107 



The cretaceous group, which occupies so extensive an area on the 

 Upper Missouri, has been separated into five divisions, which present 

 well marked lithological differences and contain, for the most part, 

 distinct species of organic remains. 



Vertical section of the cretaceous formations of Nebraska Territory, so 



far as determined. 



Gray and yellowish arenaceous clays, and 

 sandstones, sometimes weathering to a pink 

 color ; containing Belemnitella bulbosa, Nauti- 

 lus Dekayi, Amvionites placenta, A. lobatus, Sca- 

 phites Conradi, Baculttes ovatus, and great uum- 

 bers of other marine mollusca. 



Moreau trading post 

 and under the tertiary 

 at Sage and Bear cr ' ks. 



Fox hills. 



Bluish and dark gray plastic clays, con- 

 taining Nautilus Dekayi, Ammonites placenta, 

 Baculites ovatus, and B. compressus, with nu- 

 merous other marine mollusca — remains of 

 Mosasauras. 



Great area about Ft. 

 Pierre and along^ the 

 Missouri below there. 

 Under No. 5, at Sage 

 and Bear ci'ks. Great 

 Bend of the Missouri. 

 Near Milk and Muscle 

 Shell rivers. 



Dark, very fine xinctuous clay, 

 containing much carbonaceous mat- 

 ter, with veins and seams selenite, 

 sulphuret of iron, fish and scales, 

 (local.) 



Bluffs along the Mis- 



T I 1 1 J.U i souri, below the Great 



Lead gray calcareous marl, weath- ' „ j tt- x j i. r>- 

 1 ^ 1, ■ V i- 1 CI 1 I Bend. Extends to Big 



enngabove to a yellowish tmt. Scales 1 „• • . 



, ,, . ^ f. , /-> , ; Sioux river, and oc- 



and other remains of fishes — Ostrea 1 , Ii , . . 



1 J • i. curs along the latter 



congesta — passing downwards into . ° 



•^ ^ ^ stream. 



Light gray or yellowish limestone, 

 containing great numbers of Inocera- 

 mus problematic us, fish scales, and 



Ostrea congeda. 



Dark gray laminated clay scales and other 

 remains of fishes, small Ammonites, Inoce- 

 ramus problematicus ?, Serpula, small oyster- 

 like 0. congesta, &c , &c. 



Along the Missouri 

 Bluffs, from ten miles 

 above James river to 

 Big Sioux river. 



o "5 



lello-vish and reddish friable sandstone, x- „ ii i.\ c 



.,, ,, .. ^ , , J 1 -i.- I 1 Is ear the mouth of 



withalternalionsof dark and whitish clays. I T>. o- • j 



o ] 1 1 r • 1- -i. f -1 I Big Sioux river, and 



Seams and beds of impure lignite, fossil , ° xu j 



, . . r 1- X 1 J 1 between there and 



wood, impressions of dicotyledonous leaves; L-, ., t,, a- -wt 

 eiD, 1 r< ■ e t I Council Blufis. Near 



bolen, Pectunculus, Cypnna, &c. Lower ere- t j-xi • o 

 . < jf ' Judith river.? 



taceous. I 



2 a 



