11:36 Jan 27 

which in some contexts is taking material from its natural place and replacing it for use in another. But that doesn't really fit this context does it? I think that you may need to ask the authors, unless this document is about artificial sandy beaches.

11:12 Jan 27 

Hi there,
If I understand it correctly, these are areas of land where instead of rock or otherwise "solid" material there is granular material (clay, gravel, silt), a "pocket" so to speak

17:47 Jan 26 

Tu dice, "mi è chiaro di cosa si tratti" invece a me no. Potresti elucidare? The only meaning I can attribute is that of granular material for extraction, which doesn't make much sense in the context of a discussion of geophysical survey methods.