STRATIGRAPHIC POSITION OF JUDITH RIVER FORMATION 643 
Claggett 
Formation 
Eagle Forma- 
tion 
No fossils 
Dark 
Benton 
Shales 
c) Light-colored shales or sandy clays with band 
of brown sandstone containing J ancredia americana 
invmiddless Top volamarines 075.0... 4 ee ae 
b) Yellowish-brown sandstones, generally soft, but 
with harder layer and lenses, with Tancredia ameri- 
cana, Cardium speciosum, Tellina equilateralis, Lio- 
pistha (Cymella) undata, Lunatia, subcrassa, Baculites 
sp., and fragment of vertebrate jaw................ 
a) Dark shales with concretions bearing Bacu- 
lites ovatus, B. compressus, Nucula cancellata, Leda 
(Yoldia) evansi, and Gervillia borealis. These shales 
weather much as the Bearpaw, but with a reddish 
tinge. The concretions are different with fewer 
fossils and not so great a variety. These beds become 
lighter toward the top, the upper 50 feet containing 
two seams of thin brown sandstone, each 2 to 3 feet 
e) Cross-bedded and finely laminated sands with 
thin seams of lignites, in places becoming more mas- 
SIV ee eee ese this Mt ears aie dl Paea shah eae taiees 
c) Heavy-bedded buff sandstones, soft at base, 
but harder above, and with indurated lenses and num- 
erous large concretions, weathering brown at the top. 
The thickness of 5 and c is very variable........... 
b) Heavy-bedded buff sandstones with lenses of 
lignite and shales sometimes exhibiting cross-bedding 
a) Regularly-bedded buff sandstones with several 
thingseams,ofidarkyshalestn see ean sayeth. 
Total thickness of Eagle formation............. 
Baculites and other invertebrates in concretions, 
and containing several layers of sandstones in upper 
100 feet. The following fossils were found in these 
shales near the base: Inoceramus sp., fragments of a 
thick-shelled form; Prionotropis(?) sp., fragment; 
Scaphites ventricosus; Baculites sp., a slender, strongly 
nodose form. Several genera of invertebrates not 
specifically determinable were collected in the upper 
DOLELOM A ca afdtcareatrnre Moet AVON ells en ane NAN neat | 
FEET 
50 
300-400 
379-479 
125 
40 
50 
30 
20 
265 
300 
