4 W. H. Tivenhofel — Physiography of 3 eiofoundland. 



igneous rocks, probably intrusive in the sediments. Where 

 these terminate, the limestones, shales, and conglomerates of 

 the north reappear, repeating the sequence but in a reverse 

 direction. From St. George Bay to the southwest corner of the 

 island the rocks are of Carboniferous age, consisting of gypsum, 

 thin coal beds, shale, sandstone, conglomerate, and limestone. 



On the east side of the northern peninsula the section, begin- 

 ning in the pre-Cambrian and extending into the Silurian, con- 

 sists of alternating zones of limestones, slates, sandstones, and 

 conglomerates,* the belt varying in width from nothing at the 

 south to ten miles and upward at the north. 



On the southeastern peninsula the youngest strata are of 

 Cambrian time, consisting of conglomerates, shales, and lime- 

 stones, f Beneath is the Avalonian series (Proterozoic) of 

 slates, sandstones, quartzites, and conglomerates.^ 



The interior is underlain by more or less alternating bands 

 of Paleozoic and Huronian sediments of varied character, 

 Laurentian crystallines, and great masses of post-Ordovician 

 intrusives, consisting of granite, diorite, and trap.§ 



It is readily seen from this brief description of the rocks 

 that they vary widely, which in consequence leads to decided 

 variations in topographic expression. 



Structure of Newfoundland. 



No factor has made a more decided impress on Newfound- 

 land topography than that of structure, which in its broader 

 outlines is as follows : 



On the coasts of the northern peninsula the beds depart 

 little from the horizontal, Logan | stating that "in the great 

 northern peninsula of Newfoundland, instead of undulations, 

 great lines of fracture and dislocations are observed while the 

 strata are but little tilted " and only locally does the dip rise 

 to high angles. On the northern half of the west coast the 

 beds are generally inclined southwestward and the inclination 

 may rise to as high as 30°, while on the opposite side the dip 

 varies around 20° and is south of east.T" On the east side the 

 faults, with trends approximately parallel to the Long Range, 

 have displacements exceeding 1000 feet and usually the 

 western blocks have been elevated."* On the west side faults 

 strike inland from Hawke Harbor,ft Table Point, and Port- 

 land Head,ft the displacement at Table Point being known 



* Murray, Can. Geol. Surv^., 1865. 



f Walcott, 10th Ann. Eep., II. S. Geol. Surv., p. 554, 1890. 



j Walcott, Bull. Geol. Soc. America, x, pp. 219-220, 1898. 



§ Murray and Howley, Geol. Surv. Newfoundland, 1881. 



|| Logan, Can. Geol. Surv., Appendix to paper bv A. Murray, p. 45, 1865. 



•[Murrav, Can. Geol. Surv.. pp. 9-44, 1865. 



** Logan, Ibid., pp. 872-876, 1863. 



ft Logan, Ibid., pp. 292, 877, 1863. 



