The Bolo Project
The search for gold is much more than finding the right rocks. The rocks matter, but so do politics, infrastructure, access, workability, and costs.
carlin type gold
Off the Carlin Trend
The Carlin Trend is legendary. This tract of land, just 5 km wide and 60 km long, hosts more than 40 separate gold deposits – and 26 have been developed into mines, which highlights how attractive these deposits are.
One key attraction: Carlin deposits are often big. The 26 mines of the Carlin Trend have to date produced more than 84 million ounces of gold and reserves still exceed 31 million ounces.
Carlin gold can be a bit challenging in terms of metallurgy – the classic deposits comprise very fine-grained sulphide gold that can only be recovered via roasting – but the deposits offer scale and grade that easily overcome this metallurgical hurdle.
Explorers have been searching the Carlin for gold since the original Carlin Mine demonstrated the value in this fine-grained style of mineralization back in 1961. As such the Trend itself has been scoured. However, a host of new discoveries in the last decade have cracked the Carlin’s potential wide open, showing that gold exists in more rock types and settings than previously thought.
Most importantly: it is now understood that Carlin-type deposits exist outside of the trend – if you know what to look for.
And new technologies are aiding the search, helping explorers look under gravels or through post-mineral cover to find deposits that would otherwise be hidden.
The Carlin Trend is the highest concentration of multi-million-ounce gold deposits on the planet. All the major gold companies are active in the trend. And they want to stay active there as long as possible, which means new discoveries are highly desired.
Highly desired means valuable. Take the Long Canyon discovery – after discovering Carlin-type gold at its Long Canyon project in Nevada, Fronteer Gold drilled out __ million ounces of gold before Newmont swept in with a $2.3-billion takeout. Early investors took home __-fold returns.
There are more Long Canyon’s out there, waiting to be found. The best geologists understand that the characteristics behind Carlin-type deposits exist elsewhere in the state.
Carlin deposits only form when a few factors line up: the right kind of carbonate rocks have to be cut by the right kinds of structures and an active, gold-bearing hydrothermal system has to have welled up through those structures.
When these factors line up, a Carlin gold deposit forms. These deposits usually exhibit a slew of similar characteristics:
Northerly-trending structures, usually a northerly trend with high-angle northwest and northeast faults cross cutting
Breccia bodies along the fault structure
Arsenic, antimony, barium, and silver associated with gold
Hydrothermal alteration of carbonate rocks: silicification, iron oxides, sanding texture (from leaching), crystalline barite
Low concentrations of base metals (copper, lead, and zinc)
At Bolo, these characteristics are all present.
The right rocks exist. Where those prospective carbonate layers come to surface, they often appear as iron-stained jasperoids with crystalline white barite. The carbonate rocks in these areas are highly altered and silicified. Where there is gold, levels of barium, arsenic, and antimony are elevated.
In other words, Bolo satisfies all of the Carlin requirements.
The Bolo Project
The search for gold is much more than finding the right rocks. The rocks matter, but so do politics, infrastructure, access, workability, and costs.
The Bolo project ticks every box. The rocks have clear potential: they are the right kind of rocks, are cut by the right kinds of structures, and have returned gold in many samples and drill holes. No explorer has yet unlocked the puzzle and discovered a significant deposit at the property, but where there’s this much smoke there is likely a fire.
As for politics and workability: this is Nevada. Were it a country, Nevada would be the 4th largest gold producer in the world behind China, Australia, and Russia. Since John Livermore and Alan Coope outlined the first deposit on the famous Carlin trend in 1961, the state has produced 225 million ounces of gold. It remains an exploration hot spot for its ongoing gold potential and because the state supports this sector, Nevada is a very workable jurisdiction with a population that understands mining.
Bolo is road accessible; it is crisscrossed with dirt roads. Power passes within 20 km, there is abundant water in the area, and the topography is reasonable.
Easy access in the middle of a mining-heavy state means mining support services abound in the Bolo area. As such, exploration costs are low. A dollar goes a long way at Bolo, which means fewer capital costs and better returns for shareholders.
Bolo is in central Nevada, approximately 290 km southeast of Reno and 295km northwest of Las Vegas. It is very much road accessible, with various dirt roads and tracks traversing the property.
The town of Ely is 192 km northeast of the project and has full services, enough to support a large copper mine. Power lines pass within 20 km of the property. There is ample water in the area, available through negotiation with owners of the water rights.
Much of the project is gentle topography, with gently sloping hills. There are steep sections, but the topography is not challenging for exploration and it would not be a difficult place to design and build a mine.
The property comprises 187 unpatented lode mining claims and 1 patented lode mining claim (the Uncle Sam Patent). There is an active plan of operations that means New Placer Dome is immediately permitted for drilling, though New Placer Dome will have to apply for permit amendments for some of its target areas.
Bolo is in the middle of Nevada, which puts it just south of the famous Carlin Trend. The trend has the highest concentration of Carlin-type deposits but this kind of mineralization exists across Nevada – if you know what to look for.
