Atocha Reports on Besshi
The Besshi Property consists of 800 hectares and is located 5 kilometres northeast of Aiken Lake on the Omineca Development Road 250 kilometres north of Fort St. James, B.C.
The Property covers a belt of volcanic and sedimentary rocks that was prospected by the Consolidated Mining and Smelting Company (CM&S, now Teck Corp) in the 1930's. Shallow till covers much of the property, however, significant showings of gold, copper, a pyrrhotite-rich massive sulphide and silver-lead-zinc were discovered on Polaris and Jupiter Creeks.
On Jupiter Creek more than 300 metres of drifting and 200 metres of crosscutting are completed on several gold and silver-base metal showings. The main structure, the Number 2 "vein", is a "shear-zone" structure composed of carbonate-altered pyritic graphytic rock with some green mica (mariposite) alteration. The showing has many aspects similar to “greenstone-type” or “orogenic-type” gold deposits. Based on historic assay plans, N. Carter, P.Eng. (1993) estimated the main drift exposed a mineralized zone of 1.3 metres wide assaying an average of 6.34 g/t Au and 42.5 g/t Ag, for a length of 24.4 metres. Cross structures host classical vein-type silver-rich galena and sphalerite mineralization in quartz-carbonate fissure veins.
In the Polaris Creek Area, a strongly (silicified and carbonatized) altered contact area between mafic volcanic and clastic sedimentary rocks have been traced by airborne and ground geophysical surveys for 3 kilometres. Showings of massive sulphide (pyrrhotite-pyrite) nine (9) metres in thickness are exposed in Polaris Creek Canyon. The massive sulphides are characteristic of a paleo-geothermal system and black smoker hydrothermal activity and could host a Besshi-type volcanogenic massive sulphide deposit. Although the massive sulphides exposed in Polaris Creek were barren of base and precious metals, such deposits can change facies along strike and in the stratigraphic footwall into productive base and precious metal environment. Soil geochemical surveys have outlined targets in the recessively-weathered gulley along strike east and west of the exposed massive sulphides. Copper-in-soil values range up to 275 ppm, zinc to 800 ppm silver to 3.8 ppm gold to 165 ppb and molybdenum to 120 ppm.
Also in the Polaris Creek area, approximately 550 metres above the massive sulphide horizon, an adit with several branches was driven a total of 45 metres to intersect quartz vein mineralization cutting porphyritic diorite found in talus. The adit reportedly stopped short of the target, however the talus material returned assays of between 6.9 and 415 g/t (0.2 and 12.1 oz/ton) gold. Geophysical conductors 10A and 10B, interpreted to be caused by a 5 to 10 metres concordant tabular body, are located along strike 100 metres southeast of the adit, as are anomalous copper-in-soil samples to 245 ppm Cu.
Perhaps of more significance, and approximately 850 metres above the massive sulphide zone, Consolidated Mining & Smelting Company found the "Discovery Zone", an area of quartz-carbonate veining in argillite measuring 35 by 6 metres, carrying pyrite, arsenopyrite, pyrrhotite, galena, sphalerite, chalcopyrite and minute particles of free gold. Grab samples from the veins yielded assays of up to 1015 g/t Au (60 oz/ton), with 36 samples of vein material averaging 2.2 oz/ton Au, with the entire zone estimated to carry 0.11 oz/ ton Au. Along strike from the “Discovery Zone” to the southeast, highly anomalous soil samples (to 616 ppm Cu, 2.0 ppm Ag and 165 ppb Au) with an associated zone of conductivity.
One hundred metres above the "Discovery Zone", Consolidated Mining & Smelting Company trenched a base metal occurrence called to "Nanny Zone", where a 20 to 100 centimetre thick zone containing chalcopyrite, pyrite and pyrrhotite yielded assays of 3.56% Cu, 2.1 g/t Au and 20.0 g/t Ag across 0.6 metres.
Atocha has not yet undertaken any independent investigation of the Besshi Property nor has it independently analyzed the results of previous exploration, and therefore the historical sampling should not be relied upon. However, the Company believes that these historical results provide a conceptual indication of the potential of the property and are relevant to ongoing exploration.
No drilling has been undertaken by Consolidated Mining & Smelting Company or any of the other operators to date despite the highly encouraging results. Hostrocks are Upper Triassic to Jurassic in age and are similar to the hostrocks in the Toodogonne epithermal district. The target at Besshi is a greenstone or epithermal Au-Ag deposit and/or precious metal rich VMS-style deposit.
The Besshi Property was one of the most important exploration targets for the Consolidated Mining and Smelting Company (COMINCO, now Teck Corp) in the late 1930’s. Prospecting outlined five significant gold showings, with 500 metres of underground development on the Jupiter Creek showings.
J. T. Shearer, MSc, PGeo, is the qualified person who supervised the preparation of the technical material of this release.
