The choir and chancel do not stand on the island's granite core but on a platform formed by three crypts, with the massive columns of the Crypte des Groseiliers doing most of the work.
Nothing ever stands on the island's granite core.
mnli hypothesis: Nothing ever stands on the island's granite core. premise: The choir and chancel do not stand on the island's granite core but on a platform formed by three crypts, with the massive columns of the Crypte des Groseiliers doing most of the work.