Don't take photosynthesis for granite

Minik Rosing thinks he has found the oldest evidence of photosynthesis yet, in rocks 3.7 billion years old. He had already reported fossil plankton from that era in sedimentary rocks from Greenland and presented radiologic evidence of enrichment by living organisms in earlier papers.

He also thinks photosynthesis may be responsible for the creation of all the continents on earth.

Photosynthesis makes three times as much energy available for geochemical activity as all of the energy that comes from the molten interior. The new date for photosynthesis puts it in a time when there were no continents on earth. Continents are formed from granite, which is less dense than the basalt from which it is made, and on which it floats. Basalt is weathered into clays, and those clays form granite when they are melted.

The vast amounts of energy created by photosynthesis keep the atmosphere and the oceans out of balance with the minerals that make up the earth. This increases weathering, and changes the resulting products of weathering, favoring the formation of granite.

Granite is not found on any planets in the solar system except Earth. Could this be because only Earth has life?