338 ANNUAL OF SCIENTIFIC DISCOVERY. 



River Saskatchewan.* To the west, from the Red River, it extends to and 

 beyond Santa IV, embracing the head waters of the Colorado, and, stretch- 

 ing north-west, reaches the head waters of the Columbia, as well as those of 

 the Missouri River. Following a south-western direction from Red River 

 through Texas, it crosses the Rio Grande into New Leon, and thence south 

 through St. Luis Potosi, it passes indefinitely into Mexico. 



In all the great extent of this formation there is evidence of the cretace- 

 ous period, while most of the species differ from our eastern fauna, as the 

 lithological characters do in the rocks and sediments. In New Jersey, the 

 greensand beds are but slightly calcareous, the limestone, lying above, hav- 

 ing about 80 per cent, of lime. In North and South Carolina, it is, accord- 

 ing to Prof. Tuomey, " 25 to 30 per cent, of the mass/' but in Alabama it is 

 " highly calcareous." This vast extent of a simultaneous deposit of this 

 kind, is calculated to excite the greatest interest, when we consider how 

 much it affects our agricultural prospects. 



In 1840, Prof H. D. Rogers published his Report on the Geology of New 

 Jersey, in which he separated the cretaceous group into five divisions, under 

 the name of " the upper secondary series, embracing the greensand forma- 

 tion." 1. A group of sands and clays extremely white and pure. 2. A 

 mixed group, consisting of greensand, alternating with, and occasionally 

 replaced by, layers of a blue, sandy, micaceous clay, the so-called " green- 

 sand formation." 3. A yellowish, granular limestone, having a profusion 

 of organic remains. 4. A yellow, very ferruginous coarse sand, with some 

 fossil shells of the green sand formation. 5. A coarse, brown, ferruginous 

 sandstone, sometimes passing into a conglomerate. Subsequently, in John- 

 ston's Physical Atlas, 18-35, under the name of '"Newer Mesozoic," he con- 

 tinues these divisions, the whole thickness of which he presumes to be a 

 thousand feet. Prof. Tuomey, in the tables of his geological survey of 

 South Carolina, in 1848, calls the New Jersey deposits " upper greensand; " 

 those of South Carolina, " the gault; " those of Alabama, the lower green- 

 sand, equivalent to the Neocomien of the French geologists. 



In 18-54, Messrs. Hall and Meek made a communication to the American 

 Academy of Arts and Sciences, on some fossils from the Cretaceous Forma- 

 tion of Nebraska. This they divide into five sections. 5. Arenaceous clay, 

 passing into argillo-calcareous sandstone. 4. Plastic clay, the principal fos- 

 siliferous bed of the upper Missouri. 3. Calcareous marl, containing Ostrea 

 conyesta, etc. 2. Clay, containing few fossils. 1. Sandstone and clay. 



In 18-35, Mr. Marcon publised, in the Bulletin of the Geological Society of 

 France, an account of the Geology of the United States, in the cretaceous 

 division of which (page 70), after giving to Prof. Vanuxem the credit of being 

 the first to detect this group in the United States, he says that it may be 

 divided provisionally into " three great groups," which have been named in 

 Europe, 1st, le Neocomien; 2d, le gres vert superieur et la craie marneuse; 

 3d, la craie blanche. 



In March 1856, Mr. Meek and Dr. Hayden published their section of the 

 Cretaceous formation of Nebraska. 5. Gray and yellowish arenaceous clays, 



* See the map of Nebraska, by Lieut. "Warren and Dr. Hayden, with explanations 

 by the latter, who has done so much for the geology of the Western Territories; also 

 the excellent map of Hall and Lesley, in Major Emory's Report on the Mexican 

 Boundary Survey, and Prof. Hall's Report of the Geology of the Boundary, in the 

 same volume. Also, the various papers of Meek and Hayden. 



