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Here are two images of English hill figures (The Cerne Abbas giant and the Uffington white horse):

cerne abbas giantuffington white horse

These hillsides, which are obviously grazed by sheep, show tracks that form numerous contour lines around the said hillsides. According to many people, however (e.g., Wikipedia), these contour lines are not generated by domestic livestock.

If that is the case, what causes these lines and why do they only appear on hills that are grazed by livestock? If, on the other hand, no livestock grazes these pastures, what keeps the grass so short and why are English farmers wasting such huge amounts of good grazing land? Are they mad? Some people, such as this answer, say the lines are caused by natural earth movements, but won't explain why they only occur on hills that are grazed by livestock. There are many more examples, and better ones, of chalk hill contour lines available on Wikipedia, but my simple explanation of how to find them has been deleted. The Long Man of Wilmington is a much better example than the two photos above, it shows the sheep as well as contour lines and is available on Wikipedia.

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    $\begingroup$ Could you add an image to your question or at least link to a page? Hard to tell what you mean exactly... $\endgroup$ – Spacedman Oct 12 at 13:06
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    $\begingroup$ its better that you do that and include it in your question than each of us looking at your question has to go and do that ourselves, getting different results, and possibly misinterpreting your question. Make it easy for us to help you. You are much more likely to get answers if you do. Edit your Q, click the little image in the editing tools, and follow the instructions. If you still can't do that you can ask for help on the "Meta" site (link from menu in top right). $\endgroup$ – Spacedman Oct 12 at 13:43
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    $\begingroup$ That's not the right way to do questions here. Make the question as self-contained as possible. Include images in your Q. I've looked at lots of chalk figure pictures (and have visited a few) and I still don't understand what contour lines or markings you are asking about. Ideally you could edit an image and add annotations pointing at the lines. The first bing image hit for me is this: upload.wikimedia.org/wikipedia/commons/0/02/… what lines are you on about? $\endgroup$ – Spacedman Oct 13 at 10:46
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    $\begingroup$ The contour lines which I say are made by animals and others say are "natural earth movements". Some examples I have seen follow the contours so exactly they look like the contour lines on a map. The Wikipedia examples are not the best ones, but they're good enough. If there is a button I could click to transfer them to this page, I'd click it, but if there is such a button, I don't know where it is. They didn't teach me about computers at school. Nevertheless, I can apparently do things with my computer which some people find difficult. $\endgroup$ – Michael Walsby Oct 13 at 11:08
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    $\begingroup$ I've now added the first two images into your question, they'll show up when a moderator approves. I've also added two queries where you should say who these "some people" are who say various things about the lines, since then we can investigate their theories - do they have a scientific backing or is this just pub chat? Where's the scientific argument? $\endgroup$ – Spacedman Oct 13 at 11:20
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Those lines have nothing to do with animals.

Those lines are generated by solifluction and frost heave. It is sometimes referred to as cryoplanation or soil creep. Basically as the thin hillside soil freezes and thaws it expands and contracts and because there is a slop it moves downslope. In addition rain combined with how the surface thaws before the deeped ground causes a plane of weakness and movement. It can form a variety of patterns but on strong slopes it tends to form stripes or ripples.

That area of England is well known for such landform. Below is a picture from Dorset and another from the isle of wight. They don't only occur on grazed ground, but if ground has trees they act as anchors for the soil and you don't get the more noticeable lines and nobody is going to graze animals on ground with nothing but trees or hills with no soil which also will not have them.

enter image description here

enter image description here

1. Sugden, David E. (1971). "The significance of periglacial activity on some Scottish mountains"

2. frost creep and gelifluction features a review

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  • $\begingroup$ This question appears to be a continuation of the "debate" over at earthscience.stackexchange.com/questions/18185/…. Your explanation makes sense, but given the controversy over on the other question, I wonder whether you can add any sources? $\endgroup$ – Semidiurnal Simon Oct 13 at 17:30
  • $\begingroup$ @SemidiurnalSimon I added a few more. $\endgroup$ – John Oct 13 at 17:38
  • $\begingroup$ +1 for including links for further reading! $\endgroup$ – samcarter Oct 13 at 17:43
  • $\begingroup$ @john thanks! 123 $\endgroup$ – Semidiurnal Simon Oct 13 at 19:38
  • $\begingroup$ So livestock grazes steep hills without contouring or leaving any tracks. Amazing! I bet David Attenborough didn't know that. It would be well worth his while to find out how they do it. I must confess though, that I have seen similar marks to these left by receding shore lines if ancient lakes. The ridges in this photo seem too regular to have been made by animals. $\endgroup$ – Michael Walsby Oct 13 at 19:59

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