Besom Hill, Manchester, UK Carboniferous fossil hunting

[avimatorz]

I had recently made a visit to Besom Hill, Old Ham, Manchester, UK for the spectacular remains of carboniferous fossils such as calamities, gastrioceras, and many more. Although I found some strange impressions in the shales (Listeri Marine band) and wished to get some idea on what it might be. It appears as an impression on the dark shale, has a sort of 3D impression on bottom and top. The pattern is lines radiating in a parallel manner, with slight but observable curvature. Surface is not flat, rather slightly wavy. First impression was possibly burrows, but probably not. Would it be some sort of shell or plant impression instead? Another specimen follows along as a cylinder.

[TqB]

Welcome to the forum! 
I think these may be sedimentary structures, caused by softer shale sliding over harder objects (e.g. shells or concretions) or along joints as it's compressed to produce a striated, polished interface. Effectively a mini-slickenside.
I see a lot of it in nodular marine shale beds in the lower Carboniferous in my area (Co. Durham). 

Edited April 13 by TqB

[Rockwood]

The bottom photo looks a lot like Artisia. A pith cast from a Cordiates trunk. I think this could be coalified wood from the same. 

[TqB]

As Rockwood says, carbonized plant material is a possibility as well as mini-slickenside. To me, the second photo looks more like thin, coalified wood but it's hard to tell as the others don't.  (I don't think the second is Artisia though…)

[avimatorz]

Thank you very much, those interpretations are definelty useful!