86 PROCEEDINGS OP THE WASHINGTON MEETING 



lack of fossils makes a paleontological differentiation difficult. The total thick- 

 ness of the Cretaceous appears to be 7,000 feet. 



Presented in abstract extemporaneously. 



SEDIMENTARY SUCCESSION IN SOUTHERN NEW MEXICO 

 BY N. H. DARTON 



(Abstract) 



In connection with the study of the Red Beds and associated strata in New 

 Mexico many stratigraphic data have been obtained of the entire Paleozoic 

 and Mesozoic succession. The distribution and local variations of the forma- 

 tions present some novel features which throw light on the geologic history of 

 the region. Especially notable are the overlap relations of the formations of 

 Carboniferous age, particularly the Pennsylvanian division, which overlaps 

 Cambrian, Ordovician, Silurian, Devonian, and Mississippian rocks. The rela- 

 tions of the Red Beds of Permo-Pennsylvanian and Triassic age were studied 

 in detail. Considerable new evidence was also obtained on the distribution of 

 the Comanche group and overlying formations of Cretaceous age. 



Bead by title in the absence of the author. 



DIVISIONS AND CORRELATIONS OF THE DUNKARD SERIES OF OHIO * 

 BY CLINTON K. STATJFFEK 



The youngest Paleozoic deposits in Ohio have long been known as the Upper 

 Barren Coal Measures and more recently as the Dunkard .series. These rocks 

 are quite extensively developed in adjacent States to the east and have doubt- 

 less been removed by erosion over wide areas in which no trace of them now 

 remains. It is only the comparatively thin western edge of the Dunkard that 

 extends into Ohio and covers a rather narrow strip along the Ohio River from 

 Jefferson to Meigs county. At the northern end of the Ohio portion of the 

 Dunkard basin there is ho appreciable break between the Monongahela and 

 the overlying Dunkard series. From the stratigraphic relations the basal 

 plant beds (Cassville) ought therefore to continue the same flora that flour- 

 ished during the formation of the preceding Waynesburg coal bed, but appar- 

 ently such is not the case. Over the southern half of the basin, however, the 

 Waynesburg sandstone usually rests directly on the Monongahela with marked 

 unconformity, the Cassville, the Waynesburg coal, and a portion of the under- 

 lying shales usually being absent. Unconformities in a series of rocks, such 

 as the Dunkard, probably do not have any very great significance ; in fact, 

 they occur at several horizons within the series ; but the development of the 

 coarse massive Waynesburg sandstone, often a true conglomerate, over much 

 of the unconformity between Monongahela and Dunkard may be indicative of 

 changed conditions. 



The Dunkard series of Ohio may be divided, as in Pennsylvania and West 

 Virginia, into the Washington and the Greene formations. The former begins 



* Published with the permission of the State Geologist of Ohio. 



