VANCOUVER, B.C., Oct. 7, 2002 (PRIMEZONE) -- Trivalence Mining Corporation (TSX Venture Exchange:TMI) (OTCBB:TMIGF) is pleased to report diamond results from reverse circulation drilling carried out by its joint venture participant Rio Tinto Mining and Exploration Ltd. ("Rio Tinto") which is conducting exploration on the 1,012 sq. km. Aredor concession in Guinea, West Africa. Rio Tinto can earn up to a 58% interest in any kimberlite developed into a mine.
K14N Kimberlite
Eight holes totaling 858 meters have been drilled testing a geophysical anomaly identified by Rio Tinto north of the known K14 kimberlite. All eight holes successfully intersected kimberlite. An additional four holes totaling 276 meters were drilled testing a zone 100 meters south of K14N testing an area previously sampled by the Russians in the 1960's. Again, all four holes successfully intersected kimberlite. Rock chips collected on site were composited by rock type and texture and then transported to Rio Tinto's Dense Media Separation plant in the village of Keroune 40 kilometers east of the Aredor site. Elevated diamond counts were returned from four holes.
The following grade information is based on the carat weight of stones recovered having at least two dimensions greater than one millimeter and then divided by the dry weight of rock chips processed. Rio Tinto has informed the company that recovery of drill chips from the drilling on K14N and K14A was on average 42%, hence calculated grades may be exaggerated by up to two times on average.
Drill hole RC040 intersected kimberlite from 0 to 95 meters and returned a grade of 0.119 carats per tonne ("cpt") over 95 meters which included intercepts of 0.166 cpt over 14 meters (recovery 17%), 0.337 cpt over 24 meters (recovery 54%) and 0.147 cpt over 13 meters (recovery 86%).
Drill hole RCO41 intersected kimberlite from 0 to 62 meters and returned a grade of 3.124 cpt over 62 meters which included intercepts of 2.973 cpt over 25 meters (recovery 8%), 5.958 cpt over 20 meters (recovery 25%) and 3.870 cpt over 6 meters (recovery 66%).
Drill hole RCO42 intersected kimberlite from 0 to 79 meters and returned a grade of 2.588 cpt over 79 meters which includes an intercept which grades 7.117 cpt over 32 meters (recovery 26%).
Drill hole RCO43 intersected kimberlite from 0 to 38 meters and returned a grade of 1.371 cpt over 38 meters which includes intercepts that grade 1.683 cpt over 23 meters (recovery 22%) and 1.061 cpt over 12 meters (recovery 18%).
Recovery was calculated by dividing the weight of the recovered dry rock chips processed by the expected weight over the same intercepts. Expected weights are computed by multiplying the area of the drill bit by the distance of the intercept then multiplying by the specific gravity of the rock type.
The largest diamond recovered was a 0.889 carat mackle and was recovered in hole K14N RC041, this diamond was not included in calculating the above stated grades. For a summary of the drill holes, please log on to the following website: www.trivalence.com
Rio Tinto has informed the Company that it intends to conduct a large diameter core drilling program on the K14N kimberlite. The program is designed to recover sufficient core to aid in rock classification and grade estimation.
K4 Kimberlites
A total of four reverse circulation holes totaling 552 meters were drilled to test the K4 kimberlite. All holes were successful in intersecting the kimberlite. Nine composite samples were processed by Rio Tinto. No significant diamond counts were returned.
Rio Tinto has informed the company that it intends to test the K3 and K6 kimberlites by reverse circulation drilling. The K3 and K6 are the remaining two kimberlites in the K3, K4, K5, K6 cluster centrally located on the Aredor concession.
K7/19 Kimberlites
A total of ten holes were drilled to test the K7 kimberlite and a single hole was drilled to test the K19 pipe. All holes successfully intersected kimberlite. Samples were composited and processed by Rio Tinto. No significant diamond counts were reported.
Airborne Geophysical Survey
Rio Tinto has informed the Company that it has completed a 4700 line kilometre airborne EM and Magnetics survey over the central and southern portion of the Aredor property. The data obtained will be processed to identify suitable drill targets for the upcoming field season.
Trivalence Mining Corporation is a publicly traded company with two producing diamond mines located in the Republic of Guinea, West Africa, and in the Republic of South Africa. In addition to its mining operations the Company has two advanced kimberlite exploration programs currently underway in the Republic of Guinea, West Africa, and in the Republic of Botswana. Exploration of the two properties is being conducted by its Joint Venture participant Rio Tinto Mining and Exploration Limited.
Waseem Rahman, Director
For further information, contact Warren Robb or Omair Choudhry Phone: (604) 684-2401 Email: tmi@trivalence.com Facsimile: (604) 684-2407 Website: www.trivalence.com Toll Free: 1-888-273-3671
The Company relies upon litigation protection for "forward-looking" statements. The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this Release.