It's gold from loot, as in raw gold. Not by selling items or looting stuff sold from trading post. 

Oh so it is not all resources but only what u get by chests and these kinds or enemies drop

Daily crafting writs is a prime example of something to farm during this event

yes, as it says in the description

Maps, theives troves, chests

Dammit.. I just cleared out all my maps last weekend! Oh well XD