- Northerly-trending structures
- Altered carbonate rocks with jasperoids, sanded textures, barite, decalcification, silicification, and brecciation
- Associated antimony, arsenic, barium, and -_
- Low base metal concentrations
Bolo has all of these factors. The property has the right rocks and those rocks are cut by two parallel north-trending fault structures. The main Mine Fault has been tracked for 2,750 metres with sample results as high as 8.6 g/t gold. The parallel East Fault is almost as long as 2,200 metres and has generated samples as high as 4.7 g/t gold, despite having seen much less work.
Soil samples, rock and chip samples, and trenches by several iterations of explorers have returned widespread gold at surface. And drilling has shown that gold extends to depth beneath some surface showings. The most recent program, in 2017, returned a best result of 1.3 g/t gold over 133 metres in oxide gold starting at surface. Other strong results include 90m of 1.0 g/t and 52m of 1.27 g/t gold.
The bottom line is that past work has demonstrated that Bolo has all the characteristics of a Carlin-style gold deposit, but the property has not had enough dedicated exploration attention to figure out the puzzle of Bolo’s rocks…that may well contain a good lode of gold.
Gold was discovered in the Tybo District, just 20 km south of Bolo, back in 1865. Bolo itself did not see formal exploration work until 1975, when Chevron completed geochemical sampling and geologic mapping and drilled eight holes. In 1983 another operator, Canerta, undertook further exploration at Bolo, completing several rounds of sampling, mapping, and trenching followed by drilling 18 short holes. A few years later US Minerals Exploration optioned Bolo and completed yet more sampling before drilling seven holes.
All of these programs returned positive results – as in, they all supported the idea that Bolo hosts Carlin-style gold mineralization. They largely focused on the Mine Fault, which is a major north-trending structure within the right kind of carbonate rocks. Those characteristics alone make it prospective for Carlin-style gold, but the Mine Fault also has persistent brecciation, shattering, and silicifiation, along with gold-bearing jasperoids in many places.
Lots of smoke, but none of the operators stayed long enough to find the fire. And it will take some figuring, as the rocks at Bolo are not straightforward. The project sits in a structurally complex part of the Hot Creek Range, which is a hill range within the Great Basin.
The Great Basin is part of the Basin and Range Physiographic Province, an area of north-northeast-trending hill ranges separated by wide flat valleys. In general, the hills are Paleozoic carbonate rocks and siliceous sedimentary rocks.
At Bolo, the Hot Creek Range gets a bit complicated. The western part of the property is predominantly Paleozoic sedimentary rocks while the eastern two-thirds are Tertiary volcanic and sedimentary rocks, which are partly covered by Quaternary alluvial deposits.
The Mine Fault cuts through the property, juxtaposing these two rock types. A parallel structure called the East Mine Fault runs 400 metres to the east. There are additional structures near and running alongside both faults, which is a classic Carlin setup.
The rocks on either side of these faults are tilted, such that the bedding is over-steepened. Where the prospective carbonate layers outcrop, there are often large zone of silicified, brecciated carbonate rocks – jasperoids – with coarse barite. Such jasperiods are commonly associated with Carlin-style gold deposits.
Allegiant Gold and its predecessor Columbus Gold worked the Bolo project for 10 years prior to New Placer Dome optioning the asset, though that time frame included the bear market in precious metals during which time work was limited.
All told, Allegiant collected 708 rock and float chip samples, completed two geophysical surveys, and drilled 67 reverse circulation (RC) holes in five drill campaigns.
Recent work differed from historic work at Bolo in two important ways. First, the work program was guided by Andy Wallace, who is an expert in Carlin gold mineralization. Historic work at Bolo happened when understanding of Carlin-type gold was limited, and Allegiant’s efforts were the first by a modern expert Carlin geologist.
Such expertise led to the realization that the best gold at Bolo is associated with structures that cut the steep bedding at low angles. These structures are likely the result of drag-folding along the Mine Fault. Allegiant began to develop an understanding this geological arrangement, but realized that it require considerably more work than it was prepared to dedicate to the project.
Second reason that set the recent work apart from the historical efforts was that previous operators had focused largely on the Mine Fault zone. Allegiant on the other hand was the first to approach the property broadly, a perspective that outlined seven target zones based on structure, geochemistry, geologic setting, and sampling and drilling results.
The SMF zone has seen the most work of the zones at Bolo. At SMF, the mine fault is apparent on surface through strongly iron-stained soils and gold-bearing jasperoids. Drilling by Canerta and Allegiant tested for gold extending down-dip from surface, with success.
The best rock chip samples from recent work returned 5.18 g/t gold.
Best drill holes:
- BL-23: 30.5 metres 2.38 g/t gold
- BL-4: 18.2 metres of 1.09 g/t gold
- BL-32: 51.8 metres of 0.81 g/t gold
- BL-35: 102 metres of 0.60 g/t gold
- BL-37: 30.5 metres of 0.97 g/t gold
- BL-38: 132.6 metres of 1.28 g/t gold
- BL-39: 89.9 metres of 1.06 g/t gold
- BL-41: 51.8 metres of 1.27 g/t gold
[cross section of South Mine Fault Zone]
Allegiant’s Andy Wallace developed a theory that secondary faults cutting the main Mine Fault at low angles are important drivers for gold in this area, but for corporate reasons Allegiant was not able to test this theory fully. There is good opportunity to grow the known gold zone at SMF through testing these secondary faults and by probing targets in both the hangingwall and footwall that have yet to be tested.
