"The analysts are puzzled why the stock price plunged late last...

"The analysts are puzzled why the stock price plunged late last month from about $2.20 to as low as $1.63."

Well to answer that it may be because the company wanted the share price to drop especially if they want to take out their neighbour in Senegal which is Oromin. The price also dropped by almost the same on the Canadian market.
If they want to issue shares to Oromin shareholders on a takeover they would increase value for current holders in TGZ by issuing shares to Oromin holders based on a lower TGZ shareprice.
Oromin has also dropped 8 cents to 75 cents since mid January.
Expect TGZ to be trading at $1.84ish today seeing it went up on the TSX friday.
Can see this back up around $2.30 really soon based on production stability and hedging disappearance. Far higher is a target if gold itself goes for a run.