The principles of electron spin resonance (ESR) dating depend upon essentially the same criteria as thermoluminescent (TL) dating, but with ESR the trapped electron population is detected spectroscopically rather than by thermal draining. This ESR study of flints includes a preliminary assignment of electron gain and loss centers and a study of their thermal and dose dependencies. Generally, these centers are stable to at least 325° and may partially be regenerated on irradiation after thermal draining. Initial studies of dose dependency indicate a linear relationship between dose dependency and signal intensity over the range 5-30 krad. Comparisons are made between these results and TL measurements made on the same samples. (See also <b>AATA</b> <i>16-842</i> and <i>18-1583</i>) -- AATA