62 



ANNALS NEW YORK ACADEMY OF SCIENCES 



Still farther east, below the junction of Long Canyon and Eio Cimar- 

 ron, the Morrison formation is exposed in an isolated mesa which stands 

 in the midst of the canj'-on. A section at this point, measured by Lee, is 

 as follows : 



Section in Canyon of Rio Cimarron east of Long Canyon 



Feet 

 Dakota (Purgatoire). Sandstone, massive, quartzitic, cross-bedded, slightly 

 conglomeratic in places. A tliin seam of blue 



clay 100 feet from the base 250 



Shales (Morrison). Colored shale containing layers of argillaceous sand- 

 stone and limestone 40 



Coarse grained loose textured sandstone 50 



Conchoidal limestone with 

 clay and coarse sand at 



the base 10 



Arenaceous shale 10 



Conchoidal limestone. ... 1 to 3 



Variegated shale 40 



Argillaceous limestone .... 3 



Shale containing irregular 



seams and masses of 



agate - like concretions, 



colored in varying shades 



of blue and pink 40 



Sandstone 5 



Red Beds. Gypsum interbedded with 



clay 20 



Red to purple sandstones 

 and shales 



■ll:il.-i^m_^i^i 





Fig. 20. — Section of the Morrison and re- 

 lated formations in Rio Cimarron Can- 

 yon, H miles east of Folsom, New Mex- 

 ico. 



1. — Purgatoire ; 2. — Morrison ; 3. — Exeter. 

 Scale, 125 feet to 1 inch. (Lee.) 



Fig. 21. — Section of the Morrison and re- 

 lated formations in the canyon of Rio 

 Cimarron east of Long Canyon, New 

 Mexico. 



1. — Purgatoire-Dakota ; 2. — Morrison ; 

 3. — Red Beds and gypsum. Scale, 125 feet 

 to 1 inch. (Ivce. ) 



