mirror on greenland archaeologists uncover clues to why vikings abandoned greenland spiegel online refers to an interesting study with detail including dates which would be useful here the study itself seems to be norse greenland dietary economy ca ad ca ad introduction jette arneborg niels lynnerup jan heinemeier jeppe m hl niels rud and rn e sveinbj rnsd ttir journal of the north atlantic vol special volume greenland isotope project diet in norse greenland ad ad pg s possibly worthwhile but paywalled talk