The Lawyers Project Is Located In The Prolific ‘Golden Horseshoe’
The Lawyers Property covers 144 km2 of highly prospective rocks in the northeastern region of the prolific metal-endowed Stikine Terrane, British Columbia, Canada. Magmatic events in Stikine during the Late Triassic and Early Jurassic were the driving source for the development of mineralizing porphyry and epithermal systems. On both the east and west sides of the Bowser Basin the same magmatic and mineralizing events are recognized (Logan and Mihalynuk, 2014), forming an arch of gold and polymetallic mineralization; which is depicted herein as the ‘Golden Horseshoe’ which includes the Golden Triangle (Figure 1).
Figure #1 – Map of the Golden Horseshoe
The Lawyers Project straddles an important stratigraphic horizon between rocks of the Upper Triassic Stuhini Group and Lower Jurassic Hazelton Group that define an important geological unconformity with many of the deposits in the Golden Horseshoe concentrated along it. The project is also located in a proven and profitable mining jurisdiction, only 45 km northwest of the Kemess gold-copper mine (Figure 2). The Golden Horseshoe provides a visual context for the mines, discoveries and common geology of the Golden Triangle and Toodoggone regions, which forms a prolific metalliferous arch that includes the Quesnel and Stikine terranes.
Figure #2 – Project map with local infrastructure
Exploration on the Lawyers property and the surrounding area began in the late 1960s and peaked in the 1980s, identifying numerous showings, prospects and deposits culminating in the development of the Lawyers gold-silver mine that operated from 1989-1992 and produced 171,200 oz gold and 3.6 million oz silver over the 4-year period. The deposit was never fully mined, or the surrounding area thoroughly explored for gold-silver mineralization. An estimated $50 million in infrastructure remains on the property, including year-round road access.
1980 vs 2020
At the heart of the Laywers Trend is the structurally controlled Cliff Creek, Dukes Ridge, Phoenix, and AGB zones that are located within a large 5 km by 8 km radiometric anomaly that is coincident with potassic alteration, associated with a low-sulphidation epithermal system (Figure 3). The limited historical underground production at the AGB and Cliff Creek zones targeted the high-grade veins associated with this large epithermal system. However, recently acquired data, geological compilation, and reinterpretation has revealed significant potential to add gold and silver ounces within these zones and across the entire mineralizing system. New drill results are providing previously unrecognized bulk-tonnage, near-surface intercepts that envelope the higher-grade intervals of gold and silver mineralization. These results are from within the footprint of the historically mined areas, but also include significant gold-silver intercepts along strike, and at depth. The surface expression of the mineralization is coincident with pervasive potassic alteration, large gold-in-soil anomalies, and anomalous rock and trench results.
Select high-grade drilling intercepts from the Lawyers Trend include:
259.76 g/t Au & 3,320.3 g/t Ag over 3 m*
108.36 g/t Au & 911.2 g/t Ag over 7 m*
86.06 g/t Au & 583.83 g/t Ag over 7 m*
52.02 g/t Au & 846.44 g/t Ag over 3 m*
12.67 g/t Au & 143.39 g/t Ag over 28 m*
Select bulk-tonnage drilling intercepts from the Lawyers Trend include:
6.96 g/t Au & 254.70 g/t Ag over 57.9 m*
5.76 g/t Au & 128.65 g/t Ag over 33.53 m*
4.06 g/t Au & 409.06 g/t Ag over 40.9 m*
3.78 g/t Au & 82.40 g/t Ag over 35.0 m*
2.68 g/t Au & 82.57 g/t Ag over 36.5 m*
*Drill hole length
** Based on limited information from historical mine level plans and ore block models parts of the results above have been mined. However, both high-grade and bulk-tonnage drill intercepts and surface mineralization extend beyond the known workings and the system remains open along strike and at depth.
The Lawyers property is predominantly underlain by a shallow northwest-dipping sequence of volcanic and sedimentary rocks of the Lower Jurassic Toodoggone Formation (Figure 3), part of the Hazelton Group that is exposed throughout the prolific metal-endowed Stikine Terrane. The Toodoggone Formation can be divided into upper and lower volcanic cycles as illustrated on the simplified stratigraphic column in Figure 4. The Lawyers property is predominantly underlain by lower cycle rocks comprised of thick sequences (>300 m) of dacitic and andesitic tuffs and flows. These volcanic strata erupted concurrently with the development of deeply rooted faults that focused both magmatism and mineralization (Figure 3). Magmatism is expressed as the Black Lake intrusive suite that outcrops in the southern region of the property (Diakow et al., 1993). Locally Asitka and Takla Group rocks are exposed along the margins of the Black Lake intrusive and are in part fault bounded. Similar relationships are often observed in the southern Toodoggone and spatially associated with porphyry style mineralization, including at Kemess.
Localized conglomerates and volcaniclastics within the lower cycle are confined within blocks dropped by steeply dipping syn-volcanic faults and can potentially be used as a vector towards epithermal mineralization. The entire Toodoggone Volcanic sequence is unconformably overlain by the younger Sustut sediments.
Figure #3 – Geological map of the Lawyers property and accompanying cross sections showing the relationship between structure, stratigraphy and epithermal mineralization across part of the central Lawyers Trend.
Figure #4 – Simplified stratigraphic section for the Lawyers project and the broader Toodoggone region. The different types of intrusive rocks, mineralization, and the time period for which they span is illustrated on the right side of the diagram.
The lawyer’s property has undergone a relatively simple brittle deformation history of syn-volcanic graben development and subsequent strike-slip deformation. The most dominant structural features on the property are a series of well-developed NW-NNW (310-340°) striking faults that are subvertical to steeply SW or NE dipping. They typically show evidence of normal displacement with localized, late, strike-slip reactivation. These are the oldest structures on the property and represent syn-volcanic growth faults that formed during Lower Jurassic extension and block faulting.
The orientation and characteristics of the mineralized zones within the Lawyers Trend are consistent with the development of robust hydrothermal systems within a pre-existing NW-NNW trending fault and fracture system. This system is likely reflecting the original volcanic basin geometry, and these structures acted as a conduit for fluids to migrate and precipitate metals. The NW structures and associated mineralization are locally offset by E-W and SW-NE trending strike-slip faults, typically with less than 10 metres of displacement. The structural relationships observed in outcrop and drill core are also observed in the magnetic data, providing numerous new exploration targets.
Volcanic strata on the property are only very weakly altered and original textures are generally well preserved. Narrow localized zones associated with mineralization in the main zones do show intense silicification and potassic alteration. While a variety of alteration is observed across the property, ranging from a massive advanced argillic zone north-west of Cliff Creek to the strong quartz-sericite-pyrite alteration concentrated along structures in the Marmot area. The alteration, variation and zonation suggest that the epithermal mineralization on the Lawyers property was part of a large-scale hydrothermal system.