Seabridge Gold


Overview of 2017 Exploration Program

Seabridge is pursuing a classical model of metal deposition at Iskut which seems to explain the known data. In our view, Iskut hosts district-scale porphyry-style mineral systems similar to our nearby KSM project. These systems account for Iskut's numerous gold and copper mineral occurrences. Our data suggests these systems could be largely intact from top to bottom, unlike KSM. Work is concentrating on the upper parts of these systems, targeting the high-grade gold potential which historically has been the hallmark of the Iskut district. The primary focus is on a lithocap feature at Quartz Rise. Lithocaps typically host the epithermal top of a porphyry system and anumber of high grade deposits have been found in this setting.

Seabridge's first exploration program on the Quartz Rise lithocap target consisted of 10 core holes totalling 4,459 meters. This drilling found evidence of a gold-bearing intermediate sulfidation epithermal system beneath the Quartz Rise lithocap as anticipated. Intercepts included 1.5 meters grading 8.26 g/T gold in QR-17-01 and 1.5 meters grading 74.1 g/T gold in QR-17-07. Sampling of a cliff face north of Quartz Rise returned very high grades ranging from 1.49 to 125.3 g/T gold. An economic source for these gold concentrations was not found in the 2017 drilling but the data acquired has defined a target (see below) which could account for these high grade results. A second exploration program is being planned for 2018 to pursue this target.

The 2017 drilling tested a graben feature discovered during surface work on the lithocap. This graben appears to have constrained the most intense hydrothermal alteration in the area of the lithocap. Drilling focused on the southeastern portion of the graben. Geophysical work completed at the end of the 2017 program suggested that the northwest portion of the graben should be targeted in 2018. The next program will include additional geophysical surveys and drilling along strike of this graben to the northwest. Drill tests will be orientated to optimize intersections with northeast structures and stratigraphic intervals which the 2017 program has determined to be the most favorable for higher gold concentrations.

The system at Quartz Rise has all the earmarks indicating the potential for a significant discovery. Iskut''s similarities with KSM are persuasive and this knowledge should help us zero on the potential at Quartz Rise.

2017 Program Description

The program at Quartz Rise began with geological mapping which featured a shallow northeast dipping sequence of Jurassic felsic volcanic rocks deposited unconformably on Triassic marine sedimentary rocks. This is the geological time break that has proved to be productive elsewhere in the region. The entire section of volcanic rocks shows leaching and textural destruction consistent with acidic alteration within an extensive lithocap emanating from an intrusive center. Similar lithocaps host rich epithermal gold systems in some of the world's best mining districts. A pair of graben'forming faults (labeled #6 and #9) identified in the Jurassic volcanic rocks was mapped in detail, surface sampled and surveyed using short-wave infrared (SWIR) instrumentation to define the areas of most intense alteration. This work led to three specific questions to be answered by drilling:

  • Did the graben faults act as conduits for mineralizing fluids?
  • Can receptive units be identified within the volcanic stratigraphy?
  • Is there a preferred direction within the graben and lithocap with potential to host an intermediate sulfidation epithermal occurrence?

Graben Faults

The graben-forming faults were suspected to be significant precious-metal fluid pathways; they were traceable over several kilometers and they projected into the historical Johnny Mountain Mine where they are recognized as controlling gold distribution within the mine. The best indication that these faults helped to focus gold came from an intersection in QR-17-06; here the #6 fault returned a 3.8 meter interval of 6.52g/T gold. Elsewhere in hole QR-17-04, a silica breccia zone adjacent to the #9 fault contained anomalous gold concentrations. We have concluded from these results that the graben-forming faults are likely an integral part of the mineralizing system but are not the primary depositional sites for precious metals at Quartz Rise.

