TO JUNCTION OF GRAND AND GREEN RIVERS. 43 



ages they have served as hinges upon which the great plates of the earth's crust 

 turned, as, in repeated elevations and depressions, the angles which they inclose have 

 been ever varying. 



The following detailed sections of the Carboniferous strata, exposed in the hills 

 immediately back of Santa Fe, will 1)0 read with interest by all those who are familiar 

 with the Carboniferous rocks of the valley of the .Mississippi. 



Section of strata at Santa Fe. 

 No. 1. 



Feet. 



1. Soft reddish-yellow conglomerate . - - 



2. Red shale and sandstone, without fossils 45 



3. Yellow magnesian, shaly limestone, containing large numbers of Orthisina 



umbraculum and Productus setnireticulatus - - . 8 



4. Red and yellow shale without fossils . . 25 



5. Red and yellow argillaceous shale, with thin bands of ferruginous sandy lime- 



stone 20 



G. Yellow and pink shale, with bands of calcareous nodules 8 



7. Yellowish-pink (flesh-colored) limestone, containing Prod actus nodosus, Spirifer 



earner atus, lictzia mormoni, &v, 7 



8. Red and yellow shale, with layers of limestone nodules. . . . 15 



!). Yellow limestone, with partings of shale. - . — - 6 



10. Soft red shales, with two bands of intensely hard, grey, quart/ose, tine con- 



glomerate, with numerous but obscure impressions of stems of plants -If) 



1 1. Yellowish-blue compact limestone, with Productus setnireticulatus, Spirifer cam- 



eratus ) etc., in great numbers 8 



12. Purple, pink, and yellow shales, with thin bands of ferruginous limestone, con- 



taining the same fossils as the bed above 50 



13. Coarse, brown, sandy limestone, full of crinoidal columns . 16' 



14. Coarse, gray sandstone 5 



1 5. Gray clay 3 



16. Coarse, reddish sandstone. . . 7 



17. Coarse, massive, silicious sandstone, with large grains of quartz, containing 



Spirifer came rat as 10 



18. ( \ ray clay - 3 



19. Gray limestone, with Productus semireticulatus^ P. nodosus, &<• 8 



20. Pinkish and variegated sandstone 12 



21. Cray Limestone I 



22. Ferruginous and micaceous sandstone G 



23. Ferruginous foliated limestone, with Orthisina umbraculum, Spirifer cameratus, 



. 1 thyris Roysu — 7 



2 I. Reddish-gray, compact limestone, with Spirifer cameratus, S. lineaius, Produc- 

 tus nodosics, P. Rogersi, P. scabriculus, P. semireticulatus, Athuris subtUita, 

 <£e - 5 



