MESA VERDE FORMATION 605 



which link them with the Mesaverde floras to the south and the beds already 

 discussed in the Raton Mesa region. Associated with these, however, and 

 tending to give them a slightly higher position, although still within the Mon- 

 tana, are such forms as BraclnjophyUum, C unmngliamites, Geinitzia, Sequoia, 

 etcetera, all of which are beyond doubt Montana types never found in the 

 Laramie. 



"A number of collections were made by J. II. Gardner in the Ignacio Quad- 

 rangle, east of Durango, (\)l()rado, from beds regarded as the 'Laramie' of 

 that area. The plants in these collections, almost species by species, are 

 identical with the forms from Dulce and near Durango, and I have no hesi- 

 tation in saying that they occupy the same stratigraphic position and are the 

 same in age, viz., Montana." 



The Lower Montana age of the principal coal-bearing formation, indi- 

 cated by the fossil shells, has already been stated in the quotation from 

 Doctor Stanton. The fossil leaves indicate the same age, although some 

 of the species occur at Coalville, Utah, in rocks generally regarded as 

 older than Mesaverde, and others in the so-called "Laramie" above the 

 Lewis shale. 



An effort was made to correlate the coal-bearing rocks of central New 

 Mexico with the Mesaverde formation of southwest Colorado, where this 

 formation was originally named. Mr. Schrader traced the typical Mesa- 

 verde from Durango eastward and southward around the San Juan 

 Basin, but he was not satisfied that the coal-bearing rocks near Cabezon 

 are to be correlated directly with the typical Mesaverde and he described 

 them as the "Lower Montana group; relation to Mesaverde unknown." 

 However, Doctor Gardner, who later examined the same rocks, referred 

 them definitely to the Mesaverde (110, 115, 116). 



The present writer visited the Durango region for the purpose prin- 

 cipally of examining the rocks originally named Mesaverde. It was 

 thought that this region would be favorable for the collection of fossil 

 plants, inasmuch as the Mesaverde coal has been extensively mined there. 

 He also examined the coal-bearing formation at Monero, Xew Mexico, 

 and was convinced, as others have been, that it is equivalent to the Mesa- 

 verde of the Durango region. However, it was noted that the Mesaverde 

 at Monero is only a few hundred feet thick, probably about the same as 

 in the Durango region, where it is only 423 feet, while the Mesaverde of 

 Doctor Gardner^s Arroyo Torreons section (116, page 178), measured a 

 few miles northwest of Cabezon, is more than 1,300 feet thick. A some- 

 what hasty examination of the rocks between ^loncro and Cabezon con- 

 vince the writer that the base of the Mesaverde as described by Schrader 

 and Gardner is essentially the same at both localities, and that the upper 

 part of it near Cabezon is probably equivalent in age to the lower part of 



