20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



Obolus cf. tctonensis Walcott 

 Lingulella ibicits Walcott 

 Billingsella archias Walcott 

 Eoorthis ochus Walcott 

 Syntrophia cf. isis Walcott 

 Syntrophia cf. calcifcra Billings 

 Platyceras 

 Straparollus 

 Agnostus sp. 

 Symphysurina ? sp. 



SUMMARY OF SECTION OF MONS IN SINCLAIR CANYON SECTION 



Feet Meters 



1. Limestone with shaly partings : 545 i66.l 



2. Concealed (estimated) 356 108.5 



3. Limestone and shales 1,705 519-7 



4. Shales with little limestone 1,220 371.9 



Total Mons 3,826 1,166.2 



UPPER CAMBRIAN 



Lyell ? Formation (See p. 39) : 



Beneath the base of the Mons at the Radium Hot Springs bathing pool there 

 is a thick-bedded, coarse, steel gray limestone that differs in character from 

 the Silurian and all other limestones in the Sinclair Canyon section. It is 

 similar to a limestone at the base of the Mons in the Stoddart-Dry Creek 

 section 5.5 miles (8.8 km.) to the south, and in the Sabine Mountain section 34 

 miles (54.7 km.) further south at the south end of the Stanford Range. The 

 stratigraphic position of this limestone is referred to on page 39. 



I. Massive rough weathering cliff^forming semi-crystalline ^^ ^ ^^^ 

 gray magnesian limestone in layers 2 to 20 feet (.6 to 

 6. m.) in thickness 860 262.1 



Strike N. 15° W. Dip 45° S. 75° W. 



The lowest layers exposed strike N. 5° W. and dip 50° E. 



This limestone is here cut off below by a great fault that 

 brings the Red Wall Breccia of presumably Silurian age 

 against it. The fault is vertical and strikes N. 15° W., 

 which causes it to cut obliquely across the Lyell lime- 

 stone tmd into the lower Mons shales a short distance 

 north of the canyon. 



Note. — The hot springs originate on the line of the Red Wall fault and the 

 water running through breaks in the upper beds of the Lyell ? limestone comes 

 out on the contact between the limestone and the lower Mons shales just 

 above the bathing pool. 



