Vladimir Grib Diamond Mine Image credit: AGD Diamonds
Twenty-four years ago, on February 19, 1996, there occurred an event which later turned to be of key significance for the development of AGD DIAMONDS, JSC – explorers found a kimberlite pipe, which later was named after Vladimir Grib, an outstanding geologist, who worked in Arkhangelsk.
To perform targeted exploration for diamonds, the geological team working in the Arkhangelsk Province at that time developed a set of forecast-and-exploration methods and the Enterprise Work Program for 1992–2000 based on it. The geological service of PGO Arkhangelskgeology (now AGD DIAMONDS, JSC) identified the most promising area within the Verkhotinskoye Kimberlite Field and substantiated the feasibility of exploring this area for diamonds.
Before commencing the licensed operations on the Verkhotinskoye Field, Arkhangelskgeology carried out a geological survey and a set of specialized prospecting works for diamonds, during which it verified 58 magnetic anomalies by drilling and discovered eight pipes of weak diamondiferous kimberlites.
Based on the results of the analysis of geological and geophysical materials, it was decided to re-survey several previously covered areas, including Aeromagnetic Local Anomaly 441. In 1995, the geological team performed another series of ground magnetic surveys and cross-sectional electrical exploration on Anomaly 441. In the course of processing ground-based magnetic measurements using the “sliding window” method, geologists identified a low-contrast local anomaly with a deep-seated object.
On February 19, 1996, they drilled a confirmatory well, No. 441/1, one hundred meters south of the magnetic epicenter of the anomaly and crossed sand-and-clay rock of brown color with small inclusions of tufogenic material at a depth of 69 meters, under the thickness of the Quaternary and Middle Carboniferous deposits. A sample taken from these rocks and then analyzed in the AGD DIAMONDS laboratory produced diamond satellite minerals and 20 small diamonds.
Further drilling of this well yielded kimberlite tuffs, which clearly proved the discovery of a new diamondiferous pipe. In November 1996, the Verkhotinskoye Deposit was officially given the name of Vladimir Grib in honor of the former chief geologist of AGD DIAMONDS, who made a decisive contribution to the discovery of the Arkhangelsk diamondiferous province. Vladimir Grib passed away on December 25, 1995, less than two months before the discovery of this pipe.
Detailed exploration of the diamond field in 2002-2004 was carried out by the Verkhotinskaya Exploration Team. The main task was to study the middle and deep levels of the diamond field. According to the exploration results obtained in 2005, the State Reserves Committee of the Russian Federation approved diamond reserves to a depth of 1,010 m. Thus, the diamond pipe named after Vladimir Grib officially received the status of an industrial diamond field.
It should be recalled that the commissioning of the Grib Mining and Processing Division took place in June 2014. The Grib Mine, which is being successfully developed by AGD DIAMONDS, is the fourth largest diamond field in Russia and the seventh in the world in terms of reserves. And it is the largest diamond asset on the planet commissioned in the last ten years.
