THE DENVEE FOEMATION. 159 



was published in the society's "Proceedings,"' in association with a paper 

 1>y Mr. Eldridge in which the Arapahoe formation was first described and 

 named. In revised form the same communication was later published in 

 the American Journal of Science. 2 



Since the first published descriptions of the Arapahoe and Denver 

 formations a number of articles have appeared in discussion of their age 

 or describing fossils found in them. Reference will l>e made to these 

 publications in the following chapter. 



From the foregoing historical sketch it appears thai Golden has been 

 visited by a goodly number of geologists and paleontologists who have 

 paid more or less attention to Table Mountain and its strata. It is true 

 that no very detailed work was attempted by any one of the gentlemen 

 cited, yet several of them made extensive collections of fossil plants in the 

 strata of the coal measures and of Table Mountain, and from the weight 

 that has been attached to the determinations of these plant remains it 

 would seem that the collectors must have had full confidence in the accu- 

 racy of their knowledge concerning tin- relations of the various horizons 

 from which the fossils were obtained. 



DESCRIPTION OF THE FORMATION. 

 THE BASE OF THE SERIES. 

 Character of the first sediments. The following description of the lowest 



deposits has special reference to the section more or less plainly seen 

 along the western line, at the bases of Green and Table mountains, 

 for here the sediments are more clearly typical than in the exposures 

 apparently at the base of the series which are found north of Clear Creek. 

 Here, too, the transition into higher horizons can be followed more con- 

 nectedly, and thus a characteristic section established with which other 

 outcrops ma \ be compared. The actual contact of Denver and Arapahoe 

 beds is seldom well exposed, hence a complete description of the change 

 from one to the other can not be given. The boundary line of the Denver 

 formation as drawn upon the map is approximate, being clearly established 

 at but few points. The explanation of this inability to definitely locate 



i Vmc. Colorado Sci. Soc, Vol. Ill, pp. 119-133. 



-The Denvir Tertiary formation :. Am. .lour. Sci., Vol. XXXVII, 1889, pp. 201-282. 



