Clogwynygarreg
Also within
Geology & landscape
Landscape processes: Glacial, Periglacial
Description
Description Clogwyngarreg is an important palynological site recording detailed evidence for Late-glacial and Post-glacial vegetation and environmental changes in North Wales. It is one of the very few sites in Wales where a detailed Late-glacial pollen sequence has been calibrated with a 14 C timescale. Organic sedimentation began after about 13,670 BP, a date which provides a minimum age for Late-glacial Interstadial, while a later decline particularly in Juniperus pollen marks deteriorating conditions culminating in the Loch Lomond Stadial. During this period (c. 11,000-10,000 BP) small glaciers reoccupied corries in the Snowdon massif, and Clogwyngarreg lay in the periglacial zone. A change from minerogenic to organic sedimentation and the rapid ecpansion of Juniperus pollen marks the transition from the cold stadial period to milder environmental conditions in the Early Flandrian. Clogwyngarreg provides a contrasting record to that of nearby upland sites at Llyn Idwal and Cwm Cywion and helps to place further constraints on the age of the final corrie glaciation of North Wales.