poches et lentilles

18:24 Dec 9, 2018 

I tend to say "pants" to MT post editing.

17:28 Dec 9, 2018 

It does appear that "pockets and lenses" is a genune geological term, quite well represented on Google. Initially I had rejected this because the job I was given was to correct a machine translation which, of course, gave excactly that, "pockets and lenses" so I didn't even bother googling it, this being the same text where "culotte" was given as "panties" by Google... ("Chaque pied de chute sera équipé de culotte et coudes au 1/8e avec tampon de visite."). But Marco has, I think, set me right.

17:07 Dec 9, 2018 

It's not about size. Only compressible materials that exhibit flow will form lenses when subjected to pressure. Compressible materials may be found in pockets either because they weren't subjected to pressure or because they don't flow.

15:42 Dec 9, 2018 

Reading your blurb, it seems that the distinction may just be one of size. Both seem to be quasi-hemispherical depressions or cavities of some sort, especially given that excessive compressibility is the issue. Or could the "lens" be a negative depression, i.e a rock or pebble ?? Helpfully (?), my dico des sciences de la terre suggests "lentil" for "lentille rocheuse"...

13:19 Dec 9, 2018 

I'm not sure about this but "lentilles" could be this
https://en.wikipedia.org/wiki/Lenticular_bedding
Poches is probably pockets.