Crop Marks

PhilB · **Posted:** Thu Oct 22, 2009 6:43 pm

I`ve been impressed by members` knowledge of crop marks and have been looking round fields on Google Map. This shot is of fields just to the east of Bradshaw Lane, Scronkey. As an idiot`s guide, could someone explain the various marks, especially what look like water course. Are these a remnant of the times when this was waterlogged?

wyrearchaeology · **Posted:** Thu Oct 22, 2009 7:08 pm

Phil,

The parallel lines running up and down the fields are modern coulter marks -- the coulter being the sticky-out bit at the bottom of a plough responsible for creating the furrow, as introduced to Blighty by the Romans if memory serves. These lines are closer together than mediaeval ridge and furrows, the diagonal parallel lines running across the fields in the aerial photograph more than likely fitting that particular period. (That was good grammar, wasn't it? I hope you can follow this, because I'm having difficulty now myself.)

The marks that scribble all over the place like the crinkles in a big green brain are old, mainly natural I suspect, water courses.

Here and there you can see straight-edged, long-since fallen-out-of-use, field boundaries (filled in ditches, uprooted hedgerows), the narrower fields more often than not being Saxon whilst later mediaeval fields tend towards being bigger and less regular in shape.

Some of them might be tracks...it's difficult to tell from aerial photographs.

There might even be something considerably more ancient amongst that lot, Bradshaw Lane having produced a number of neolithic finds over the years, although nothing immediately presents itself to the eye.

The black dot just below the farmhouse is possibly a cat or a very large rabbit.

PhilB · **Posted:** Fri Oct 23, 2009 8:55 am

Thanks, Brian. The crinkly marks look more like bogs than streams, perhaps? Presumably, the Fylde moss was a large bog at times. Why might only some fields show it while adjacent ones don`t? Presumably they couldn`t drain some fields while the next fields were boggy?

wyrearchaeology · **Posted:** Fri Oct 23, 2009 9:25 am

Phil,

The farmers'll no doubt know the answer to that one. I suspect it depends on what the fields were used for over the centuries. Deep ploughing and heavy marling and stuff is bound to have had more effect on rubbing out the crop marks than nibbling sheep would have had alone, especially if, as you say, said fields were drained whilst others weren't.

I suspect.

I honestly don't know. I'm just guessing here.

As for the 'bogs rather than streams' idea, those scribbly bits do have a certain look of creekiness about them. Satellite photos of Barnaby Sands look very similar, only still with the gullies intact, of course.

frankjsmith · **Posted:** Fri Oct 23, 2009 12:12 pm

Phil,
I find these satellite photos confusing in as much that if you compare google with multimap for instance, the same fields sometimes look totally different. This I would think is down to when the images were taken, winter or summer which would determine the type of vegetation etc.
Obviously the weather makes a great deal of difference to what can be seen, ie how wet or dry it’s been. (What I want is a 1976 summer!) The weather on the day can also make a big difference, especially for aerial photos, but it’s a lottery realy. I only fly in good weather, but it’s down to luck on the day, especially for ground contours, witness the photos of Bourne Hill last March, the sun was in exactly the right place to show all those features not previously seen. After talking to Mark at the meeting and seeing what he has found using special software on his computer, I had a go with auto corect on some of the many field shots I have, taken by my colleague Eric, who took the Bourne Hill photos. He knows what I’m looking for now and snaps away at things I don’t see.
There are three types of features I look for on the aerial photos, crop marks, soil marks and ground contours, and here’s an example I found of each:-

I don't know if there is anything of interest for you there, Brian, there's plenty more to have a look at, the hardest thing will be to identify the location of the fields, I know roughly what area they are in so I will have to search out the field shapes on a satellite photo.

PhilB · **Posted:** Fri Oct 23, 2009 7:52 pm

You`ll notice in the middle photo that the dark lines have been made serrated - obviously by a tractor crossing first one way, then the other. If that could happen with one tractor crossing, surely just a few decades would destroy them completely?
How do you interpret that picture (best guess)?

wyrearchaeology · **Posted:** Sat Oct 24, 2009 3:29 pm

Frank,

Let's see. Top photograph, old field boundaries (ditches) most likely. Could be Saxon, in which case there's probably a Tunstead, possibly even a Saxon hamlet at one end or the other of them. On the other hand they could just be Victorian field drains. The oval shapes, I suspect, are filled-in ponds. (I'm going to look a right Burk if they turn out to be roundhouses now.)

The second photograph might well be just natural drainage channels. Could be wrong, of course (always a good proviso to insert, I reckon), but I can't see much in the way of geometric shapes. Unless, of course, a larger pattern forms within the surrounding fields and we just can't see it.

Third photograph -- these sort of embankments and what have you always fascinate me. They're very rarely natural, especially when they appear to form a large square platform such as the one in the lower right hand corner. No idea whether they've been caused through modern or ancient work though. Further investigation required, perhaps -- such as asking Michelle to take a look, because she's much better at understanding this stuff than I am.

Phil,

Tractors can destroy a lot of archaeology and, unfortunately, frequently do, although it does depend on how close to the surface the archaeology is. As the ground builds up the archaeology becomes less likely to be damaged by a coulter and often, of course, ploughing follows the same ridge and furrows year after year, so the basic structure of anything underneath remains intact. It's a bit like dragging a fork over a piece of cheese, making sure that the prongs follow the same lines every time. The piece of cheese remains intact on the whole, albeit damaged where the prongs have ripped into it.

That simile's made me hungry now. Cathedral City on toast sounds good to me.

frankjsmith · **Posted:** Sat Oct 24, 2009 6:06 pm

I've managed to find the location of the fields in the photos:-

Top -POPLAR GROVE FARM Nateby
2nd -CALCALDS FARM Garstang Road Stakepool
3rd -HOOL FARM Kilcrash Lane Nateby

Phil,
You're right about the ploughing cutting into the diagonal feature, it makes me think it's fairly shallow, and as it starts at the gate from the farm it could be a path used to access other fields. The two lines parallel to the road could be hedge lines.
Brian,
Just goes to show we all see thins different, I hadn't noticed the square feature you pointed out, but I can see two possibly three smaller ones close to the farm.

wyrearchaeology · **Posted:** Sun Oct 25, 2009 8:10 am

Frank,

The smaller squares closer to the farmhouse look like depressions to me -- possibly ancient enclosures of some sort. I had a sneaking suspicion that the photograph might have been taken over Nateby. Knowing the significance of Hoole Farm, I suspect that all of the earthworks are prehistoric. I wouldn't mind sinking a trench or two into that lot.

PhilB · **Posted:** Sun Oct 25, 2009 9:44 am

What exactly is the significance of Hoole Farm?
In older times, were farmers in the habit of having a pond in most fields and digging one if necessary? That would mean that any circular crop mark up to 10m diameter, say, could now be assumed to be a filled in pond unless there were indications otherwise?

wyrearchaeology · **Posted:** Sun Oct 25, 2009 4:32 pm

Phil,

Hoole Lane in Nateby is at the centre of a massive array of prehistoric earthworks, ranging from the Bronze Age to Romano British. Hoole Lodge, for example, (at least, I think it's called Hoole Lodge -- it's the place at the junction of Longmoor Lane and Hoole Lane whatever the case) is sat in the middle of an enormous henge (one of at least three running towards Garstang), which, in itself, is bisected by a Romano/British road. You can't move around the Hoole Lane area without tripping over something ancient.

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Crop Marks

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