K^lSfS^S CITY 



Review of Science and Industry, 



A MONTHLY RECORD OF PROGRESS IN 



SCIENCE, MECHANIC ARTS AND LITERATURE. 



VOL V. MAY, 1881. NO. 1, 



GEOLOGY. 



THE NIOBRARA GROUP. 



BY CHAS. H. STERNBERG. 



The rocks of Cretaceous No. 3, or Niobrara group, consist of an upper strat- 

 um of red, yellow or white chalk, underlaid by great beds of blue shale. There 

 is no paleontological difference between the strata, as the same animal remains 

 are found in both. These beds are of great value to science, as they contain the 

 remains of animals that once inhabited the cretaceous ocean. Perfect skeletons 

 are found of huge saurians eighty feet in length. What a field for the imagina- 

 tion of the student, to people the old cretaceous seas with animals restored from 

 their buried relics ! I now in imagination walk the old cretaceous beach ; I hear 

 the rush of mighty rivers, as, laden with the debris of the carboniferous hills, 

 they pour into the ocean, depositing their loads of soft mud that is to cover and 

 preserve the remains of animals living in these waters. Far out at sea, I "ob- 

 serve a huge snake-like animal, with head erect, full twenty feet in air, gazing 

 into the depth below." The fish that meets his eye will soon fall a victim to his 

 voracious appetite. Another monster of the deep grandly exposes a length of 

 eighty feet ; as he lies stretched on the waters an enemy in the distance attracts 

 his attention and he prepares to offer battle ; his four powerful paddles begin to work, 

 and that vast mass of animal life commences slowly to move; gradually it gains 

 more speed as]the paddles move more rapidly ; his huge tail, acting like a screw 

 propeller of some steamboat, augments his speed and guides him toward his prey. 



The water boils behind him. It matters not how large the animal may be that he 

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