HISTORICAL GEOLOGY 83 



the strata of the Connecticut valley to the New Red 

 Sandstone, a term that then covered both the Permian 

 and the Triassic. In 1842, W. B. Rogers referred the 

 heds to the Jurassic, on the basis of plants from Virginia. 

 In 1856, W. C. Redfield (1789-1857), because of the fishes, 

 advocated a Lias, or Jurassic age, and proposed the 

 name Newark group for all the Triassic deposits of 

 the Atlantic border. More recently, on the basis of the 

 plants studied by Newberry, Fontaine, Sturr, and Ward, 

 and the vertebrates described by Marsh and Lull, the 

 age has been definitely fixed as Upper Triassic (see 

 Dana's Manual of Geology, 740, 1895). 



Unearthing of the Paleozoic in North America. 



Permian of the United States. In Europe, previous to 

 1841, the formations now classed as Permian were 

 included in the New Red Sandstone, and with the Car- 

 boniferous were referred to the Secondary. In that 

 year Murchison proposed the period term Permian. In 

 1845 came the classic Geology of Russia in Europe and 

 the Ural Mountains, by Murchison, Keyserling, and De 

 Verneuil. In this great work the authors separated out 

 of the New Red the Magnesian Limestone of Great Brit- 

 ain and the Rothliegende marls, Kupferschiefer, and 

 Zechstein of Germany, and with other formations of the 

 Urals in Russia, referred them to the Permian system. 

 This step, one of the most discerning in historical geol- 

 ogy, was all the more important because they closed the 

 Paleozoic era with the Permian, beginning the Second- 

 ary, or Mesozoic, with the New Red Sandstone or the 

 Triassic period. There is a good review of this work by 

 D. D. Owen (1807-1860) in the Journal for 1847 (3, 153). 



Owen, though accepting the Permian system, is not 

 satisfied with its reference to the Paleozoic, and he sets 

 the matter forth in the Journal (3, 365, 1847). He 

 doubts "the propriety of a classification which throws 

 the Permian and Carboniferous systems into the Paleo- 

 zoic period. " This is mainly because there is no " evi- 

 dence of disturbance or unconformability" between the 

 Permian and Triassic systems. Rather "there is so 

 complete a blending of adjacent strata" that it is only 



