DESCRIPTIVE details: RIO TUERCO FIELD 



627 



Feet Inches 



Shale 2 6 



Coal 1 1 



Shale, carbonaceous 9 



Shale 1 6 



Coal 5 



Shale, carbonaceous f? 



Coal 5 



Shale, carbonaceous 2 



Coal 3 



Shale, carbonaceous 3 



Sandstone, coarse-grained 2 



Shale, carbonaceous 3 



Coal 1 2 



Shale, carbonaceous 15 



Coal 5 



Shale, carbonaceous 4 



Coal 1 9 



Shale, sandy, carbonaceous 8 



Shale, sandy 1 



Shale, carbonaceous 2 6 



Sandstone, coarse-grained, gray 3 



Shale, carbonaceous, chocolate-colored 5 



Coal 2 



Shale, carbonaceous, chocolate-colored 1 6 



Sandstone, coarse-grained, massive, gray 30 



Shale, with layers and lenses of yellow sandstone and earthy 

 limestone containing Halymenites major Lesq. ; Ostrca congesta 

 Conrad; Inoceramus sp. ; LitJiophagus 1 sp. ; Lamna sp, (U. S. 



G. S. locality No. 7190) 400± 



Sandstone, coarse-grained, yellow to gray ; contains the following 

 fossil leaves: Quercus sp. serrate, new; Ficus n. sp- (3-nerved 

 type) ; Ficus sp. ; Dryophyllum falcatmn Ward (Point of Rocks 

 species) ; Dalhergia n. sp. (same as Hagan No. 6030) ; Salix 

 stantoni 1 Kn. ; Vihurnum 'i proMematicus Kn. (U. S. G. S. lo- 

 cality No. 6035) ; 25± 



Shale, containing one bed of coal 6 feet thick and several thin 



beds 100± 



Sandstone with layers of shale and lenses of impure limestone, 



fossiliferous, but no collections made 172 



Sandstone, massive, gray, with lenses of impure yellow limestone 

 near the top, containing Ostrea sp, ; Inocemmus sp. (very thick- 

 shelled form) ; Ciicullcea sp. ; Cardium sp. ; Tellina sp. ; Liopistha 

 undata M. & H. ? ; Mactra sp. related to M. formosa M. and H. ; 

 Mactra sp., large form ; Volutomorpha novimexicana Herrick & 

 Johnson; Baculites sp. ; Placenticeras planum Hyatt; Lamna sp. 



(U. S. G. S. locality No. 7188) 110 



Shale, carbonaceous, chocolate-colored 27 



Sandstone, yellow, and shale, in alternating layers 235 



