Ojos del Salado is a stratovolcano, meaning it's formed from layers of lava and ash. It's generally accepted that stratovolcanoes are associated with andesite magma.

However, it's important to note that:

* The exact magma composition of Ojos del Salado is not well-studied. There's limited research on the specific magma type, and most information is based on observations of surrounding volcanoes and the overall geological context.

* Magma composition can vary within a single volcano. This means that while the dominant magma type may be andesite, there could be instances of other compositions like dacite or even rhyolite in some eruptions.

Therefore, while andesite is the most likely magma type for Ojos del Salado, further research is needed to confirm its specific composition and potential variations.