Sentence:  The Champlain clays are believed to have a somewhat special arrangement of the individual soil particles such that the plate-like particles are oriented to each other in an edge to face arrangement in the undisturbed condition, i.e. "<WSD>cardhouse</WSD>" structure. 
Meaning of the word marked with <WSD> tags:  A structure of plate-like mineral deposits that rest on each other's edges, similar to a cardhouse.