Thera is also of special interest to geologists owing to its remarkable volcanic phenomena.
In the African portion Ruwenzori is regarded by some geologists to be a block mountain or horst.
PRE-Roman Britain Geologists are not yet agreed when and by whom Britain was first peopled.
A few geologists regard the sedimentary rocks here classed as Keweenawan as Palaeozoic; but they have yielded no fossils, and are unconformable beneath the Upper Cambrian, which is the oldest sedimentary formation of the region which bears fossils.
Naturalists will of course prefer other limits according as they are geologists, botanists or zoologists.