** Shares of Great Southern Mining GSN.AX rise as much as 10.7% to A$0.031, highest level since October 29
** Stock log its biggest intraday pct gain since September 30
** Gold explorer says it has found strong gold presence at Amy Clarke prospect, part of its fully-owned Duketon gold project in Western Australia
** Says co completed drilling programme at the prospect in October
** Stock has doubled in value this year, including the day's move
(Reporting by Rajasik Mukherjee in Bengaluru)
((Rajasik.Mukherjee@thomsonreuters.com))