That prominent light colored band caught my eye too. So... searching "geology Cuernos del Paine",
it turns up this from Wikipedia:
Torres del Paine National ParkOrogenic and erosional processes have shaped the present-day topography, glacial erosion being the main one responsible for the sculpturing of the massif in the last tens of thousands of years. A good example of the latter are the Cuernos del Paine, whose central bands of exposed granite strongly contrast with the dark aspect of their tops, which are remnants of a heavily eroded sedimentary stratum. In the case of Las Torres, what once was their overlying sedimentary rock layer has been completely eroded away, leaving behind the more resistant granite.