Cash had joined the company's board in May 2007 following an 18 month engagement as a consultant advising it in relation to the Perkoa Zinc mine development.
Following a brief period in 2008 when he served as the company's chief executive officer and managing director, Cash was appointed chairman of the board in January 2009.
Blackthorn has been delivering some impressive drilling results, and recently intersected hypogene sulphides including 12 metres at 0.55% copper from 307 metres and 17 metres at 0.42% copper from 399 metres at the wholly-owned Mumbwa Project in Zambia.
In December, the company updated Resources at the Kitumba deposit by 25% to 34.7 million tonnes at 2.29% copper at a 1% cut-off.
This includes a Measured Resource of 10.4 million tonnes at 2.93% copper, or 306,000 tonnes of contained copper.
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