The rocks blocking your path are too tough for normal bush whacking. You'll need to find some acid to burn through them. Luckily, the plants of this area may provide such an acid. Complete the puzzle in this zone to find the Acid so you can continue.
Zone Received In: The Rocky Jungle
Previous Quest: Investigate the Caves
Stage 1: Find the Dissolving Acid
Stage 2: Use the Acid
Reward: 330xp (!)
Next Quest: Buried Deep, Pirate Entertainment, The Pirate's Code
Questline: Hunt for the Big Whoop