Editing Fanad (section)

==Geology and geography==
Geological maps of [[County Donegal]] show rock alignments running south-west to north east across the Fanad peninsula. The underlying rock in the peninsula is mostly of [[Dalradian]] meta-sedimentary rocks, which have been exposed by weathering and erosion over the millennia There are areas of [[Granodiorite]] igneous rocks across the northern end of the peninsula from Ballywhoriskey to Fanad Head, but the greater part of Fanad consist of Middle-Dalradian Quartzite and some Pellite rocks with local occurrences of [[Schists]] and Tillites – the latter mostly concentrated around the northern inlet of [[Mulroy Bay]].<ref name="auto3">As per maps and text of Chapter One  – Geology and Geomorphology by Moore, Cooper, Dunlop and Jackson, from Lough Swilly – A Living Landscape, Ed. Andrew Cooper (2011)</ref>

The cliffs around Fanad Head are of exposed Grandiorite, whereas the higher ground running south from Fanad Head to [[Portsalon]] is a band of [[Quartzite]].  Knockalla Mountain is also formed of Quartzite.

The landscape of Fanad has been shaped by geological processes which include the effects of periodic covering with ice sheets and glaciers as recently as 14,000 years ago. The retreat of the ice sheet had a major impact on Fanad and surrounding areas. It is speculated that much of Lough Swilly was may have been dry land which was flooded due to a rise in sea level within the last 10,000 years. Mulroy Bay may have been similarly formed at this time. The peat outcrops on the foreshore at White Strand north of [[Rathmullan]] contain the remainder of trees which were submerged by the advance of the sea in this area.<ref name="auto3"/> Many of the beaches on the Fanad shoreline were formed at this time by glacial deposits which were subsequently reworked by the actions of waves and currents.

In common with much of the rest of Ireland, the post-glacial landscape gradually changed with rises in temperature from open tundra to one dominated by forests of pine, oak, alder, hazel and birch, with breaks in the canopy on the edges of the intervening expanses of lake and bog. This was probably the landscape which greeted the earliest settlers who ventured along the coastline in the late Mesolithic Period, possibly about 5,000 BC. There is archaeological evidence of human occupation of coastal areas of Inishowen at Dunaff<ref>Ref. Chapter 1 – Prehistoric and Early Historic Settlement in Donegal by Brian Lacy from Donegal History and Society – Ed. Nolan, Ronayne & Dunlevy (1995)</ref> and west of Horn Head during this period and it is reasonable to assume that Fanad also saw some transient occupation at this time.

The subsequent evolution of the landscape in Fanad probably owes more to human intervention than to natural forces, reflecting the shift from visits by [[Mesolithic]] hunters, fishers and gatherers to the introduction of primitive farming during the Neolithic period from 4,000 BC onwards. The tree-covered landscape of the Mesolithic period would have given way gradually to a more open countryside in arable areas, marking the beginning of the contemporary landscape of Fanad, with its mixture of arable land at lower levels, with scrub and gorse covered uplands, and bogs interspersed with occasional lakes and streams.