In addition, Allegiant added the Uncle Sam patent to the Bolo project but ran out of time to test the 500 metres of strike between SMF and the new ground. Wallace describes this untested strike extension as “very prospective”.
Located 600 metres north of the SMF zone, the NEX similarly has gold-bearing jasperoids developed along the Mine Fault. The best jasperoid sample to date has graded 3.3 g/t gold. The best drill hole to date came from Chevron, which returned 21.4 metres grading 1.44 g/t gold. Follow-up Allegiant holes returned 25.9 metres of 0.43 g/t gold and 18.2 metres of 1.086 g/t gold.
The FNEX zone has returned 0.64 g/t gold in rock chip samples. Four drill holes in 2013 returned altered limestone and elevated trace elements, but no notable gold.
The Wood Canyon target is 2 km north of the SMF. Jasperoid bodies along the Mine Fault at Wood Canyon have generated samples as high as 1.59 g/t gold. Younger gravels and volcanic tuffs cover much of the carbonate rocks at Wood Canyon, which makes exploration more difficult. Drilling is needed to see through the cover and test for down-dip extensions of the mineralized jasperoids on surface.
The East Fault zone is about 400 metres east of and runs parallel to the Mine Fault. Along the EFZ there are two areas with elevated gold where carbonate rocks outcrop. The southern such area has a jasperoid cap, which Chevron, USMX, and Allegiant all drill tested; those holes did not return the gold values at surface, but the southern zone is far from fully tested.
The northern area has elevated gold in soil and in chip samples, but has not been drill tested. In particular, the north end of the EFZ is very interesting.
The Northeast Fault zone sits 1200 metres north of the East Fault zone. Post mineral gravels and volcanics conceal the prospective carbonate rocks, but where they are exposed there is elevated gold in barite-veined jasperoid bodies. There is an east-dipping fault; the drill target is the projected down-dip extension of the surface carbonates in the footwall of the fault zone.
Three holes drilled in 2013 failed to return gold but did return elevated trace elements and barite.
The Uncle Sam area was added to the Bolo project in 2016 (?). Allegiant drilled six holes into Uncle Sam targeting a major structure that parallels the South Mine Fault to the west. They intersected varying widths of probable fault zone, strongly silicified and decalcified with variable quartz veins and local brecciation.
The best drill result came from hole 55, which cut 21.3 metres grading 0.748 g/t gold. All but one of the other holes returned shorter intercepts of similar or lower grade gold. Some carried good silver, such as 10.7 metres grading 172 g/t silver. Higher silver grades at Uncle Sam fit the model: Uncle Sam is lower elevation than South Mine Fault, which puts it lower in the system where more silver is expected.
Uncle Sam is the newest part of Bolo and has seen very little modern work. The South Mine Fault zone is 500 metres to the north and the strike between remains essentially untested. The strike extent to the south is also almost untested.
The two geophysical surveys – a ground magnetics survey and a CSAMT survey – did not highlight strong geophysical targets, but that comes with two caveats.
First, Carlin-type deposits do not always generate such results. The surveys did, nevertheless, indicate the possible presence of several new structures. Since structures are key to Carlin gold mineralization, these structures deserve to be tested.
Second, other surveys would be more appropriate to test this system. Barrian plans to run a ground IP and a modern magnetics survey, which together should give a deep, 3D image of structure and stratigraphy at Bolo to a much higher degree than has ever been done before.
Phase 1: Bolo Work Program - Add to Prior Success
Geophysics + Sampling + Drilling = Results
- $500,000 USD work program underway – Started April 7, 2019
- Drone flying, imagery interpretation & analysis
- Ground IP and magnetic geophysical surveys for deep penetrating 3D analysis
- Grid soil & rock geochemical sampling across anomalous areas
- Confirm drill targets & finalize summer RC drill program targets
- Secure drill rig and contractor
- Begin 1,800-meter expansion & new target RC drilling program
- Secure lab for drill assays (ALS Global – Reno, Nevada)
- Estimated results in Q4/2020 and Q1/2021
The Project Deal
New Placer Dome is earning ownership of the Bolo project via an option agreement with Allegiant Gold. The first step is earning 50.01%, which requires:
- Exploraiton spending: US$500,000 in 2019, US$750,000 in 2020, US$1.25 million in 2021, and US$1.5 million in 2022.
- Payments to Allegiant of New Placer Dome shares equal to US$1 million, in four equal annual payments
- Honouring the 2% net smelter royalty to Cordex
Once New Placer Dome earns its 50.01%, it can choose to increase its stake to 75% by
- Spending another US$4 million on exploration within four years
If New Placer Dome does not meet the additional earn-in requirements, it must relinquish 0.02% and form a joint venture with Allegiant.