Febhuaet 26, 1909] 



SCIENCE 



323 



has augmented the similarity. Huge mo- 

 rainic accumulations south of the Great 

 Lake region of North Amierica form the 

 watershed between the Mississippi and St. 

 Lawrence Rivers, and similar morainie de- 

 posits form the watershed between the 

 Baltic and the Black Seas. Thick loess 

 deposits are found in front of these mo- 

 rainie deposits in the Mississippi basin as 

 well as in the interior of Russia. The loess 

 gives rich harvests to the corn regions of 

 Iowa, Nebraska, Kansas, Missouri and Illi- 

 nois, the counterparts of which are found 

 in Wolhynia and the region of the Tsher- 

 nosiom of the south central governments 

 of Russia. 



East of the Mississippi basin the old 

 Paleozoic strata are folded and form the 

 Appalachian belt, and similarly, west of 

 the plains of Riossia the Paleozoic strata 

 of Europe are folded, forming a set of 

 mountains which we can trace from the 

 south of Russia to the west coast of Europe. 

 In the central part of Germany these 

 mountains constitute the belt of the Ger- 

 man upland, and here it was that their 

 geological history was first Understood. 

 The folding of the strata occurred near the 

 end of the Paleozoic era and ceased before 

 the end of the Permian epoch. Then they 

 were base-leveled and covered totally or in 

 part by Mesozoic deposits, after which 

 mountains arose by faulting and warping, 

 forming here and there true tilted blocks. 

 The elevated parts lost their Mesozoic cov- 

 ering and the folded old strata again be- 

 came visible. 



This history is nearly the same as that of 

 the Appalachian region. Here also the 

 folding of the strata ended towards the 

 close of the Paleozoic era and the folded 

 mountains were leveled down. Then they 

 became partly or totally covered with 

 Mesozoic deposits, and the mountains of 

 to-day were formed by upheaval. In 

 North America, indeed, they form a more 



connected zone, while in Europe they are 

 mostly groups of mountains, separated 

 from each other by basins of Mesozoic or 

 younger strata. During the epoch of fold- 

 ing, the Appalachian region and the zone 

 of the Hercynian Mountains of Europe 

 may have formed mountains of the height 

 of the Alps of to-day. I called them, there- 

 fore, the Paleozoic Alps of middle Ger- 

 many, but to-day these regions have only 

 lower altitudes ; they do not surpass, as the 

 Appalachian region does, 2,000 meters. 

 The striking features of these base-leveled 

 Paleozoic mountains consist of the fact 

 that on both sides of the Atlantic the belt 

 of their ancient foot-hills contains coal 

 measures. As the Allegheny region in 

 North America, so the mountains of South 

 Wales, the northern boundary of the Ar- 

 dennes and of the neighboring Rhenish 

 mountains contain the richest coal meas- 

 ures. And as we find west of the Alle- 

 gheny region some coal measures, so we 

 find some extensive coal layers north of 

 the belt of the Hercynian Mountains in 

 England and Scotland, in upper Siberia, 

 in the east of Germany, and in some places 

 in the interior of Russia. The industrial 

 evolution of eastern United States, of Eng- 

 land and Wales, or Belgium and the Ger- 

 man empire, is based on the same fact, 

 that a rich vegetation once covered the 

 foot-hill region of the mountains up-turned 

 towards the end of the Paleozoic era. 



It is very interesting to see how the 

 Appalachian region ends at Newfoundland, 

 forming the projecting eastern corner of 

 North America, and just opposite in south 

 Ireland, in South Wales, in Cornwall and 

 in Brittany the belt of the old Hercynian 

 Mountains of Europe begins. One seems 

 to be the continuation of the other, and 

 such an excellent geologist as Marcel Ber- 

 trand maintained that we have here to deal 

 with the two ends of one very extensive 

 belt of mountains whicl extended through 



