Introduction Some over thirty years ago the writer’s attention was turned to the peculiar cracked concretions abounding in loess, which are known as loess kindchen. Not satisfied with current explanations of their origin and history, he has ever since improved opportunities to note and collect concretions, which abound in vast numbers and of numerous types in the Mesozoic and Cenozoic formations of the west. This paper presents some of the more prominent conclusions for consideration and criticism. Some well known facts are briefly recapitulated for the proper setting forth of the more novel conclusions. It should be stated at the outset that the author disclaims intimate acquaintance with the chemical aspects of the subject. His data are mainly observational, not experimental, and his discussion physical and not to any considerable degree chemical. Literature on the subject is meager. Some writers comment on the subject as quite obscure.[*][1] Concretions Defined Concretions . . . [1]: #fn-1