Kenyon Richard was born in San Francisco and graduated magna cum laude from the University of Nevada, Reno, in 1937. He then joined the E. N. Pennybaker exploration team with Consolidated Coppermines Corp. at Ely, Nevada, as a geologist, and in 1941 he hired Harold Courtright. In 1945, Kenyon and Harold joined American Smelting and Refining Co. in Salt Lake City as exploration geologists. They were destined to become perhaps the most famous and successful team in the history of mineral exploration.
In 1947, Kenyon used leached-capping interpretations to design a drilling program at the Quellaveco prospect in southern Peru, which became a major porphyry copper deposit. Two years later, Kenyon and Harold designed a drill program at Toquepala based on mapping of rock types, alteration, and leached capping that increased reserves from 65 million to 421 million tons. Work by both geologists from 1948-1952 at Silver Bell, Arizona identified two orebodies that led to development of ASARCO’s first open pit copper mine.
These early successes led to a request from ASARCO’s New York offices for Kenyon to outline the components of a systematic porphyry copper exploration program. Kenyon’s 1951 report noted that: 1) porphyry copper deposits could exist unrecognized in well-studied mining districts; 2) limonite in leached outcrops could be mapped and used to identify drill targets; 3) previous drill programs may have missed the chalcocite zones if drilling had focused on outcrops carrying oxide copper; 4) ore might occur in the adjacent wall rocks next to the local intrusion; 5) exploration must be extended under post mineral cover where adjacent to exposure of porphyry copper-style geology; and 6) observations are as important in 2007 as they were when written 55 years ago.
Kenyon’s report also suggested how the complex features of these deposits critical for discovery could be simplified for portrayal on a geological map. In 1953, ASARCO opened an exploration office in Tucson, managed by Kenyon, to focus on porphyry copper exploration with emphasis on fieldwork and good geological maps.
This was followed immediately by the discovery of the Mission copper deposit. Prominent discoveries made during the next twenty years included San Xavier North, skarn ores at Silver Bell, Poston Butte, Sacaton, Santa Cruz, Mineral Butte, and Superior East, all in Arizona; La Caridad, El Arco, and Santo Tomas in northwestern Mexico; and Michiquillay in Peru. Field work was often carried out by relatively inexperienced geologists, proof that the report was an outstanding example of a management system designed for discovery.
Kenyon Richard’s impact on exploration for porphyry copper deposits was enormous. His concepts proved the efficiency and effectiveness of managed exploration that focused on field relationships—concepts that numerous other companies tried to copy. His influence, strongly supported by his friend and colleague, Harold Courtright, on the evolution of ASARCO from a smelting company to a mining company is undisputed, and the discovery record of the Richard and Courtright team, sustained over decades, is unsurpassed.
