Assodation of American Geologists and Naturalists. 175 



Prof. Beck read the title of a paper " on some Trappean miner- 

 als and the general geological conclusions to be drawn from their 

 history." 



The committee on the time of meeting for 1843, reported the 

 fourth Wednesday of April next, which was accepted. 



Prof W. B. Rogers read a paper " on the Age of the Coal 

 Rocks of eastern Virginia." He described these strata as occu- 

 pying parts of Chesterfield, Powhatan, Amelia, Henrico, and 

 Goochland counties, and lying in basins of granite, the principal 

 coal seam being separated by only a few feet from the floor of 

 primary rock. In some places near the margin of the field, where 

 alone they have been explored, the thickness of these coal rocks 

 is upwards of eight hundred feet, but towards the centre of the 

 principal basin it is probably somewhat greater. Throughout 

 much of this depth they consist of coarse grits, often composed 

 of the materials of granite so little worn as to present the aspect 

 of this rock in a decomposing state. In this paper Prof. R. shows, 

 on the testimony of fossils, and especially the vegetable impres- 

 sions found in the grits and slates associated with the coal, that 

 these rocks instead of being as had been hitherto supposed of 

 even older date than the great carboniferous formation of the 

 west and of Europe, belong in fact to a much later period and 

 correspond nearly if not accurately with the bottom of the oolite 

 formation of Europe. The prevailing fossils are of the genera 

 Equisetum, Tceniopteus, and Cycadites or Pterophyllum, and 

 either agree specifically or correspond nearly with those of the 

 oolite coal of Brora and the equivalent beds at Whitby and other 

 places. Prof. R. laid much stress on this determination as sup- 

 plying one of the links in the geological series not hitherto dis- 

 covered in this country, and as presenting^a striking analogy with 

 the abnormal development of the lower oolite in certain parts of 

 Europe. At the conclusion of the paper. Prof. R. stated that 

 from the fossils he has discovered in a particular division of the 

 new red sandstone of Virginia, he expects ere long to be able 

 confidently to announce the existence of beds in that formation 

 corresponding to the Keuper in Europe. 



Prof. Wm. B. Rogers communicated a paper " on the Porous 

 Anthracite or Natural Coke of Eastern Virginia." In this paper 

 Prof. R. investigates the cause of the peculiar texture and com- 

 position of this material, and points out the forms of vegetation 



