brief summary
Tyrrell property
| Lac Rocher property
| Boyer Lake property
Goldeye Explorations Limited
27 Blue Spruce Lane, Thornhill, ON, L3T 3W8, Canada
September 1, 2003
Discussion: On Thursday Aug 14th through Mon. Aug 18, 2003, the author had the pleasure of visiting the Tyrrell Twp. properties of Goldeye Explorations Limited.
The author has done research with the Geological Survey of Canada leading to a PhD, exploration with Newmont Mining and Gold Fields as Chief Geologist, and written papers on the regional metallogeny of the Kirkland Lake area not far away and visited the Tyrrell Twp. area previously.
Broadly speaking, Tyrrell Twp. falls in that portion of the Abitibi Supergroup which mantles a basement diapir known as the Round Lake Batholith, now a structural dome (fig.1). A number of volcanic cycles consisting of 1/ mafic (with or without ultramafic) volcanics and their co-eval intrusions, 2/ overlying intermediate to felsic volcanics with their co-eval intrusions and, sometimes 3./ derived clastic sediments (the Timiskaming). All these suites are typically accompanied by interlayers of exhalite activity which, though volumetrically insignificant are the dominant (though not the only) economic theme.
Structurally, ductile deformation can be related to progressive episodic emplacement of basement diapirs during the Archean and to the Kenoran orogeny at the end of Archean time. Mylonites participate in the release of strain accompanying the major orogenic events. In the vernacular, these are "shear zones". They typically occur at or near diapir margins, at mid-points (crush zones between batholiths, and at the relatively thin edges of the major volcano-stratigraphic components, (the large volcanic cycles). Remobilization of existing mineralization commonly occurs to varying degrees during these periods of complex deformation, and to a lesser degree during regional relaxation and dilation afterwards.
The remarkable similarity of Archean assemblages and their deformation histories on a world-wide basis allows for employment of the principle of symmetry, particularly in any one geographic sector where the opportunity of for major facies changes is relatively limited. One of the best known examples of the extremely economically productive use of this principle (though not Archean) was the discovery of the Viburnum trend in Missouri. The Viburnam trend is a mirror image of the Old Lead belt, on the other side of a basement dome. Its discovery ranks as one of the greatest exploration successes of all time.
The analogous technique in the case of Tyrrell Township is to examine what is on the other, better known northeast side, of the Round Lake Batholith dome, and then compare that with Tyrrell its mirror image to the southwest.
The better known, better exposed, far more explored, northeast flank is the domicile of the Matachewan - Larder-Cadillac "Break", consisting of an extremely complex stratigraphic package averaging 400 feet in thickness, dominated by auriferous carbonate and resident in Timiskaming sediments and volcanics capping the entire Archean assemblage. The volcanics within the Temiskaming are an unusual suite of highly alkaline (dominantly trachytic) flows and fragmentals, epiclastic sediments and epizonal syenitic intrusions co-eval with the alkaline volcanics. Kirkland Lake sits athwart a major litological break separating an enormous older volcano to the south and a basin filled with the Blake River Group, another major volcano, to the north.
The above three metallogenic elements elements host the major ore-deposits of the greater Kirkland Lake area: 1/ the (Kirkland Lake) Main Break, an unequivocal vein system in a complex fault, which has remobilized gold from its host epizonal syenitic sill complex, including numerous alkaline porphyries, augite syenite and aphanitic phases. Kirkland Lake is the largest single coherent gold-lode deposit in the world, at 24 million ounces produced and dwarfs most other similar deposits. In less fractured (i.e. less remobilized) alkaline epizonal intrusions, the "porphyry" (ie.disseminated) style of the gold mineralization is more evident, though small scale fracturing, at least, is omnipresent. The Young-Davidson mine at Matachewan is an example of this, and the Bidgood east of Kirkland Lake another.
The other major style of gold mineralization is as strata-bound lenses of probably exhalative gold mineralization in the carbonate zone. The single biggest example of this is the Kerr Addison Mine which has produced more than ten million ounces. The Kerr has several ore types; but, the main two, in the vernacular of the camp are the well known and visually distinctive "green carbonate ore", and the much more economically significant "flow ore". The latter graded a very respectable 0.5 o.t. Flow ore was highly sulfide rich, sufficient to qualify as massive sulfide by the definition; but the probably exhalative mineralization was evenly disseminated in a carbonate-rich siliceous, tuffaceous sinter.
Lastly, iron has been produced at the Adams Mine, south of Kirkland Lake, in a major zone of oxide exhalite. This iron formation locally has abundant sulfide and, every now and then, anomalous gold.
Holding up the mirror, Goldeye's properties in the Tyrrell area, on the diametrically opposite side of the Round Lake Batholith dome, have already been found to have many of the same attributes to varying degrees. These are:
1/ A thick, fully differentiated volcanic pile, itself possessing a past producer, Tyranite, and a prominent prospect, Juby. The pile is capped by derived clastic sediments which have been correlated with the Temiskaming by generations of government mappers.
2/ The presence of an alkaline suite of epizonal intrusions high in the gross stratigraphy, including apparent augite syenite (which was a significant ore host at Kirkland Lake) and aphanitic syenite, (locally called "trachyte").
3/ The Timiskaming suite is accompanied by a thick carbonate zone which persists along strike for at least several kilometers, as currently known by limited exploration and exposure, and is known to persistently carry highly anomalous gold up to an economically significant channel sample of 69 ft/0.17o.t.
4/ The carbonate zone and adjacent Timiskaming suite are fractured to various degrees, locally intensely, by a through going "Break" (or, in the vernacular, " shear zone), probably reflecting strain release at a major lithological break which happens to also be central between the enclosing batholiths.
5/ An oxide exhalite,":iron formatiom" in common usage, is present to the west. It has significant sulfide content and some anomalous gold values.
Conclusion
No doubt more extensive examination will find additional points of comparison; but, at this stage the similarities are rather remarkable. Clearly the gold potential of Goldeye's large property package is excellent and warrants significant exploration drilling.
