by Kirsten Günzel, Manager at Günzel Drilling
When a very perplexed geologist could not wrap his mind around a theoretical conundrum involving two nondescript outcrops showing some slight hint of faded oxidized copper, he did not rest until his associates agreed to fund the drilling of a few diamond core holes. After spending two years mulling over it, he realized drilling was the only way forward.
It helped, of course, that the junior explorer with whom the geologist worked shared his interest in exactly such unobtrusive, possibly overlooked, prospects. Nevertheless, the adverse setting within which the campaign was planned and prepared certainly demanded perseverance and the strongest resolve, especially as from the outset it was clear that any deposit such drilling work produced would be marginal at best.
However, the promise of a sound understanding of the target, and in turn the improved ability to infer the potential of other, similar, geological anomalies, weighed in favor of investing in a few holes on a strike running some few hundred meters along a mountainous ridge.
This is the account of a rather peculiar drilling venture in a remote part of North-Western Namibia, an area known as Kaokoland.
Surmounting obstacles and challenges
While the obvious deterring factors included the usual obstacles any exploration drilling project faces – such as budget limitations and the high-risk nature of most exploration activities, the Kaoko project confronted the additional difficulty of being in an exceptionally remote area, characterized by rugged, and at times, inaccessible terrain.
Another very concrete challenge that had to be overcome was to earn the support of and permission from the local communities to work on their land. Additionally, for an environment as pristine as North-Western Namibia, stakeholders are certainly not limited to the local people but include conservationists, anthropologists, and businesses, such as tourism operators. Such parties are at times fiercely opposed to exploration and mining activities, arguing against their social and economic legitimacy in favor of less destructive and extractive land-uses in such relatively untouched regions.
Before tackling tricky geology in a remote area, a worried financier had to be kept on board, permits had to be obtained from relevant government ministries, while conducting sincere communication and ensuring the inclusion of stakeholders, most importantly the semi-nomadic Himba residents of the area. But the doggedness of the geologist and his team eventually paved the way for the drilling work to commence.
Drill plan
The drill plan targeted two locations, firstly in the area of the mysterious outcrops bothering the geologist and secondly, since the rig was in the area anyway, another anomaly roughly 10 km (6.2 mi) east.
The instructions for the recruited core drilling outfit, Günzel Drilling, were to bring 150 m (492 ft) of N-size rods, and a maneuverable coring rig. The number of holes and estimated total meterage were not specified in the scope of work, as all depended on the outcome of the first holes on that virgin ground. The outset made it clear that it would not be a massive project.
Into the field – at seven km an hour
So, during the last week of June 2023, up they went into the wilderness of the north-west, an area of breathtaking natural beauty with endless mountain ranges and valleys of contrasting shades of ochre, populated only by semi-nomadic cattle and goat herders.
In actual kilometers, within the context of vast Namibia, the destination was not notably far, and although the geological team did an exceptional job to create some sort of track, parts of the route remained a challenging offroad 4×4 trip, heavy on vehicles and at times difficult to maneuver. As a result, for the entire trip getting to the site took an exasperating 34 km/h (21.13 mph) on average, of which the final 25 km (15.5 mi) alone took four hours.
As the very vague scope of work did not really help to prepare for the drilling work in an area far removed from standard access to supplies, physical infrastructure and commercial conveniences, the packing list included items for any eventuality. This meant starting with 60 NT rods, 1.5 m and 3 m (5 ft and 10 ft) core barrels, various types of bits and drilling consumables, as well as a selection of spare parts greater than the average supplier might stock. Then there was the food and drinking water for the crew. By packing everything that might be needed, including the kitchen sink, the drillers hoped to avoid any reason for rushing back for a spare bit or a few onions.
The rig selected for the work was a track-mounted Atlas Copco CS1000. While the tracks were the main reason for the choice of a rig, it is also quite compact and can be loaded on a short-wheel base 4×4 lorry. Long-wheel base trucks or trailers would not have been able to navigate the access track’s gullies and narrow ridges.
Drilling begins
The first hole was collared about 25 m (82 ft) off the outcrop, dipping at 55ᵒ. The drill pads were set up very tight on steeply sloping terrain, which made work quite uncomfortable with hardly room to stack the 3 m (10 ft) rods, let alone retrieving a 3 m inner tube without sticking it into the rock face.
As it is so often the case when truly prepared for every event, no such eventuality takes place. Casing to stabilize overburden could be placed at 6 m (20 ft). While over the entire hole the rock remained fairly broken and hard to very hard, the critical aspect of sample recovery was relatively straightforward and overall, the drilling held no surprises. There was little risk of core spin or washing away of soft materials and the formation allowed for a very good sample.
The turnaround time of the 4×4 truck carting drill water was three and a half hours, but fortunately, water loss was not excessive.
On the other hand, rig moves and drill platform preparations were a different matter. Most of the time working was spent on the squeezing of the rig, crew, and equipment through another gulley towards the next collar rather than drilling. In fact, of the 47 shift hours on site, only about 23 involved actual drilling.
Of course, no project ever runs without at least one crisis. This time it was the cook forgetting to pack a ladle. The frustration of the hungry crew having to dish up the evening stew with a teaspoon or fork resulted in quite some vocal discontent. The mechanical department had to save the day with some impromptu grinding and welding.
Results
From the start, the geologist was realistic that any ore found at the location would not offer high promise. Even so, the dire results of the first hole on the most enticing spot, must have come as a bit of a disappointment. Over not even 30 m (98. 4 ft), the sample turned from overburden into some sedimentary formation, switched into a bit of unconvincing host rock and then ended in basement – and that was that. What was worse, the core did not give the answers the geologist came there to find.
When the second hole, again placed just off the second outcrop on the strike, yielded similar results with even less answers, the rig was moved back north along the strike, to where a crack and a fold caused a slight twist in the ridge.
And finally, here it was: the resolution to the riddle of the origin and fading of the bit of copper that could be seen on surface. Giddy with fresh ideas about how to redefine his geological model of the deposit, even if most probably unviable or marginal at the very best, the geologist sent the rig to the other target. Smooth drilling and good core yielded results of no real economic or theoretical interest and concluded a very short drill campaign.
Was it worth it?
Overall, the drilling contractor travelled a total combined 6010 km (3734 mi) to spent five days drilling four diamond holes, totalling 106.25 m (348.59 ft).
In a time when exploration and mining companies are no longer evaluated only by the economic result they deliver to shareholders, but increasingly in terms of their carbon footprint, ESG score and, most importantly, required to meet high social legitimacy standards, a project such as this blitz drilling campaign seems hardly worth the effort, especially since from the outset optimism for the economic viability of the deposit was muted.
Whether at the end, the material expenditure, physical effort and social investment did pay off probably depends on who answers. To the geologist, the few core holes certainly provided the key to his riddle and allowed him to give sound advice to the exploration company regarding any future exploration activities in the area, even if such advice was only to keep any expenditure tightly capped. For the drilling crew, the privilege to have worked in and experienced beautiful Kaokoland was certainly worth the trip, even if for five days only and without proper tableware.
For more information visit: www.guenzeldrilling.com
