. Bulletins of American paleontology. i» ' cross-slrati'ied ' laminar stromaloporoids Text-figure 14.—Two stratigraphic sections of tfie Nora Member are shown; the upper secton illustrates stratigraphic changes as one traverses away (east) from the more massive calcareous facies of the Nora, as would be seen in the subsurface shortly to the west of the outcrop belt. The lower section illustrates similar facies changes from Portland to Rockford, with a similar more distinct development of the two biostromes of the Nora Member in the eastern area (Localities are shown on Text-figures 3,11).. Exp
. Bulletins of American paleontology. i» ' cross-slrati'ied ' laminar stromaloporoids Text-figure 14.—Two stratigraphic sections of tfie Nora Member are shown; the upper secton illustrates stratigraphic changes as one traverses away (east) from the more massive calcareous facies of the Nora, as would be seen in the subsurface shortly to the west of the outcrop belt. The lower section illustrates similar facies changes from Portland to Rockford, with a similar more distinct development of the two biostromes of the Nora Member in the eastern area (Localities are shown on Text-figures 3,11).. Exposure - Shell Rock Fm. Rudtd 7 1/2 Min. Quad. Text-figure 15.—Location of exposure of Nora Member at Rudd, Iowa. Further details are in the Appendix. stromatoporoids and at several levels is biostromal in aspect (Text-fig. 24). This is the source of much of the coral fauna of the lower part of the Owen Member The upper portion of this middle unit is generally speaking, dolomitic and argillaceous. The unit is soft, and weathers into slopes between the carbonate units below and above. It is characterized by gastropod and pelecypod faunas and characteristic spiriferid and cho- netid brachiopods. Its soft, dolomitic nature makes it an easily recognizable unit where it is exposed. Upper beds ("Acerviilaria zone" of Fenton, 1919, p. 366) This thin unit of light gray-weathering micrites is easily recognized and bears the most abundant coral faunas of the Owen Member. An average thickness approximates that seen in western Owen Grove, where well-exposed beds are m. The unit is never thick, but has been the source of most of the coral species described from the Owen Member. The single expo- sure that contributed most specimens is the now-aban-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Paleont
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