Rainbow

Intrusive-related Au

New Discovery

304 claims ~6150 ha

Selwyn Basin

Minfile: 105N 032

Coarse gold was reported along the Stewart River near the present day Rainbow property as early as 1906, when geologist Joseph Keele conducted the first official survey of the region.  Livingston Wernecke and Dr. Aaro Aho (a prominent Yukon geologist who helped to discover the Faro mine) have both written of spectacular high-grade gold samples brought through Mayo in the 1930s, reasoning that the gold likely originated along streams which flow through 18526’s Yukon Inc.’s current ground.  The source of this mineralization was not located (its discoverer apparently left with his find), and the area has seen little exploration since.  A regional survey conducted by a base metals company in the 1960s identified placer gold draining another part of 18526’s present property.  As the company was interested only in lead-zinc, it did not follow up on the find.  Later sluice sampling by 18526 Yukon Inc. along streams emptying into the Stewart River confirmed the presence of widespread visible placer gold, with coarse gold recovered from a stream draining the present property.

In 1999, Ron Berdahl discovered gold-bearing massive sulphides along Rainbow Creek, with a pyritic sample from a 1 m gauge zone running 4.1 g/t gold and 32.3 g/t silver.  Other samples ran up to 3.1 g/t gold, 4.8% arsenic, 0.28% bismuth, 0.23% copper & 0.24% lead.  In 2000, 18526 conducted a small, widely spaced contour soils program, revealing a gold anomaly spanning several claims and open off the edges of the survey.  Anomalously high Ag, As, Bi, Cu & Pb values were also present over a wide area.

The Rainbow property overlies the Robert Service Thrust, which locally puts Permian sedimentary units, similar to those found at Brewery Creek, over Triassic mudstones in a high-strain tectonic environment.  Several newly-discovered granitic dikes containing up to 1% sulphides are exposed on the hillside above the Rainbow Creek showings, and are thought to be surface expressions of a previously unknown and poorly exposed mid-Cretaceous intrusion.

The project area lies within the Tintina Gold Belt, the broad, arcuous metallogenic province that hosts such deposits as Pogo, Fort Knox and Donlin Creek.  Any intrusive underlying the claims would likely belong to the Tombstone Plutonic Suite.  High Bi levels in rock and soil samples are suggestive of a deep-seated IRGS, possibly analogous to Alaska’s Pogo deposit.  More work is needed to determine the nature and extent of the mineralization.