GEOLOGIC FORMATIONS 741 



the "Hitka'^ and the "Mumm'' representing duplications in the section 

 and being none other than the Titkana and the Tatei respectively. 



CHETANG LIMESTONES (§ 29) 



(§ 29a.) According to Walcott, these are Middle Cambrian in age, 

 have an estimated thickness of 900 feet, and outcrop in Chetang cliff. 

 Fossils were found by Walcott in the Chetang limestones and the forma- 

 tion affords a known point from which to begin our interpretation of 

 Walcott's section of the over- and under-lying rocks. 



(§ 2%.) Though the formation can be seen and is fossiliferous at the 

 type locality, exposures are there poor, especially with regard to the 

 upper and lower boundaries, and the latter is important, since it is de- 

 scribed by Walcott as involving the contact between the Lower and the 

 Middle Cambrian. This conception of the stratigraphy differs from the 

 one presented in this paper (§§ 8, 30e). The lower part of the Chetang 

 limestones is very well exposed and is very fossiliferous at the top of 

 Mumm Peak (§§ IG, 26h, 30r/, 33c), but erosion has there removed the 

 overlying rocks. Several Albertella horizons were also found in a section 

 exposed in the gorge below Mural Glacier. 



ADOLPHUS C'HOTA") LIMESTONE (§30) 



Hota formatiou, so far as position in tlie section is concerned : Walcott, 

 Smithsonian Miscellaneous Collections, volume 57, number 12, 1913, pages 

 335, 338, and 341. (The description of lithology and the lists of included 

 fossils are derived from an exposure of the "Tah" (Mural limestone) in 

 Mumm Peak, just above the Mural Glacier, which was mistaken for the 

 Hota) (§§30(i, 32&). 



Mumm limestones, so far as both description and position in Mumm Peak are 

 concerned: Walcott, idem, pages 334, 337 (§§30^, 32c). 



Not the Mumm limestones listed as occurring near lower end of Lake Adol- 

 phus: Walcott, idem, page 330 (= Tatei, §§22 and 26&). 



Not the Mumm limestones listed as occurring in northwest base of Titkana 

 Peak: Walcott, idem, page 337 (= Tatei, §§22 and 26&). 



Hota formation, so far as position in the section is concerned : Burling, Mu- 

 seum Bulletin number 2, Geological Survey of Canada, 1914, page 109. 



Hota formation, so far as position in the section is concerned : Walcott, Prol)- 

 lems of American geology, 1915, page 179. 



(§ 30fl^.) The "Hota formation"' is described by Walcott as composed 

 of a series of "gray arenaceous limestones and siliceous shales alternating 

 with massive quartzitic sandstones," 800 feet thick and lying beneath the 

 limestones of the Chetang formation on the southwest side of Coleman 

 Brook. By definition it is the formation separating the Mahto from the 

 Chetang. 



