A Holocene pollen profile (GLU IV) from Glenulra, Céide Fields, Co. Mayo, Ireland

The sampling site was in a small basin-bog (ca. 300 x 100 m). The basin is surrounded by blanket bog that has preserved a pre-peat, extensive stone-wall, regular field system, referred to as Céide Fields. The research project, part-funded by The Heritage Council (of Ireland), commenced in 1992. The aim was to provide an environmental context for the establishment and use of the prehistoric stone wall field system and also to provide an overall chronological and palaeo-environmental framework. After establishing the basin contours and the general stratigraphy of the basin using a gouge corer and also taking trial cores for preliminary pollen analysis, the peat core GLU IV (∼5.8 m long; 10 cm diameter) was taken using a Wavin plastic pipe. The pollen and macrofossil investigations were carried out by Karen Molloy. In all, 77 samples were analysed from 150–574 cm (depths with respect to the bog surface). The pollen profile spans >6800 BC–AD 700, i.e. Boreal to early Medieval period. LOI and tephra investigations were also carried out. A substantial tephra layer was recorded at 228–232 cm (ca. 600 BC according to the age-depth model). The results of the tephra investigations have yet to be published. Twenty two conventional 14C dates (Groningen 14C laboratory) were obtained. Twenty of these 14C dates were used to establish the age/depth model that is derived from a fifth order polynomial regression curve obtained using Clam v. 2.2 (details are provided). This is the age/depth model used in the EGQSJ publication (in press, 2019).