Cenozoic Formations Research Articles

Comparison of American and European lower Ordovicic formations

Introduction Geologists familiar with the formations of both hemispheres will in general agree that while Europe must always serve as the type region for the Mesozoic and Cenozoic formations, the North American Paleozoic should be considered the standard by which other deposits of that age must be judged. In no other known region is there such an extensive development of the older formations, both in their marine and continental phases, and in no other known portion of the world is the record so clearly preserved as in the Paleozoic rocks of the greater part of the North American continent. This is especially true of the earlier systems, which have not only a slight representation over much of Europe, but are for the most part strongly disturbed; or, where not so affected, as in the Russian region, are in large part covered by comparatively recent surface deposits. This is emphasized by . . .

Concretions and their geological effects

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

Mesozoic and Cenozoic Formations of Eastern Virginia and Maryland

Introductory. The crystalline rocks of the Piedmont region in Virginia and Maryland are flanked eastward by an overlapping series of deposits of later Mesozoic and Cenozoic age, which extend thence to the Atlantic ocean, a distance averaging one hundred miles. This district has been designated the “coastal plain,” and is in general terms the continuation of the Piedmont plains which, with gradually decreasing elevation, finally pass beneath sea-level. The eastward inclination of the crystalline rock-surface on which the coastal plain deposits lie is slight, and the width of the zone of overlap from the feather edges and outliers of the formations to the final disappearance of this floor below tide-level usually averages about ten miles. The irregular western terminations of the various formations usually do not give rise to notable topographic features, and in the larger drainage depressions the crystalline rocks finally disappear below the clastics, generally at a Considerable . . .