510 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



of the full discovery of the facts needed for the stratigraphy of the series and 

 the structural geology of its rocks in these areas. It is to be understood that 

 the following statements should be subject to careful revision through future 

 field work. 



Detailed Sections and the Fossiliferous Horizons. — Neither I ase nor top 

 has been found for the series. Partial sections have been roughly measured and 

 these will be described in brief form. On the basis of these as well as a multi- 

 tude of details, isolated facts entered in the field note-books, a provisional 

 columnar section embracing the rocks actually observed east of Cultus lake, 

 has been constructed. 



Section I. 



About one mile west-southwest of Monument 48, beds which are believed to 

 be the youngest exposed members of the Chilliwack series are unconformably 

 overlain by grits and conglomerates belonging to the Tamihy Cretaceous ( ?) 

 formation. From that point to the ridge of Church mountain two miles north 

 of the Boundary line the exposures are unusually good for this region and a 

 partial section of the series has there been made with some degree of confidence. 

 The order is as follows :— 



Top, unconformable contact with Tamihy formation. 



a. 50 (or more) feet. — Quartzitic sandstone. 



b. 20 " Dark gray argillite. 



c. 50 " Light gray limestone, bearing fossils with numbers 1506, 1509 10. 



d. 60 (estimated) " Gray calcareous quartzite and dark gray, calcareous argillite. 



e. 2,000+ " Andesitic flows., tuffs and agglomerates. 



/. 200 " Gray and brownish shale and sandstone ; thin conglomerate 



bands; crumbling, thin-bedded; highly fossiliferous. Col- 

 lection Nos. 1512, 1514. 



g. 600 (estimated) " Light gray, generally crystalline limestone, with fossils, No. 



1513. 



2,980 feet. 



Base concealed. 



Tor the determination of these as well as of the other -collections made in 

 the Chilliwack rocks, the writer is indebted to the great kindness of Dr. George 

 IT. Girty, and Dr. E. S. Bassler. The latter determined the bryozoa; the other 

 genera were determined by Dr. Girty. The results may be quoted from Dr. 

 Girty's letter, in terms of the collection numbers: — 



No. 1506. About 900 yards south of the Boundary slash and 1,500 yards 

 southwest of Monument 48. 

 Fossils : crinoidal fragments. 



No. 1509. 100+ yards southwest of Monument 48. 

 Fossils : 



Zaphrentis sp. 

 Campopliyllum sp. 

 Eu'omphaJus sp. 



