19"] STEVEXSOX— FORMATION OF COAL BEDS. 25 



posited them on the bottom of the estuaries, or that vast heaps of 

 organic matter were carried as floating masses to the sea. The 

 Northumberland deposits, large tracts of Scotland, as well as the 

 Donetz field in Russia offer fine proofs of these conditions. There 

 were at least two modes in which coal measures were formed, one 

 terrestrial, the other subaqueous. 



Goeppert^^ in his elaborate work on the formation of coal beds 

 gave the results of many years of study in the Silesian coal fields. 

 A large part of the volume is devoted to determination of the 

 materials forming coal ; it will be considered in another connection. 

 The chapter on the formation of coal beds is supplemented by a 

 mass of illustrations drawn from the coal fields of Silesia, the whole 

 discussion being so compact, so free from unnecessary detail that 

 to make a just synopsis is difficult. The standpoint in Goeppert's 

 w'ork differs much from that in the discussion by Rogers, the only 

 preceding study with which it can be compared. Rogers knew 

 little about the intimate structure of coal itself and reasoned wholly 

 from stratigraphical conditions ; Goepert was a skilfull palseobotanist 

 as well as stratigrapher. 



The important question for Goeppert is, were the coal beds 

 formed of plants growing in place or of plants brought in from 

 other localities. 



There were many islands, mountains, valleys, rivers, etc., in the 

 Coal Measures time. The organic matter was deposited on plains 

 which were covered w-ith sand, clay or mud. The extent of the 

 deposits, their occurrence as plains or as basins show that they 

 were laid down on the sea-bed, on slowly changing coasts or in 

 enclosed sea or lake basins. The few marine products found in 

 coal beds do not favor the opinion that the coal- forming material 

 was collected from distant places and deposited in the depths of 

 bays ; everything indicates the utmost quiet ; the vegetation covered 



^■^ H. R. Goeppert. " Abhandlung eingesandt als Antwort auf die Preis- 

 frage — ' Man suche diirch genaue Untersuchungen darzuthun, ob die Stein- 

 kohlenlager aus Pflanzen entstanden sein, welche an den Stellen, wo jene 

 gefunden werden, wachsen ; oder ob diese Pflanzen an anderen Orten lebten, 

 und nach den Stellen, wo sich die Steinkohlenlager befinden, hingefiihrt 

 wurden?" Amsterdam, 1848, pp. 119-131, 136-139, 141-160, 278, 279. 



25 



