1()!S C'AKKONIKEKOUS KOKMATK INS AND FAUNAS OF CiiLdUAUO. 



Millsiij) liiiiostoiu', is ovoi'laiii i\v the Red Beds. Witli No. S will probulily go No. 7, 

 iiiul iKissihly also li. .'). iiiid 4, tii()iij;li it seems to nie rather jirolialile, by arialo^'v with 

 neifi'hhoriiio- sections, tluit 2 and 13 at least are pre-C 'ari)onifei<iiis and rejiresent the 

 Cambrian. No. 1 also suggests the Harding sandstone of the Pueblo quadrangle. 



'i'he beds which Lee refers to the Carboniferous have at the base -iO feet of 

 coarse, green, crundjling .sandstone, conglomeratic in places, and mottled in varjdng 

 shades of red and gray. Above this sandstone apjDear 10 to 15 feet of deep-red to 

 white cherty limestones alternating with red shales. Near the top of this series 

 Carboniferous fossils were obtained. Above these occur several hundred feet of 

 coarse-gi-ained sandstones and coi'iglomerates, which appear to be perfectly conform- 

 al)le with the fossilifei'ous series. It is clear that the siliceous .series last referred to 

 is not a part of the Millsap limestone, but probably I'epresents a portion of the Foun- 

 tain lieds above. The sandstones at the base probahlj- correspond to those mentioned 

 by Peale, which I have referred, upon somewhat doul)tful evidence, to the Cambrian. 

 The Millsap limestone, then, would embrace merelj- the small thickness of cherty 

 limestone in the middle of Lee's Carboniferous. It seems probable from these sec- 

 tions that the Millsap, small as is its thickness in Garden Park, in the Pikes Peak 

 (juadrangle, is still further reduced in Perry Park. 



The Millsap is apparently absent in Manitou Park, the Fountain beds coming- 

 down upon the Ordovician; but at Glen Erie," near Colorado Springs, the whole or 

 part of a series of gi'ay, purplish, and yellow limestones, 279 feet in thickness, may 

 belong to it. Mr. A. W. Grabau informs me that he has collected a Carboniferous 

 fauna from the uppei' portion. Beneath this bed occur red shaly limestones with 

 Ordovician fossils (the Manitou limestone), and above it the Red Beds. 



Some beds lielonging to the Millsap limestone are apparently included by 

 Walcott in a section which he describes from Harding's quarry, near Canyon. 

 Here it is reported as 15 to 30 feet in thickness, and as consisting of impure, varie- 

 gated, banded limestone, with interbedded argillaceous beds. Sjyirifer rookymon- 

 tmius and Sem inula HuMlUta are cited. 



Gilbert recognized the Millsap limestone in the Pueblo quadrangle, where it 

 consists of gray and purple limestone, with some shale, especially in the lower part. 

 These strata are 200 feet thick, and are said to rest conformably upon the Harding- 

 sandstone. Near the middle w^as found Spii'ifer rocJcymontanus, a species which 

 \is cited from the tj'pical exposures in Garden Park. It seems probable, there- 

 jfore, that the upper part of Gilbert's Millsap is correctly correlated. As at the 

 Inearest outcrops of these formations, viz, those at Can3'on, the Harding sandstone 

 is followed by 270 feet of Fremont limestone and but 15 to 30 feet of Millsap, it is a 

 little unexpected to iind that the thick Fremont has vanished, and that the Millsap 



nU. S. Geol. Ge'og. Surv. Terr., [Seventh] Ann. Kept., for 1873, 1874, p. 201. 



