The geology of Maker is not noticed by Doctor Boase; but it is
obviously the same as that of the adjacent parish, Rame, which Doctor
Boase says is composed in great measure of red and greenish grey
slate, enclosing two and three beds of compact quartzse rock. They are
all similar to the formations in St. Anthony, and in the cliffs under
Mount Edgcumbe and at Saltash; but whether they belong to the
calcareous series or to a more recent one, associated with the
fossiliferous limestone of Plymouth, remains to be ascertained.