62 STANTON: UPPER CRETACEOUS STRATIGRAPHY 



shales may be seen at Laguna, New Mexico, about 30 miles 

 southwest of the exposures just described. Here within the 350 

 feet immediately above the Dakota (?),^ which is 85 feet thick, 

 there are three massive cliff-making sandstones instead of two, 

 and the overlying 75 feet beneath the lava cap is a sandy shale 

 with soft sandstone bands. Marine fossils are abundant and 

 characteristic so that there is ample evidence for detailed correla- 

 tion. (Section No. 4, p. 58.) 



These New Mexican exposures may perhaps all be legitimately 

 called Mancos though it may be questionable practice in the 

 localities most remote from well recognized Mesaverde. In south- 

 ern Utah where the name is not appropriate the equivalent of 

 the lower, or Colorado portion of the Mancos may still be very 

 definitely determined by means of two or more paleontologic 

 zones which are common to southern Utah and the part of New 

 Mexico which has just been discussed. Sections recently studied 

 by Richardson^ in Kanab Valley and further west in the Colob 

 plateau show a thickening of this part of the section and a greater 

 development of sand stone as compared with the New Mexican 

 section, together with the intercalation of coal beds and brackish 

 and fresh-water sediments in the basal portion. They also show 

 according to unpublished data great local increase in the relative 

 proportion of sandstone and in the total thickness of the sedi- 

 ments in passing a short distance west from Kanab Valley. 



Some of these southern Utah sections show close resemblance 

 to the Coalville section in northern Utah and it in turn has many 

 points in common with the immensely thick section described 

 by Veatch^o ^nd Schultz^i in Uinta County, Wyoming, the south- 

 west corner of the state. In the Uinta county section beneath 

 the ''Laramie" formation in descending order come the Hilliard 

 shale, consisting of gray to black sandy shale and shaly sandstones 



* Darton has published a section of the Cretaceous rocks exposed 2 miles north- 

 east of Laguna (U. S. Geol. Survey Bull 485, p. 60) in which numbers 8 and 9 cor- 

 respond to the Dakota(?) of my section. The underlying rocks, over 300 feet in 

 thickness are suggestive of Morrison. 



9 U. S. Geol. Survey, Bull, 341, pp. 379-400. 



10 U. S. Geol. Survey, Prof. Paper No. 56. 



11 Ibid., Bull 316, pp. 212-241. 



