The Northeast occurrence is located on the northeast flank of Mount Weir about 43 kilometres east of the community of Atlin.

The showing is located in the middle of the Surprise Lake batholith (Surprise Lake Plutonic Suite) which covers about 1100 square kilometres east and northeast of Atlin. The batholith is dated at 70.6 plus or minus 3.8 million years or Late Cretaceous (Map 52, notes). It is composed primarily of medium grained, equigranular alaskite which is essentially a leucocratic granite with microcline and orthoclase with subordinate quartz, and may or may not contain plagioclase and mafics. There are some coarse-grained quartz feldspar porphyritic varieties. The contacts between the various textural varieties are commonly gradational. Massive aplitic dikes crosscut the batholith and very coarse grained pegmatitic zones also occur within the alaskite containing large quartz and feldspar crystals and books of biotite. The width of these zones varies considerably, but the contacts are almost always sharp.

On the northeast flank of Mount Weir, mafic-rich dikes with sphalerite, galena, magnetite, hematite, quartz and danalite intrude alaskite (Fieldwork 1978, pages 106, 107).