I would like to know what "snow in the crevices of a boggy bank" means in the following sentences:
Her cheek near his sleeve, she studied a dozen village pictures. They were streaky; she saw only trees, shrubbery, a porch indistinct in leafy shadows. But she exclaimed over the lakes: dark water reflecting wooded bluffs, a flight of ducks, a fisherman in shirt sleeves and a wide straw hat, holding up a string of croppies. One winter picture of the edge of Plover Lake had the air of an etching: lustrous slide of ice, snow in the crevices of a boggy bank, the mound of a muskrat house, reeds in thin black lines, arches of frosty grasses.
Carol, a librarian at St. Paul Library, and Kennicott, a doctor in a small town called Gopher Prairie, went tramping together. After a walk, sitting on a bank, Kenicott persistently persuaded her to marry him and settle down in Gopher Prairie, saying that it was the nicest town in the world. He even brought some pictures of the town to show her.
In this part, I could not understand what were the "crevices" of a "boggy bank." Does "boggy" mean that the bank resembled a bog? And how can there be crevices in the bank...?
I would very much appreciate your help. :)