seabridge high grase drilling quest results
TORONTO, CANADA--(Marketwire - Sept. 27, 2012) -Seabridge Gold (TSX:SEA)(NYSE:SA) today reported encouraging initial results in its search for a high-grade core underlying its very large KSM gold-copper project, prompting Seabridge to expand and extend the current exploration drilling program. Two targets have generated drill results consistent with a possible core zone target. Drilling has also found additional zones of mineralization which are similar in style and grade to the known reserves.
Seabridge set out this summer to find a core zone with higher gold and copper grades within its 100%-owned KSM property by drilling 11 deep holes on four distinct targets totaling about 7,500 meters (see map below). The program has been modified to reflect results; to date, 12 holes have been drilled including three holes which discovered an unexpected epithermal gold deposit known as the Camp Zone (see release of September 5, 2012).
Seabidge's exploration thesis is that: (1) porphyry deposits are known to have high-grade cores formed under higher temperature and pressure conditions in deeper parts of the system; (2) such a core has not been discovered at KSM; (3) all the available data suggests that such a core exists and that it likely remains intact within the KSM claim boundaries. Drilling at KSM in previous years focused successfully on building reserves higher up in the system. This year, it was decided to focus exploration on potential core zone targets using the vast array of data generated by Seabridge and previous operators.
World-class gold-copper porphyry districts such as KSM usually exhibit links between the deeper, magmatic source ores upwards through transitional volcanic-hosted porphyries and skarn zones to shallow vein systems. The six deposits in the area of KSM display this vertically evolutionary architecture. All four porphyry zones at KSM are open at depth and may link to a deeper source. This year`s program has used the evidence of temperature and pressure variances, geochemical markers and deep penetrating geophysical surveys to vector from known mineralization towards a possible source.
Seabridge Chairman and CEO Rudi Fronk noted that "everything we have learned in the current program tells us that the core should be close to KSM`s existing deposits at a reasonable depth. We are finding the markers that favor a discovery. Both positive and negative results have been helpful in narrowing the search. Although we are quite excited by the unanticipated discovery of the Camp Zone, we are committed to this search for the core zone. It may take more than one season to find the prize but this effort offers the potential to dramatically improve project economics and, in my view, represents an achievable objective for our very accomplished team of geologists. Our entire organization is enthusiastic about the success of the program so far."
Following is a detailed summary of results in the targets tested thus far in the 2012 program:
Priority #1: McQuillan Target
Drill hole MQ-12-02 was collared about 3 km south of the Mitchell deposit, below the Mitchell Thrust Fault on an azimuth of 145° and dip of -55°. The hole targeted a discrete magnetic anomaly down dip of surface alteration and mineralization in the McQuillan prospect area. Altered andesite rocks of the Hazelton Group and coarse grained porphyritic intrusions were encountered throughout this drill hole. After passing through the Mitchell Thrust Fault alteration intensity increases down hole. Below 480 meters, potassium feldspar, biotite and magnetite become the dominant alteration minerals associated with chalcopyrite and pyrite. The drill hole was terminated at 690 meters due to deteriorating conditions on the drill pad.
The alteration mineral assemblages indicate that this drill hole traversed from an environment of lower temperature and pressure into our targeted higher temperature environment. Assays show increasing copper grades within the potassic alteration assemblage but little coincident increase in gold grades. McQuillan is a priority target area to host a high-grade core zone and follow up drilling is ongoing.
| McQuillan Target Assay Results |
| Hole ID | Total
Depth
(meters) | From
(meters) | To
(meters) | Thickness
(meters) | Gold
Grade
(g/T) | Copper
Grade
(%) | Silver
Grade
(g/T) | | MQ-12-02 | 690.0 | 526.7
594.6 | 594.6
652.7 | 67.9
58.1 | 0.99
0.54 | 0.26
0.23 | 5.0
3.7 |
Priority # 2: Kerr Dip Projection
Evaluation of the Kerr dip projection target is still in progress; the drill core from the first hole looks promising but assay results will not be available for several weeks. The dip projection of the Kerr deposit returned a very discrete and high amplitude low resistivity anomaly in the MT survey. Kerr is open at depth and this anomaly provides good support for the dip continuity of the deposit. Observations from the drill core confirm the intense hydrothermal alteration characteristic of the Kerr deposit and abundant sulfide minerals suggest copper grades can be expected in these rocks.
