326 Richardson — Stratigraphy of the upper Carboniferous 



three formations called the Cibola beds, the Alta beds, and 

 the Cieneguita beds, and named, the whole the Chinati series. 

 These rocks are delimited below bj intrusive granite and are 

 unconformably overlain by Lower Cretaceous strata. The 

 fossils obtained from Udden's Chinati "series," Dr. Girty 



Fig. 1. 



Fig. 1. Map of New Mexico and west Texas showing location of sections. 



informs me, are more suggestive of the Hueco fauna than of 

 the typical G-uadalupian. Eecently Stuart Weller,* in describ- 

 ing some crinoids from the Cibola beds, has referred to them 

 as Permian. Correlation by stratigraphic tracing is precluded 

 by the isolated occurrence of the rocks in the Chinati Moun- 

 * Journal of Geology, vol. xvii, pp. 623-635, 1909. 



