66 The Ottawa Naturalist [Aug.-Sept. 



result in a basal conglomerate resting with unconformity on 

 older strata, and succeeded by sandstone and limestone in which 

 occur Maclurea magna. 



Long after the deposition and lithification of the formation 

 described, and perhaps of several succeeding ones, tectonic 

 forces cause the deformation of the sub-zone X in the zone E. 

 Obviously the age of the phenoclasts in this tectibreccia is much 

 younger than the ages of any of the phenoclasts heretofore dis- 

 cussed, whether they are intraformational or even interform- 

 ational. Finally, it is a fact that not all the types described 

 can be distinguished in the field at a glance. Type X may be 

 easily confused with gliding deformation structures; type D with 

 type F, etc. 



BIBLIOGRAPHY. 



1. Wal:o';t, C. D.,: "Paleozoic Intraformational Con- 

 glomerates." Bull. Geol. Soc. Am., 1894, 5, p. 191. 



2. Grabau, A. W. : "Principles of Stratigrapy," N.Y., 1913. 



3. Hahn, F.F.: " Untermeerische Gleitung bei Trenton 

 Falls (Nord Amerika) und ihr Verhaltniss zu Ahalichen Storungs- 

 bildern. Neues Jahrbuch fur Mineralogie, etc. Beilage Band 

 XXXVI, pp. 1-41, taf. 1-3, 1912. 



4. Miller, W. J.: "Notes on the Intraformational Con- 

 torted Strata at Trenton Falls." Report of the Director of the 

 N.Y. State Museum for 1914, 1915. 



5. Kindle, E. M.: "Columnar Structure in Limestone." 

 Museum Bull. 2, Canada Dept. Mines Geol. Sur. 14, 1914. 



6. Hyde, J. E.: ' Dessication Conglomerates in the Coal 

 Measures Limestone of Ohio." Am. Jour. Sci. XXV, 1908, p. 400. 



7. Seeley, H. M.: Report of the Vermont State Geologist 

 for 1906, pp. 174-178. 



8. Brown, T. C. : "Notes on the Origin of Certain Pale- 

 ozoic Sediments. Illustrated by the Cambrian and Ordovician 

 Rocks of Centre County, Penna." J*ur. Geol. XXI, 3. 



9. Seeley, H. M.: Report of the Vermont State Geologist 

 for 1901-1902, p. 153. 



10. Sardeson, F. W. : "Characteristics of a Corrosional 

 Conglomerate." Bull. Geol. Soc. Am, 25, 1914, p. 271. 



11. Wallace, R. C. : " Pseudo-brecciation in Ordovician 

 Limestone in Manitoba. 



12. Walcott, C. D.:"The Cambrian Rocks of Penna." 

 Bull. 134, U.S.G.S., 1896. 



13. Agassiz, A.: "Three Cruises of the .... Blake," vol. 1, 

 p. 87, 1888. 



14. Raymond, P. E. : Excursions of the 12th International 

 Congress, 1913. Guide Book 1. Excursion A 1, part 1, p. 29. 



15. Sardeson, F. W. : "The Folding of Subjacent Strata by 

 Glacial Action." Jour. Geol. XIV. (p. 226), April-May, 1906. 



