(1) Persons engaged in teaching and conducting research in the science of geology in an accredited college or university, and students acting under their direction, but who are not engaged in the public practice of geology in this state;
(2) Officers and employees of the United States of America, practicing solely as such officers or employees; or
(3) A subordinate to a geologist registered under ORS 672.505 to 672.705 insofar as the subordinate acts solely in such capacity. This exemption, however, does not permit any such subordinate to practice geology for others or use the title "registered geologist." [1977 c.612 §4]