Dictionary:Geologic, geological

The Oxford English Dictionary says, ‘‘There is now a slight distinction between the use of geologic and geological: the former tends to be used only as an epithet of things forming part of the subject matter of the science: we may say a geologic epoch, but hardly a geologic student, a geologic history.’’ My personal preference is to use whichever word sounds best depending on what it’s associated with; thus I would write ‘‘seismic and geologic data’’ and ‘‘geophysical or geological data.’’