Extending the warrants means that investors that have warrants have more time to execute them, they were scheduled to expire this week. The current market value is lower than expected right now meaning there really isn't any extra value to the warrants to persuade investors to purchase them.
Personally, I was looking to sell some of my existing shares in order to purchase more shares with warrants. This route doesn't really pay off if the executable value is the same as [or close to] the market value.
Also, as far as I know, this summer's exploration plans are already fully funded.