With this encouragement in the first hole, two more are being drilled in the current program.
Mitchell/Iron Cap Lateral
Drill hole M-12-128, drilled at azimuth of 125 and dip of -75°, tested a deep MT low resistivity anomaly between the Mitchell and Iron Cap deposits. It intersected massive andesite and stratified tuff, intruded by several decimeter scale porphyritic hornblende and feldspar monzonite intrusions. The potassic hornfels of the andesite is pervasively chlorite altered, with pyrite, magnetite, and minor but ubiquitous chalcopyrite. A weak stockwork of centimeter scale quartz veinlets occurs throughout. Almost the entire drill hole is mineralized, averaging 0.16g/t Au and 0.11% Cu from 9 to 661 meters. The intrusive rocks are maroon colored due to extremely fine disseminated hematite, but generally not well mineralized. This sequence of rocks is entirely in the panel between the Sulphurets Thrust Fault and Mitchell Thrust Fault. The Mitchell Thrust Fault was intersected at 765 meters, deeper than expected. Beneath the Mitchell Thrust Fault, the hole intersected intense phyllic alteration in andesite with 1 to 2% disseminated and veinlet pyrite, and minor very fine disseminated chalcopyrite and molybdenum to the end of the hole at 828 meters. This alteration mineral assemblage is similar to the upper and eastern fringes of the Mitchell deposit, 800 meters to the south. Intervals above and below the Mitchell Thrust Fault in this hole are pervasively altered and associated with a very large mineralizing system.
Drill hole M-12-129 was drilled at azimuth of 125 and dip of -75° and tested a deep MT low resistivity anomaly in the panel between the Mitchell and Sulphurets thrust faults, approximately two kilometers northwest of the Mitchell Zone. The Sulphurets Thrust Fault was intersected close to the estimated depth at 517.3m. Above the fault are barren sedimentary rocks of the Triassic Stuhini formation. Beneath it the hole intercepted extensive disseminated and veinlet hosted pyrite and chalcopyrite mineralization associated with a well developed quartz stockwork in Hazelton Group andesite. A potassic alteration assemblage including feldspar, biotite, and magnetite transitions to a molybdenite bearing chlorite and quartz dominant alteration assemblage to the end of the hole at 903m. The interval 775-777m contains an oblique cutting quartz vein rich in chalcopyrite and may indicate leakage along a fracture from a higher grade part of the system. The average grade for the interval from 614.6 to 897m (282.4m) is 0.050g/t Au, 0.10% Cu, 0.0046% Mo. The hole ended approximately 150m from the proposed KSM ore and service haulage tunnel route.
The mineralized and altered intervals beneath the Sulphurets Thrust Fault intersected by holes M-12-128 and M-12-129 are interpreted to have intersected the periphery of a new, blind (or buried) porphyry Au-Cu hydrothermal system at KSM. This system will be evaluated as a possible core target and a follow-up drill program will be designed and executed in 2013 if other, higher priority targets are not successful.
| Mitchell/Iron Cap Lateral Target Results |
| Hole ID | Total
Depth
(meters) | From
(meters) | To
(meters) | Thickness
(meters) | Gold
Grade
(g/T) | Copper
Grade
(%) | | M-12-128 | 828.0 | 9.0 | 661.0 | 652.0 | 0.16 | 0.11 | | M-12-129 | 903.0 | 614.6 | 897.0 | 284.2 | 0.05 | 0.10 |
Sulphurets Dip Projection
Three holes tested the dip projection of the Sulphurets deposit and encountered extensive fine-grained thermally metamorphosed hornfel rocks. These fine grained rocks pose challenges in determining thermal or alteration vectors and will be studied in more detail over the next few months.
