good or bad sign?

[mandypoo]

We've been digging a rather small phreatic tube filled with mud/silt. There is airspace over the top, and now we've got to a situation where the sediment gets really unusually quite "wave-like"! Any idea what this could be a sign off? Hopefully not a massive blockage filled to the roof further on!

 

[martinm]

any draught?

 

[mandypoo]

hard to tell very weak if any, start of it quiet wet, so its cold and unpleasant! No sign of bad air though

 

[bograt]

"Wave like " could indicate scalloping, a good sign, a picture could give us some guidance.

 

[Aubrey]

'Wave' type ridges can be formed as water recedes on and through a sandy base.

I am not sure it means anything specific in digging terms other than you have not broken through yet!
Keep at it. 

 

[cavermark]

Do you mean ripple marks in the surface of the sediment, or curved layers in the sediment?

Ripple marks would suggest some water flow when (or after) the top layer was deposited so that might mean an airspace continues..........

 

[mandypoo]

Cheers for the responses.
Cavermark, the whole layer of sediment which when we started digging was fairly level has become quite wavy, as aposed to just small ripples on the surface.

I guess we'll just have to persevere and and see what happens!

 

[gus horsley]

Maybe the wavy effect is due to an increase in the draught (but I'm not sure why that would be) which creates larger water ripples.  I've dug similar features in the past and found the sand/mud has slumped back in but usually there's been a relatively flat surface.  Draught or not, it's still worth pursuing if it's diggable.