Art. IX.] Herrick-Johnson, Geology of the Alhuquerque Sheet 197 
sidered by most geologists as the standard for the classification 
of the Upper Cretaceous formations in America : 
Upper Missouri Section. 
rrj in 
(Meek and Hayden.) 
Td 
t/2 XJ 
W H 
Fox Hills Grp, 
Form. No. 5. 
Gray, ferruginous and yellowish sand- 
stone and arenaceous clays, containing 
Belemnitella bulbosa. Nautilus dekayi, 
Placenticerus placenta, Scaphites con- 
radi, Baculites grandis, Auchiera amer- 
icana, and a great numberjof other mul- 
luscan fossils. 
G-h 
0 
0 
c/2 
•ii 
<L) 
C/3 
Dark gray and bluish plastic clays, 
containing Nautilus, Placenticeus pla- 
centa, Baculites ovatus and compressus, 
Scaphites’nodosus, Inoceramus sagenus. 
k. 
02 
a, 
Dh 
Ph 
0 ^ 
Middle^zone nearly barren of fossils. 
« 
Ft, Pierre 
Form. No 
Lower fossiliferous zone, containing 
Ammonites complexus, Baculates ovatus 
B. compressus, several species of Heter- 
oceras, Inoceramus tenuilineatus, bones 
of Mososaurus, etc. 
0 
0 
Dark bed of very fine unctuous clay, 
containing much carbonaceous matter, 
with veins and seams of gypsum. 
Niobrara Div. 
Form. No. 3. 
Lead gray calcareous marls, weather- 
ing to a yellowish or whitish chalky ap- 
pearance above. Containing remains of 
fishes and Ostrea congesta, also several 
species of Textularia. Passing down 
into light yellowish, whitish limestone, 
containing numbers of several species 
of Inoceramus, as well as Ostrea con- 
gesta, fish scales, etc. 
200 ft. 
Lower Series. 
Ft. Benton Grp. 
Form. No. 2. 
Dark gray laminated clays, sometimes 
alternating near the top with seams of 
light colored limestone. Fossils^ Ino- 
ceramus problematicus, I. tennicosta- 
tus, Ostrea congesta, Veniella mortoni, 
Prionocyclus woolgari, Scaphites warr- 
enanus. Nautilus elegans, etc. 
800 ft. 
' 
6 
6 0 
Yellowish, reddish and white sand- 
stones, at places with alternations of 
various colored clays and seams of im- 
pure lignite. Fossils, Pharella ? dako- 
tensis, Trigonarca siouxensis, Cyrena 
arenarea, Margaretana nebrascensis, 
impressions of leaves, etc. 
Wh 
0 
0 
0 
Q Ph 
