TO JUNCTION OF GRAND AND GREEN RIVERS. 87 



2. Dark-blue calcareous shales with bands of dove-colored limestone, weathering 

 light-ash, with thinner layers oi' brown sandy limestone. 



In the shales are imbedded great numbers of Gr//i>l/(c- I'itcheri, generally of small 

 si/,o but beautifully perfect They exhibit a great variety of form, some being very 

 high and narrow; others broader, like the typical G. Pitcheri; others nearly orbicular 

 like G. dilatntn of the Oxford clay; others still broader, with a transverse diameter con- 

 siderably greater than the antero-posterior. Between these various forms are connect- 

 ing links which seem to prove that all belong to one species. The dove-colored lime- 

 stones, here as on the (Jhama and Canadian, contain almost exclusively Inoccramtiy 

 problematictis, and also exhibit the peculiar fracture noticed in the localities mentioned 

 above, and others, on exposure, cracking horizontally into concavo-convex chip-like 

 fragments, having sharp edges. 



The ferruginous layers represent the fish-bed of the Pagosa, the Chama, the 

 Canadian, &c., a clearly defined geological horizon throughout all the Cretaceous area 

 of New Mexico; they contain hen; (Mira liii/nhri.^ and many fragments of Inoceramus 

 I. i>i-i)l>/t'iiiiifi<-n* and a much larger species probably not described. 



.'!. Coarse yellow sandstone, often a conglomerate, containing impressions of dico- 

 tyledonous leaves, Salix, &c., and thin bands of lignite. 



4. Greenish or light-brown soft calcareous sandstone, with local layers of blue 

 clay-shale and thin seams of lignite ; no fossils observed. 



5. Thick-bedded light-yellow or white sandstone, locally coarse or fine, some- 

 times a conglomerate containing quart/ pebbles, generally fine-grained and nearly 

 white; no fossils. 



6. Green or purple clay stones and shales. 



7. Soft greenish sandstone. 



Most of the strata enumerated above are exposed in the cliffs bordering the valley; 

 for several miles are entirely unbroken, conformable throughout, and have a gentle dip 

 to the west. The facts here observed are of special interest as deciding" beyond all 

 appeal the question of the relative age of the sandstone group containing angiosperm- 

 ons leaves, so marked a feature in the geology of New Mexico. This is but one of 

 the great number of cases where these sandstones were found overlaid by strata con- 

 taining well known Cretaceous fossils. It is to be hoped that this mooted question 

 will now be considered settled, since it must be so in the mind of every honest inves- 

 tigator. 



From the summit of the hill from which the preceding section was taken, we 

 obtained a magnificent view of a wide extent of country lying on every side of us. In 

 the east the Sierra de la Plata rose as a high and unbroken wall, presenting a more 

 varied outline than when seen from the other side ; south of the Sierra, the puerta 

 through which we had passed; beyond this, stretching far off southward, the green 

 slopes and lofty battlements of the Mesa Verde beetling over the plain like some high 

 and rock-bound coast above the level ocean; south, and near us, the miniature peak 

 and chain of La Late ; far more distant, the Sierras Carriso and Tunecha in the Navajo 

 country ; occupying the whole western horizon the monotonous expanse of the Sage- 

 plain, beyond which rose the low summits of the Orejas del Oso, Sierra Abajo, and 



