Thus it is only an assumption that only U-238 was present at the beginning. All the granite in the world is time dated by the isolated polonium 218 within it. An underlying problem. Gentry reclassifies granite. According to the evolutionary theory, granite is officially classified as an igneous rock, that is, a rock formed from lava flows.
Molten rock is said to have cooled and formed granite.
But Gentry declares this to be untrue.