Abstract
SUMMARY: Three cores were taken from the deposits of Llyn Clyd and two cores from Llyn Glas, using a Mackereth corer. Samples taken at approximately 10 cm intervals have been analysed for pollen and diatoms. Pollen analysis has been used as a means for correlating deposits in the two tarns. The data show that changes have occurred in the diatom flora of both tarns but these changes are less pronounced than in some lowland bodies of water. Llyn Glas appears to have had more stable conditions throughout its development than Llyn Clyd.