Edit a page: Rapid Member

For Help in formatting please see the Wiki Help

Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p. ==Contributing author(s)== Charles Collinson and Elwood Atherton ==Name== ===Original description=== The Rapid Member of the Cedar Valley Limestone (Keyes, 1912, p. 149; 1913, p. 205-206). ===Derivation=== Named for a locality in Johnson County, Iowa, not specified by Keyes. ===Other names=== ===History/background=== ==Type section== ===Type location=== ===Type author(s)=== ===Type status=== ==Reference section== ===Reference location=== ===Reference author(s)=== ===Reference status=== ==Stratigraphic relationships== The Rapid Member of the Cedar Valley Limestone overlies the Solon Member. ==Extent and thickness== The Rapid is the most widespread and thickest member. It is as much as 60 feet thick in the Rock Island area, but it thins to the east and south. It forms the upper 53 feet of the quarry southeast of Milan. ==Lithology== The Rapid Member consists of gray to buff, fine-grained, argillaceous, locally dolomitic limestone. Most of it is thick bedded, but the upper and lower parts are thin bedded and have shaly partings. ==Core(s)== ==Photograph(s)== ==Contacts== ==Well log characteristics== ==Fossils== Some beds, especially near the top and bottom, are very fossiliferous. Brachiopods and corals are most common, particularly ''Atrypa'', ''Stropheodonta'', ''Chonetes'', ''Spirifer'', ''Schizophoria'', ''Pentamerella'', ''Hexagonaria'', ''Favosites'', and ''Heliophyllum'' (Edmund and Anderson, 1967) (fig. D-6). Conodonts indicate a late Middle Devonian age (Collinson et al., 1967b). <center> <gallery caption="" widths=250px heights=250px perrow=4> Figure D-6.jpg|alt=Photograph or illustration showing fossil assemblage of the Rapid Member including brachiopods and corals such as Atrypa, Favosites, and Heliophyllum (Figure D-6)|{{file:Figure D-6.jpg}} </gallery> </center> ==Age and correlation== ==Environments of deposition== ==Economic importance== ==Remarks== ==References== COLLINSON, CHARLES, M. P. CARLSON, F. H. DORHEIM, and J. W. KOENIG, 1967b, Central Iowa Basin, ''in'' International symposium on the Devonian System: Alberta Society of Petroleum Geologists, v. 1, p. 963-971; Illinois State Geological Survey Reprint 1968-G.<br> EDMUND, R. W., and R. C. ANDERSON, 1967, Mississippi River Arch: 31st Annual Tri-State Field Conference Guidebook, Augustana College, Rock Island, Illinois, 64 p.<br> KEYES, C. R., 1912, Some provincial and local phases of the general geologic section of Iowa: Iowa Academy of Science Proceedings, v. 19, p. 147-151.<br> KEYES, C. R., 1913, Late Devonic sequence of the Iowa region (synopsis): Iowa Academy of Science Proceedings, v. 20, p. 205-206. {{Codes |membercode=5950 |geo_unit=-- }}

place a <pre><br></pre>at the end of a line to get a line return

Save page Show preview Show changes Cancel