Have a good weight Argentavis (with a saddle, so you can craft behemoth gates) filled with thatch following your golem (on high range works the best) and get wood & stone with the elemental. Transfer the wood & stone you get into the Argentavis and make Behemoth gates. You can also just make other stone stuff, no need for argent but remember to bring thatch!
Rock elementals are extremely tough to kill or knockout. Over encumbering them inside or around your base and setting them to aggressive allows them to defend your base with their rock throw attack without being kited away by enemies.