The topic has been discussed (in relation to the UK) in a recent Nature Article by Matt Ford (Download a pdf here). Many of the issues raised ring true in Ireland as well and probably most countries where archaeology has become an integral part of the planning and development process. Since the early nineties in Ireland there has been a requirement to totally excavate archaeological sites prior to development. This led to the creation, exponential expansion and subsequent implosion of an Irish commercial sector.
This sector has created a huge amount of data in various form: feature and context sheets in the worst cases and completed final excavation reports with specialist analysis in the best. So is it a hidden treasure? I think it definitely is, if a little too well hidden! My PhD research is based on a database of excavations with evidence of iron smelting or working and the vast majority of these have been excavated commercially in the last twenty years. This type of synthesising PhD is becoming very common in Ireland and in combination with the INSTAR projects (listed here) promise to transform our understanding of the Irish past.
However, the picture isn't entirely golden. The quality of reports is often good but in many many cases final reports just don't exist: they haven't been completed years after excavation has finished. This kind of thing is exasperated by archaeologists moving on from companies and even from the profession. Standards are not enforced and while I have a generally good impression from many of the reports I've sifted through, these are likely to be the best of the best because they have come from people or companies willing to share. Its the reports I can't get my hands on that I worry about. I think in the next few years the biggest worry will be non-existent or 'Ghost' literature rather than the much more viable and useful Grey Literature.
This is part 1 of a series of 3 posts on Grey Literature and Archaeology.