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I recently heard of a couple of pipelines in the Southeast of England where there wasn't a watching brief on all the route. I would have presumed that this was standard on all pipelines. Does anyone know otherwise?
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I have no idea which piplines these were and have had no involvement in them, however there are times when you wouldn't have a watching brief on a whole route. For example, if the route is going through an area where the remains would have previously been removed (e.g. quarries) or if they are following the line of an existing spread where there had previously been a watching brief.
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Not sure of the details but as I understand it, someone is so confident with all the archaeology that was revealed through the geophysics results and subsequently targetted and excavated, that there is no need for a further site presence. Seems to me that this strategy would miss the likes of smaller pits and pit constructions, isolated features, unstrat finds, for example. Not to mention that this would exclude the recording of historial field boundaries and their origins which suggests that no atention is being paid to landscape development.
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Without casting too many aspersions on the efficacy of geophysics, I reckon event the most optimistic geophysicist would admit that no geophysical technique or combination thereof will identify 100 per cent of the archaeology
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Erm.. not sure where the presumption of a watching brief on all pipelines comes from. Perhaps you could direct me to the document endorsing this policy. In my view archaeological works on development should be justifiable and timely - applying blanket watching briefs on schemes doesn't seem to fit these criteria. The geophysics aside - no evaluative technique will 'identify 100 percent of the archaeology'. I think the key statement here is 'Not sure of the details'.
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I agree! Any mitigation strategy shuld be appropriate to the project.
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As a geophysicist I can confirm that there is no way that geophysical surveys can be expected to provide a complete picture of the archaeology of pipeline corridors. I have been involved in two such surveys of late, and whilst both proved valuable in detecting archaeology, neither was entirely effective and in neither case do I believe that the 'blank' areas will necessarily prove to be blank.
Apart from the usual caveats with geophysics (it doesn't work well on all geologies, can't 'see' much below alluvium, colluvium or made ground and struggles to detect post-holes, burials etc), there is a particular difficulty with linear projects. Interpretation is usually based on the plan view of sites and thus it becomes much more difficult when only a narrow (c20-40m) strip of data is available.
Another problem with pipeline corridors is that they often follow the route of previous pipes, and so there will be streches of the data where any archaeological anomalies which may occur are swamped by the massive magnetic halos from these pre-existing pipes.
Apart from the above considerations, it would be unsual for a geophysical survey to cover the entirity of a pipeline route. Woodland, waist high rape crops, over attentive livestock, shotgun waving gamekeepers and so forth have a habit of getting in the way. It also seems par for the course that the route you're sent to survey will differ in stretches from the one which the pipeline actually ends up following.
I'm not saying that geophysics on pipeline corridors is a waste of time. It can, and does, provide valuable results. Its just that one should be very wary of placing too much weight on survey results alone.
John
"Hidden wisdom and buried treasure, what use is there in either?" (Ecclesiasticus ch20 v30)
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Vulpes,
'Not sure of the details' doesn't justify why a presumption that all the archaeology on a pipeline has been located and resolved.
There is no policy of a watching brief on all pipeline activities but commonly there is. Justifiable and timely can only amount to one decent archaeologist with eyes in their head. It isn't a great expense on the grand scale of pipelines and will surely contribute to adding more information to the SMR.
Watching briefs on trenching is a very good check to the effectiveness of the geophysics, eval and excavations, and lessons can be learned for future projects.
I know of a great deal of archaeology located in trenches, sometimes whole sites which were simply not detected by geophysics or seen during during topsoil stripping because they were too difficult to see either because they were hidden within the sub-soil or because not enough topsoil was removed by the main contractor.
Another common mistake is the assumption that because there are no records of archaeology in the area that only a watching brief on the topsoil stripping will suffice; this is probably the worst strategy in that there are perfectly decent reasons why archaeology has not been found such as its under coluvium, soliflux, the area has been subsoiled, archaeology has been ploughed-out, covered by flooding episodes or even still being utilised today, such as field boundaries, trackways, roads, for example. Not locating features such as these denies an understanding of the archaeoloigcal process as well as the archaeology.
In my experience, its generally there but you have to look to find it rather than not looking at all.
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Nicely said Sparky,i've allways found the best approach to archaeological investigation is:clean the site (where possible),record in plan and then draw up your strategy of what needs to be dug and THEN interpret the site.
But hey, its amazing how much archaeology never existed when you don't look in the first place!!:face-confused:
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Noted, thanks for the advice. Close and continuous watching briefs on everything from now on, and I'll also make sure that all spoil and topsoil is sieved for 100% finds recovery. Forget the cost this is our heritage what's at stake. Oh, I forgot to mention daily monitoring visits to make sure these instructions are being carried out to the letter. As an archaeologist I can confirm that no evaluative technique will give a complete picture of anything. Never heard of sampling...? Lycka til