Anthony R. D. Porter, Contributor

During the islandwide search for bauxite in Jamaica in the 1940s and '50s, the early explorers quickly discovered that the red to reddish brown ore occurred exclusively on the surface of the white limestone formation (since renamed the white limestone group). It was subsequently ascertained by field and laboratory work that the best and most economic grade resided in five parishes, namely, Manchester, St Ann, St Elizabeth, Trelawny and Clarendon. Today, most of the accessible ore in Clarendon has been mined and refined, while Trelawny is yet to be touched.

At 9:00 p.m. on Sunday, April 29, CVM-TV aired a locally produced documentary entitled Cockpit Country: Voices from Jamaica's heart, which sought to highlight the fears and concerns that the people of the Cockpit Country have with respect to the possibility of bauxite mining at some future date. The next day several persons contacted me to ask three things: Had I seen the show? Did I know how much bauxite existed in the Cockpit Country? Could I comment on how much ore remains to be mined in the other bauxite-bearing parishes? I told them to direct the latter two questions to the state-run Jamaica Bauxite Institute (JBI), which has overall responsibility for regulating and monitoring bauxite mining and alumina refining activities.

In recent weeks, the matter of the life expectancy of the island's bauxite reserves has once again been raised, this time by the newly elected Member of Parliament for Central Manchester, Peter Bunting, who was reported to have said at a Manchester Chamber of Commerce forum in Mandeville, on October 4, that the reserves are now set to last another 20 to 30 years. The significance of this statement has not been lost on several citizens of Manchester, nor on the Manchester Parish Development Committee, which seeks to establish an action plan for the development of the parish over the next 25 years and beyond. In order to formulate such a plan, one of the questions being asked is: When are the remaining unmined reserves in Manchester parish likely to be exhausted based on the current extraction rates of Alpart, Jamalco, and Windalco?

While commending Mr. Bunting for wanting to have a frank discussion on the future of the bauxite industry, many persons are hoping that he and the new Minister responsible for Mining, Mr. Clive Mullings, will be able to clear up the conflict that currently exists (based on the published statements quoted below) with respect to Jamaica's remaining bauxite reserves (the international mineral resource classification for which is 'measured' (i.e. proven), 'indicated' (probable) and 'inferred' (possible) - on a parish by parish basis.

Various bauxite reserve estimates

1). May 2004. Chairman of the JBI, Dr. Carlton Davis, estimated "the existing reserves of bauxite ore to be about 700 million tons, just under half of the 1.5 billion tons of reserves estimated at the time of the Bauxite Levy negotiations in 1974" and this was equivalent to "only 50 years of bauxite life" (The Sunday Gleaner, May 23, 2004, page A1).

2). In 2006, the Mona Institute of Applied Science in an article on 'Jamaica's bauxite and alumina enterprise - History of the industry' published in The Gleaner, (Thursday, May 4, 2006) had this to say: "Proven reserves presently exceed 2,500 million (metric) tonnes of bauxite, while processable reserves may amount to 1,500 million tonnes." (The Gleaner, Thursday, May 4, 2006). The same article goes on to state erroneously: "There is no overburden covering the bauxite, as is the case in many other countries."

3). Early in 2007, The Observer quotes the general manager of the JBI, Parris Lyew-Ayee, is quoted as having said that "bauxite mining will end in 50 years, at current production levels, if the reserves are carefully utilized" (The Sunday Observer, February 11, 2007, Section 1, page 7). According to data released by the JBI, some 15 million tonnes of bauxite were produced in 2006. [Authors note: At this rate of production, some 750 million tonnes of recoverable (i.e. net of any losses due to mining, etc.) and treatable (i.e. processable in the refinery) bauxite ore will be required to achieve this 50-year target].

4). In the same article, the president of the National Workers Union, Vincent Morrison, is quoted as saying that "based on information available to him and from investments now under way in the sector, bauxite will be mined in Jamaica for another 45 years at least, and possibly up to 100 years."

5). Then earlier this month, as noted above, Mr. Bunting predicted a life expectancy of 20 to 30 years. But, to which of the parishes does this estimate apply?

Technical considerations

A fact that only a few persons are aware of is that Jamaican bauxite is the most chemically complex in the world, and that the quality of the ore can vary considerably from one parish to another; from one geographic district to another; from one deposit to another; from one limestone host rock to another; and from one topographic elevation to another. Furthermore, of great economic importance is the fact that some bauxites (e.g., the gibbsitic or trihydrate variety), can be processed at low temperature (about 143 ^oC), whereas a higher temperature (around 240 ^oC) is needed to process the boehmitic or monohydrate variety: and, Jamaica has both types.

Consequently, it is absolutely essential for each bauxite alumina company to take these factors into consideration when evaluating the tonnage and grade of its reserves, and preparing its short and long term mining plans. And it is equally important in my view for there to be complete transparency on the matter of parish reserves and life expectancy timelines, so that bodies, such as the Manchester Parish Development Committee, can begin to seriously plan for the day when bauxite mining and refining will be a thing of the past in central Jamaica.

Anthony Porter is a veteran exploration geologist and author of 'Bricks and Stones from the Past: Jamaica's Geological Heritage'.

When are the remaining unmined reserves in Manchester parish likely to be exhausted based on the current extraction rates of Alpart, Jamalco, and Windalco?