The Kolo kimberlite pipe is located approximately 60km, by road, southwest of Maseru. The project may be reached by main tar road with a small 4km dirt road leading to the Kolo kimberlite. The journey time from Maseru to site is approximately 45 minutes.
The project area is located in the lowlands of Lesotho approximately 1,500m above sea level, and experiences a relatively mild climate. Climatic conditions are significantly less harsh than in the highlands. The average annual rainfall is 600-800mm and generally falls within the summer months of October to March.
The mild climatic conditions, reasonable annual rainfall (suitable for dam water storage) and proximity to the international airport and Maseru are all positive factors for the Kolo project.
The Kolo pipe has a surface area of approximately 1.2 hectares and intrudes Karoo sandstones of the upper Beaufort and lower Stormberg groups and a late Karoo dolerite dyke. The pipe is therefore Cretaceous in age. The pipe outcrops on a topographic rise and benefits from downslopes on several sides, which will reduce the waste:ore strip ratio of an open pit.
The pipe is an irregularly-shaped body, elongated in a NW-SE direction. The NW and SE lobes comprise softer more weathered kimberlite with a higher country rock and mantle zenolith content than the central more resistant kimberlite.
Past work has shown that the softer kimberlite has a significantly lower grade then the central portion( possibly due to the greater dilution by country rock zenoliths) but both types have a similar rock chemistry. If the Karoo sequence was originally at a similar level to that in the Highlands then a significant amount of erosion of the original pipe has taken place due to the Karoo erosion (at least 2km). This being the case the current pipe level is probably in the lower diatreme phases.
