414 N. H. DARTOX — STRATIGRAPHY OF THE BLACK HILLS, ETC. 



fossils. A similar sandstone exposed along the slopes west of the Garden 

 of the Gods and, according to Willis T. Lee, also appearing in Deadman 

 creek, is presumably of the same age, for it is overlain by Ordovician 

 limestones. North of Canyon City there are basal quartzites, with an 

 overling cherty limestone which yields an upper Cambrian trilobite, 

 Pt3^choparia. 



ORDOVICIAN 



Small areas of Ordovician rocks occur in the Manitou emba} T ment, 

 Trout Creek valley, Perry park, and west and north of Canyon City. 

 In most casses they lie on a thin mass of Cambrian sandstone or quartz- 

 ite, but locally overlap on the granites and schists. In the Canyon City 

 region the Ordovician is represented by three formations, the Manitou 

 limestone, Harding sandstone, and Fremont limestone. These have 

 been described in detail by Mr C. D. Walcott * mainly in connection 

 with the occurrence offish remains, and by Dr C.W. Cross in the region 

 northeast of Caii} r on City, in the Pike's Peak folio. 



The Manitou limestone, the basal member of the series, consists of 

 fine grained pink or reddish dolomite, less than 100 feet thick, which, in 

 the Manitou region, contains Ophileta, Camarella, and other character- 

 istic Ordovician fossils. 



The Harding sandstone consists mainly of fine, even grained, granular 

 sandstone, mostly of light color, having a maximum thickness of about 

 100 feet. At Can}'on City the formation is 80 feet thick, and consists of 

 gray, reddish, and purplish brown sandstones and shales, carrying the 

 fish remains and many molluscan fossils of early Trenton age. At this 

 place it overlaps on the gneiss, but to the southward rests with apparent 

 conformity on the Manitou limestone for some distance. A small out- 

 lier of sandstone apparently of this formation was found southeast of 

 Canyon City by G. K. Gilbert. Overlying the Harding sandstone with 

 apparent conformity there occurs a bluish gray or pinkish dolomite of 

 uneven grain, known as the Fremont limestone. It is about 100 feet 

 thick in Garden park, north of Canyon City, and 270 feet near Canyon 

 City, the increased thickness being partly due to the development of an 

 upper fossiliferous member. In Garden park it is characterized espe- 

 cially by the coral Halysites catenulatus, and it also contains a molluscan 

 fauna like that of the upper Trenton in New York. Its occurrence 

 appears to be restricted to a small area in Garden park and vicinity and 

 a narrow outcrop extending southward past Canyon City. 



At Manitou and for some distance northward and in the valle} r of 

 Trout brook the lt Red beds " are underlain for some distance by the 



* Btill. fr«ol. Soc. Am., vol. ."», pp. If):!-!!!:. 



