Board Thread:Theories and Speculation/@comment-3568954-20141110160729/@comment-3531945-20141110162027

Roshi was stated to gained the ability to MIX earth and fire to create lava no just GIVEN lava. Naruto gained the ability to use basic and advanced not just through bijuu but also through the Rikudo Sage mode which granted him the Knowledge and ability to understand the very nature of chakra, hence him using ying-yang release without a bijuu (ref. 4th DB)