Receptive Volcanic Units

The volcanic stratigraphy established from surface mapping and drill holes shows a series of coarse lithic tuff flows intercalated with densely welded flows, incestuous porphyritic sills and tuffaceous sedimentary rocks. In Quartz Rise, the coarse lithic tuff tends to show much more intense leaching and acid alteration then do the densely welded tuff, sills or sedimentary rocks. In several drill intersections, the tuffs directly below the densely welded units or sills contain intervals of anomalous gold, specifically holes QR-17-2 and QR-17-7. These results indicate that the coarse lithic tuff units were permeable to hydrothermal fluids and could represent permissive units for deposition of precious metals.

Vectoring Towards a New Target within the Quartz Rise Graben

Compilation of surface mapping and drill hole geology shows a clear trend of decreased hydrothermal alteration toward the south and east. This is defined by the intensity of acid alteration, better preservation of original volcanic textures and diminishing pathfinder geochemistry. The opportunity for discovery therefore appears to improve to the north and west of the Quartz Rise area, toward historical mining. Furthermore, it has become evident that the northwest trending graben structural pattern does not account for the best gold values found in this year's program including holes QR-17-01 (1.5 meters grading 8.26 g/T gold) and QR-17-07 (1.5 meters grading 74.1 g/T gold) as well as sampling of a cliff face north of Quartz Rise which returned very high grades ranging from 1.49 to 125.3 g/T gold.

A secondary and subordinate northeast structural orientation has subsequently been defined which is orthogonal to the graben faults and preferentially localizes intervals of high-grade gold. The 2017 Quartz Rise drilling plan was not designed to evaluate this northeast orientation. An IP survey was conducted late in the 2017 program to pursue this idea and its chargeability features provide indirect confirmation of favorable northeast structures which will be targeted in next year's program.

Selected 2017 Assay Data

The results provided in the table above are early stage and insufficient to establish a true thickness of the mineralized zones. These intervals are provided as an illustration of specific environments encountered in the program and do not represent all the precious metal intervals from the drilling program. Additional drilling will be required to determine the relevance of the widths of drill hole intervals reported here.

Historical Work by Previous Operators

Exploration on the Iskut Property has historically focused on either large bulk-minable targets like the Bronson Slope deposit or narrow high-grade gold targets like the Snip and Johnny Mountain mines. During the Iskut Property's more than 100 year history, numerous prospectors, exploration and operating companies have conducted work on the property in piecemeal fashion. With the consolidation of land holdings by Skyline Gold (subsequently SnipGold) a more comprehensive exploration effort became possible for the property. The opportunity now exists to evaluate the property as hosting a series of related mineralizing events with district potential.

Historical work demonstrates that inexpensive geophysical tools and surface sampling technologies are effective for identifying and refining drill targets. In its evaluation of earlier operators' airborne geophysical surveys, Skyline recognized that these tools can help refine targeting on prospective ground. Skyline re-flew parts of the older airborne magnetic and electromagnetic surveys and expanded the survey to cover additional areas. Results from that work identified several prospective targets in the Johnny Flats, C-1 and Burnie areas. Most of these airborne anomalies are now recognized as drill-ready exploration targets with potential for deposits similar to the historical Snip Mine (Figure 1).

Following up on historical surface sampling, Skyline conducted an extensive trenching and soil sampling program on the Bronson trend (Figure 2: Table 1). In conjunction with that work, ground VLF-EM surveys were conducted to refine the Bronson Slope deposit in advance of Skyline's drilling. After completing the 2011 drill program, a borehole pulse electromagnetic survey (BHEM) was undertaken. Results from these surveys have refined the limits of the Bronson Slope deposit area and indicated potential for eastern extensions of the Snip Mine.

Successful use of surface geochemistry on both rock and soil samples in the Bronson Slope and Johnny Flats areas warranted the expansion of this program to several other targets. Additional positive results were obtained in the Johnny Mountain (Figure 3) and Bug Lake (Figure 4) areas. The latter target shows an extensive soil geochemical anomaly around the historical underground mine which remains largely untested by drilling.