Hole S-12-75 tested an MT moderate-to-high resistivity feature down dip of the central Sulphurets and Main Copper zones. This hole was drilled at an azimuth of 140°, inclination of -77°. Hornfel andesite volcanic rocks with chlorite-pyrite-magnetite alteration and patchy breccia related silica was encountered down to the Sulphurets Thrust Fault at 354.9 meters. Between 153.7 and 322.65 meters, the volcanic rocks are intruded by porphyritic monzonite dykes or sills comprising close to 50% of the total volume. Small clots and disseminations of chalcopyrite are common throughout, but tend to be concentrated in the volcanic section. Beneath the SulphuretsThrust Fault, the hole entered mineralized rocks of the Sulphurets zone. Host rocks are crackled hornfel volcanic rocks. Projected higher grades down dip of the Sulphurets deposit have been displaced by a fault at 501.8 meters. Alteration and mineralization continue beyond the fault, however composite assay grades from 501.5 to 640.6 are lower than expected.
Drill hole S-12-76 is 400 meters northeast of S-12-75 and tested the same target. The drill hole is orientated at azimuth 145°, inclination of -72°. Thermally metamorphosed volcanic rock with chlorite and potassic minerals ran from the surface down to 93.55 and contained chalcopyrite as fine clots, and disseminations. Barren porphyritic monzonite from here to 320 meters, then poorly mineralized volcanic rock as above the monzonite to the Sulphurets Thrust Fault at 350 meters. Below the fault, chlorite and biotite hornfels andesite was encountered with several barren mafic dykes to the end of the hole. The Raewyn Copper zone was intersected from 468 to 533.15 meters, and grades 0.36g/t Au and 0.29% Cu over 65.15 meters, indicating the limits of the zone.
A low resistivity MT anomaly beneath the Sulphurets Thrust Fault some 2000 meters northwest of the Sulphurets zone was the target for hole S-12-77. It is orientated at azimuth of 145°, inclination of -62°. Black and grey, variably carbonaceous and deformed, clastic sedimentary rocks of the Stuhini group were intersected down to the Sulphurets Thrust Fault at 493.5 meters. Beneath the thrust fault, younger Hazelton sedimentary and tuff rocks transition to massive intermediate volcanic rocks at 634.8 meters. The volcanic rocks are increasingly veined, crackled and contain more intense chlorite-epidote-calcite-pyrite alteration with depth. A major fault was intersected from 768.75 to 777.4 meters beneath which, the volcanic rocks are more intensely hornfelsed and crackled, with variable chlorite-albite-pyrite and silica-pyrite alteration. This is very similar to alteration in the periphery of the Sulphurets zone. The low resistivity anomaly is attributed to graphite in sedimentary rocks and pyrite veinlets in altered rocks beneath the Sulphurets Thrust Fault. The alteration and mineralization indicate this hole may lie at the fringes of a large mineralizing system, which could be distinct from both the Mitchell and Sulphurets zone which are over 2000 meters from this intersection. This new system could be a target for a high grade core. Thermal vectors in these drill holes and historical drilling will be evaluated in order to assign a priority to this target for 2013.
| Sulphurets Dip Projection Target Results |
| Hole ID | Total
Depth
(meters) | From
(meters) | To
(meters) | Thickness
(meters) | Gold
Grade
(g/T) | Copper
Grade
(%) | | S-12-75 | 717.0 | 44.0
100.8
192.0
319.7
366.5
394.0 | 77.0
153.7
294.0
341.8
388.0
555.0 | 33.0
52.9
102.0
22.1
21.8
161.0 | 0.25
0.25
0.32
0.19
1.25
0.41 | 0.18
0.16
0.22
0.20
0.07
0.22 | | S-12-76 | 699.0 | 468.0
683.0 | 533.3
695.0 | 65.2
12.0 | 0.36
0.92 | 0.29
0.02 | | S-12-77 | 900.00 | 631 | 646.0 | 15.0 | 0.72 | 0.02 |
Sulphurets Lateral
Historical targets have been identified 1.2 kilometers southwest and 0.5 kilometers northeast along the projection of the Sulphurets deposit. The southwest target is now referred to as the Camp Zone and the epithermal mineral occurrence in this area is being investigated (see news release of September 5, 2012). The northeast target, the Ice Fields area received two drill holes in this program.
