VIKING UNST PROJECT: FIELD SEASON 2008 - Nabo

3.2.2 A geological assessment of the whetstones recovered from Hamar and theUpper House, Underhoull: the 2006 to 2008 assemblagesG. GauntIntroductionThis report includes the whetstones from both Hamar and Underhoull, recovered over thelast three seasons of excavation. Nine hones from Hamar and eleven from Underhoull wereexamined, principally to see how many (if any) were made from Eidsborg Schist and fromPurple Phyllite, the two lithologies that are believed to indicate “Viking” contact in theBritish Isles. Seven of the Hamar hones and nine of those from Underhoull proved to be ofEidsborg Schist, but neither site yielded any of Purple Phyllite. The main features of bothof these hone types are well known, so require no repetition here, but some additionalgeological aspects that may be of interest are included elsewhere (Gaunt 2000, 2484-2485,wherein the Eidsborg Schist hones are referred to as by their former name of NorwegianRagstone). To avoid needless repetition in the catalogues, the Eidsborg Schist hones areabbreviated to ES. Two hones from each site are made of other metamorphic rock types.Their lithologies are summarised in the catalogues, with suggestions on their possiblesources within the Shetland Islands. In the Catalogues each hone is identified by its smallfindnumber.Catalogue (Hamar)SF Context Area Commentsnumber173 139 A (Numerous pieces) ES261 214 C ES421 002 A Phyllite, medium grey, ‘slaty’ (i.e. on grain size boundarybetween slate and phyllite), with moderate slaty cleavage. NotPurple Phyllite (too fine grained). There are several phylliticsequences in the Shetlands, notably in the Clift Hills PhylliticGroup and the Dunrossness Phyllite on the mainland, butpossibly a more likely source for this hone is the Muness Phyllite,which has a local occurrence on Unst and also a superficial‘woody texture’ (Mykura 1976, 37).928 261 C Metaquartzite, pale grey, highly compacted, with moderatelydeveloped lineation texture. The nearest outcrop of ‘quartzite’ toHamar appears to be a ‘lenticular’ mass which forms the highestground on Yell (Mykura 1976, 33). Other quartzites are presentin Shetland however, most notably in the Scatsta QuartziticGroup (Mykura 1976, 24-25; for outcrop location see plate IV).1112 1019 C ES1162 369 A (Three fragments) ES1167 432 A (Three fragments) ES1168 1043 C ES1330 449 A (Three fragments) ESTable 3.1: Catalogue of whetstones recovered from Hamar35