Positive drill results at Kweneng diamonds
Pangolin Diamonds Corporation updated on recent activities at its various projects in the Republic of Botswana, Africa. Its’ key highlights says, 1: Positive drill results at Kweneng, 2: 5% of chromites recovered from soils at Kweneng indicative of diamond stability field & 3: 68 aeromagnetic targets identified at Motloutse and Malatswae.
Kweneng:
Drilling intersected a shallow (< 1 m overburden) phlogopite and clinopyroxene rich ultramafic hypabyssal dyke of approximately 6m in true width. Processing of 25 kg drill chips through Pangolin’s in-house 1 TPH DMS plant produced chromite, clinopyroxene, and what is interpreted as fragments of a chromite-garnet peridotite. The Kweneng Project is located about 20 km north of Botswana’s capital, Gaborone.
This discovery came on the back of an extensive soil sampling program that identified a chromite anomaly measuring approximately 850 m x 250 m. Based on the indicator distribution and the relative location of the dyke, it is expected that more dykes may be present in the area.
Dykes have been mined in South Africa for diamonds to depths exceeding 1000 metres below the surface. Significant diamonds mines have been established on the Bellsbank, Bobbejaan, Ardo, Helam, Roberts Victor, Star and Klipspringer dykes. Economic kimberlite dykes normally average 60 cm – 80 cm in width and tends to maintain their width and grade with increasing depth.
Chromites have been identified as diamond inclusions in West Africa, Dokolwayo in Swaziland, the five mines in Kimberley, Roberts Victor Star (all in South Africa), the Diavik kimberlite in Canada and Murowa as well as River Ranch in Zimbabwe.
52.5% of chromites analyzed were classified as being derived from a “diamond friendly” environment in the mantle. 1: 23% classified as CR DI; Chromite with major element diamond-inclusion composition, 2: 5% classified as CR DI; Diamond-Inclusion Chromite from favorable harzburgite source.
The significance of chromites in diamond exploration was recognized in a publication by Griffin et al (1991) where it was stated, “The high proportion of chromites as inclusions in diamonds from the producing mines in Siberia suggests that disaggregated chromite peridotite can make a major contribution to the overall diamond content of at least some kimberlites.
Diamond inclusions also show that important contributions from chromite bearing rocks have occurred in West Africa, at Dokolwayo in Swaziland, at the five mines in Kimberley, at Roberts Victor and at Star (all in South Africa). No doubt there are many other examples.”
Subsequent to this publication, chromites have been identified as diamond inclusions in the Diavik kimberlite in Canada and Murowa and River Ranch in Zimbabwe.