Drill hole IF-12-03 was a test of a low resistivity MT anomaly lateral to the Sulphurets deposit. It was collared below the Sulphurets Thrust Fault at azimuth 145° and dip of -55°. The hole intersected volcanic and sedimentary rocks of the lower Hazelton Group. Alteration is dominated by silica-chlorite-pyrite in veins and breccia zones as both discordant and concordant features. The characteristics of these altered rocks have some similarities to the uppermost portion of the Iron Cap zone, but are not the typical altered rocks of the KSM porphyry gold-copper deposits. Work continues on evaluating this zone.
Hole IF-12-04 was an off-set of hole IF-12-03 to test the same low resistivity MT anomaly. It was collared above the Sulphurets Thrust Fault on azimuth 145° and inclination of -55°. Above the thrust fault the hole encountered a porphyritic intrusion with extensive potassic and silicic alteration, characteristic of the Main Cu Zone. Below the thrust fault was a sequence of volcanic rocks with minor intercalated sedimentary rocks. Silica and fine sericite alternate with potassium feldspar and biotite alteration. Pyrite is common in these rocks with galena and sphalerite which are uncommon elsewhere in the KSM porphyry gold-copper deposits.
High sulphide content and intercalated sedimentary rocks that locally contain graphite are likely responsible for the low resistivity MT anomaly. The style of mineral occurrence described by these drill holes remains uncertain and additional work is in progress; potentially this could represent a higher level system. Results from these holes will be integrated with data from historical drilling to better define a potential target concept and prioritize it for testing in 2013.
| Sulphurets Lateral Target Results |
| Hole ID | Total
Depth
(meters) | From
(meters) | To
(meters) | Thickness
(meters) | Gold
Grade
(grams
per
tonne) | Copper
Grade
(%) | | IF-12-03 | 783.0 | 64.6
180.0 | 78.0
215.0 | 13.4
35.0 | 2.31
0.47 | 0.01
0.07 | | IF-12-04 | 627.0 | 153.5
250.1
358.0 | 228.0
336.0
401.0 | 74.5
85.9
43.0 | 0.54
0.48
0.48 | 0.16
0.02
0.02 |
Kerr Strike Projection
Two holes have been completed on the strike projection of the Kerr deposit to date.
Drill hole K-12-18 targeted an MT low resistivity anomaly on the south side of Sulphurets valley 1200 meters north of the Kerr deposit. Drilled with an azimuth of 125° and dip of -50°. The hole traversed interbedded black to grey siltstone and andesite tuff down to a fault at 192.5 meters. Intense silicic alteration with abundant pyrite was encountered from about 121 meters. Anomalous gold with silica-pyrite alteration is present in these rocks. Below the fault, a porphyritic plagioclase-hornblende intrusion, with minor chalcopyrite, makes up the interval to 489.5 meters. This interval gives way to a sequence of overturned sedimentary rocks with minor tuff similar to those above the fault. Anomalous gold and silver in these rocks correlates to a local shear zone.
A coincident low resistivity MT anomaly and high chargeability IP anomaly were targeted in K-12-19. The hole is 700 meters south of the Kerr deposit, near shallow historical drill holes, orientated at azimuth of 110° and dip of -55°. The hole intersected andesite flow, tuff, and volcaniclastic rocks. Moderate intensity pervasive chlorite-pyrite alteration is throughout the drill hole with pyrite content averaging 4 to 5% from about 35 to 230 meters. Gold and copper values are not significant.
These drill holes limit the lateral extension of the Kerr deposit to the north. Low resistivity anomalies in both holes are formational, associated with higher than expected concentrations of pyrite and graphite. No further exploration along the north strike projection of Kerr is warranted.
Kerr Strike Projection Targets Results
| Hole ID | Total
Depth
(meters) | From
(meters) | To
(meters) | Thickness
(meters) | Gold
Grade
(g/T) | Copper
Grade
(%) | | K-12-18 | 693.0 | 123.0
624.0 | 154.3
644.8 | 31.3
20.8 | 0.34
0.41 | 0.03
0.01 | | K-12-19 | 308.8 | 116.0 | 126.5 | 10.5 | 0.31 | 0.04 |
National Instrument 43-101 Disclosure |
