |
0.057 |
* Holes Rau-08-03 and Rau-08-16 encountered mineralization directly beneath overburden cover and ended in mineralization. Recovery in both of these holes was poor; therefore the reported grades cannot be relied upon. Hole Rau-08-16 encountered four intervals between 25.69 and 70.10 m, ranging between 0.83 and 1.53 m in length, where virtually no recovery was possible. The nature of these intervals is unknown. Gold grade persists on either side of the intervals and in each case a value equal to the average of the gold grades from the two immediately adjacent intervals was assigned to the interval with no recovery. Hole Rau-08-06 also encountered mineralization directly beneath talus cover. None of these holes appears to have intersected the entire width of the mineralized zone.
The 30 km long Rau property was staked to cover potentially favourable areas for sediment-hosted gold mineralization based on the distribution of known showings, geophysical features and geochemical anomalies. Most of the property has received only first pass exploration. Helicopter-borne geophysical data has been compiled with reconnaissance-scale geochemical results to guide property-wide evaluation aimed at additional gold discoveries. Follow up work will first examine numerous targets within a highly prospective 6 km long corridor centred on the discovery area before assessing potential in the remainder of the favourable trend.
The 2009 drill program at the Rau property will utilize two drills initially. One drill will begin in early June and will be used as a scout drill to extend the known areas of mineralization. A second larger-diameter drill will start up in mid-June and will concentrate on definition drilling of the oxide zone, in the Discovery Horizon.
"The fact that the Rau property has many similarities to the northern Carlin Trend is a very significant development for ATAC and the Yukon." stated Graham Downs, chief executive officer of ATAC. "We look forward to utilizing Carlin deposit models to assess the Rau property and ATAC's other nearby properties."
The technical information on this page has been reviewed by Robert C. Carne, M.Sc., P.Geo., a qualified person for the purpose of National Instrument 43-101.
Rau Collar Locations Click to Enlarge |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |