Dear Mateusz,

it will be nice to "clean" the outcrop to better see deformation and their rooting in the downer part.

However, the deformations are convolutes bedding;  many possibilities: post sedimentary cryoturbation or fluidification of the sediment due to moving water  by seismic events or slumping...

Best regards

Mateusz:

You need to prepare a high resolution litholog to understand the folding and possibly microfaults caused due to fluid and overburden. Kindly see this link for insights:

https://atrium.lib.uoguelph.ca/xmlui/bitstream/handle/10214/9361/Arnaud_2011_ThePaleoclimaticSignificance.pdf?sequence=3

Best

Syed

Dear Mateusz,

I agree with Jerome's interpretation (and with the need for profile cleaning:); this looks like 'typical' convolute bedding.

Sedimentary Geology has recently published a special issue on soft sediment deformation (http://www.sciencedirect.com/science/journal/00370738/344), where you can find case-studies and bibliographic references.

Best,

Diego

I saw something similar in the Weyburn area, Southern Saskatchewan, Canada.

You can consider the possibility that the deformation is caused by the advance of a large front of thick ice over a hard substratum, "soon" after the deposition of a few meters of glacio-lacustrine deposit in a lake formed at the front of a large ice cap.

The immense force of the advancing ice front would bulldozer the lacustrine sediments sideway, deforming them in the way you documented.

The deformation of the deposits when they were still not litified (fresh sediment) would justify the apparent lack of proper faults.

Dear Mr. Pitura,

it is a common problem in sedimentology. You have an image taken at outcrop and you neither know what the lateral facies change looks like nor the vertical one. Convolute bedding like that could have orginated from a wide range of processes. One of the "closest" assumption is that of forming part of  a "push moraine" when ice was on the move. You may find nice images of this kind of soft sediment alteration across the periglacial region in Europe, e.g., Moler Fm. Denmark. It can be caused by seismic activity, even if Central Europe is not an earthquake prone region. Soft sediment deformation like that may also caused by diagenetic processes related to dewatering. Tectonic processes are still active in many basins in Europe. As I have no personal insight into the Polish Quaternary Geology, I can only offer you some possibilities to account for these structures. How to fit them into the lateral and vertical facies changes will by a task of yours.

I wish you much success

H.G.Dill

Dear Mateusz

The deformation of glacilacustrine sediments could be due to many processes, both syn- and post-depositional (fluidisation, density-driven deformation, glacier overriding; etc.). Looking at the photographs, I do not see any clinching evidence for glacitectonics (but this does not mean that this can be excluded, as the strain signature may vary both vertically and laterally, as someone else pointed out).

In some ways this reminds me of work that we did in Waterville, Ireland (Evans et al., JOURNAL OF QUATERNARY SCIENCE (2012) 27(1) 51–63).

Dear Mateusz,

The structures you shown could be created by a variety of processes (as suggested by others who have responded to your question). The fact that the structures are created in glacio-lacustrine deposits suggests that ice may have had a role to play. I attach a paper that deals with structural details of ice-related deformation of underlying sediments.

Thanks

Ian Alsop 

Article Incremental subglacial meltwater sediment deposition and def...

I think Prof. Dill and Prof Aslop have covered the key issues.

The features are unquestionably soft-sediment deformation (SSD) features (given your observation that there are no faults in the vicinity). Several publications (including a recent special issue of Sedimentary Geology) focus on that topic. Recommend it strongly.

Also suggest special caution in differentiating the dewatering / soaking (thixiotropic) - deformations that essentially operate under the influence of gravity (in response to the pore-fluid stresses) and seismites. Not all SSD's are seismites. Temptation to link to seismic events / tectonism is great in most such deformations, but one needs to remember that such soft sediment deformation is common in deposits formed in rapidly fluctuating environments.

All the best.