In the 4-J area, the Lower Jurassic Unuk River Formation is unconformably overlain by Lower Middle and Middle Jurassic rocks from the Betty Creek and Salmon River Formations, respectively, all of the Hazelton Group.

The occurrence area is comprised of black argillite, conglomerate, greywacke, andesitic tuffs, and volcaniclastics. Bedding attitudes generally vary from north to northeast with steep to moderate western dips. The sediments and volcanics are intruded by two distinct phases of intrusive rocks. The older intrusive, a chloritic feldspar porphyry occurs as plugs and sills, and is generally in contact with the volcanic rocks. The younger intrusives, light green, 1 to 3 metre wide fine-grained hornblende-feldspar porphyry dykes, cut all the other rock types and exhibit a consistent northwest trend.

A zone of alteration from 10 to 50 metres in width extends hundreds of metres intermittently in a north-south direction. The zone consists of volcaniclastics and feldspar porphyry hydrothermally altered to carbonate-quartz-sericite-pyrite-limonite. This type of hydrothermal action is represented in the argillites as abundant hairline limonite-quartz-carbonate veins.

Two samples of sericite schist were taken in a zone of sericite-pyrite alteration: a tetrahedrite rich sample contained 7.30 grams per tonne gold and 39.5 grams per tonne silver; a pyrite rich sample contained 2.20 grams per tonne gold and 25.5 grams per tonne silver (Assessment Report 12387).

Work History

From 1980 to 1982, the Catspaw claim (southeast of 4J's) was staked by Elan Exploration Ltd and optioned to E & B Exploration. E & B undertook minor prospecting, sampling and geological mapping before returning the property to Elan. Several of the streams draining the Catspaw and Jim claims were noted to carry gold colours when panned by prospectors.

In 1983, the Catspaw claim was optioned to Teuton Resources Corp. Thee property was enlarged by staking the Four-J's claims and the Gamma claim. A stratiform lead-zinc-antimony (gold-silver) occurrence and a boulder train of argentiferous quartz sulfide mineralization was discovered on the John claim. This latter work was undertaken by Billikin Resources under option (the option was relinquished the following year) (Assessment Report 12387). The 4J Gold samples were collected in this year.

In 1989, Maple Resource Corporation Exploration entered into an agreement with Teuton to earn a 60 per cent interest in the Four-J's claim (Assessment Report 19612). A field program was carried out by Maple concentrating on the Main (4J (104B 128)), Centre, South (104B 124 area) and North Zones (new occurrence). The primary target areas were defined as: the sedimentary exhalative style lead-zinc-silver mineralization in the Main and North Zones and a zone of highly anomalous soil samples collected along contours northeast of the grid area. The Centre zone is located several hundred metres south of the Main 4J zone.

In 2006, a 427 line kilometre airborne electromagnetic and magnetic geophysical survey was successful in outlining a number of target areas worthy of further exploration. Principal among these was 4J, a complex EM anomaly situated under thin ice cover approximately 100-200m west of the eastern edge of the Smalles icefield. Other significant geophysical anomalies indicated were the EM conductors detected southeast of the 4J anomaly on the Catspaw claim and the discrete, oval-shaped Mag-EM anomaly detected near the southeast corner of the gossan covered by the Tennyson 1-4 claims. The showing covered by the survey include the 4-J (104B 128), 4-J Gold (104B 126), Portland (104B 082), Catspaw (104B 211), Catspaw South (104B 288) and Catspaw 146 (104B 343).

Refer to 4-J (104B 128) for further details of the 4-J and Catspaw work history of which the 4-J Gold is part of.