144 CAKH()NlFKK<il!S FORMATIONS AND i'AUNAS OK COLORADO. 



the 'Miuiiton liiiK'stono. and the chcrty limestone at the Iv.ise of the series in Gafd(Mi 

 I'arlv has yii^ldetl a triiohite I'h/<'Ii()j)<iri<(." 



Peale, in his report tor isT:!." ^•i\ es ;i lumiber of .seetioiis neai' Trout Creek and 

 in Manitou Park, or. as lie ealls it, Bergen Park. In the section across Trout 

 Creek, just below the canyon (sections No. 4 and 5 on page 308), the series consists 

 of (1) granite, (2) yellow sandstone, (3) pinkish sandstone, (4) dark, purplish-brown 

 sandstone, (5) green sandstone, and (6) blood-red calcareous sandstone. Of these there 

 are about WU feet. From the upper lied Llngulepis and Ohnlas are cited. Above 

 the fossiliferous horizon occur pink limestones (7) with an extensive Ordovician 

 fauna. Peale refers 6 and 7 to the Quebec gi'oup, and the sandstones below to the 

 Potsdam. The two genera cited from 6, however, are, if correctly identitied, clearly 

 indicative of Cambrian, while the fauna of 7, though not without contradictions, 

 probably indicates Ordovician. On a small stream flowing into Trout Creek (section 

 — , p. 207) he gives 40 feet of yellow, brown-purplish, and green sandstone resting 

 on a granite, which, with little doubt, represents the Can'ibrian of the preceding 

 section, and these are succeeded by 130 feet of Manitou "^ limestone. Another small 

 tributary of Trout Creek gives the following section: (1) Granite, (2) white and 

 yellowish sandstone, (3) pink sandstone, (4) dark, purplish-brown sandstone, (5) 

 green sandstone, (6) brick-red shalj^ limestone, (7) pale-pink and gray limestone, 

 (8) pink limestone (sec. 7, p. 209). The sequence here is the same as in sections 4 

 and 5 preceding, and as the limestones are said to contain the same fossils it will be 

 necessary to draw the Cambro-Silurian line at the top of bed 6, giving the Cambrian 

 a thickness of 86 feet. 



Passing now to the very margin of the Front Range, the early Paleozoics are 

 represented by the Hay den atlas as absent over all the northern portion from the 

 Wyoming line southward to Manitou Park. King, however, held the view that into 

 an unfossiliferous series of red limestones and reddish sandstones onlj 160 feet 

 thick, occurring below a thickness of Red Beds measures in which Upper Carbon- 

 iferous fossils are found, the whole of earlier Paleozoic time is condensed. This 

 series, which he correlates with the "Potsdam" of the Black Hills, he includes 

 under the Carboniferous color in two bands which extend along both flanks of the 

 Colorado Range, and on its eastern side reach a short distance into the State of 

 Colorado, where a similar area is represented (as Carboniferous) on the Hayden 

 maps. While it is possible that the series thus differentiated by King is of Cambrian 

 age, the evidence so far adduced is very slight. It nevertheless resembles lithologi- 

 cally those beds farther south along the range whose fossils seem to demonstrate 

 their Cambrian age, as well as the Cambrian of the Black Hills. 



Although not represented upon the Hayden maps, Cambrian beds probably occur 



cU. S. Geol. Geog. Surv. Terr., [Seventh] Ann. E.ept., for 1873, 1874, pp. 198-273. 



