350 J. BARRELL FLUVIATILE ORIGIN OF OLD RED SANDSTONE 



ditions, and under conditions of climate which, though doubtless varying 

 much from time to time, were yet, on the whole, characterized by an annual 

 rainfall decidedly below the average in amount. It is this feature which has 

 imparted a common character to the whole of this series of rocks." 



"The fauna of the Upper Old Red consists almost exclusively of fishes which 

 probably found their way into the sediments from the rivers of upland origin, 

 whose waters were dissipated by the excessive evaporation when they reached 

 the lowland area." 



"As regards the mode of origin of the Old Red of the Caledonian area 

 (Lower Old Red), there appears to be evidence of a satisfactory nature that 

 the whole of this vast formation was accumulated under continental condi- 

 tions, partly in large inland lakes, partly as torrential deposits of various 

 kinds, partly as old desert sands, and partly as the result of extensive volcanic 

 action." 6 



With these views the present writer is in accord, except that he would 

 give first place to true fluviatile deposition, spreading sediments on broad 

 and flat river plains, a form of deposition intermediate between torrential 

 and lacustrine and yet quite distinct from either. It is one which is not, 

 however, specifically mentioned by Good child. 



In 1907 the writer, unaware at the time of Goodchild's paper, presented 

 the evidence showing the wide-spread development of floodplain deposits 

 in the Old Eed Sandstone and the presence of a fluviatile piscine fauna. 

 This view was, however, only published at the time in brief abstract. 7 



In 1908 Walther published a volume entitled "Geschichte der Erde und 

 des Lebens." In this is a chapter on the Devonian continent which lay 

 northwestward from central Europe and which included Scandinavia and 

 the British Isles. He includes in this same continent Greenland and the 

 Canadian Shield- The name he gives to it is "The Old Eed Northland." 

 The chapter, pages 254 to 271, is largely of general statements and draws 

 an analogy between the climatic and sedimentary conditions of this con- 

 tinent and the present interior of Asia and Australia. Walther states, for 

 example (page 259) : 



"The northern Devonian land consisted of many parts. Many lines of frac- 

 ture passed through the older mountain structures. Some of the principal 

 lines extending northeast are yet visible. Often the sandstones lie on the 

 steep-walled cores of the ancient mountains, filling up deep basins, so that 

 great regions of deposition, as the 'lakes' of Orcadie, Caledonia, and Lome, can 

 be distinguished. One should not conceive under that term, however, enduring 

 bodies of water, but rather wide basins surrounded by mountains limited by 

 temporary sheets of water, water which converged to shallow lakes of variable 



6 J. G. Goodchild : The older Deutozoic rocks of North Britain. Geol. Mag., Decade 5, 

 vol. i, 1904, pp. 591-602. 



7 F. B. Loomis : The American Society of Vertebrate Paleontology. Science, vol. xxvii, 

 Feb., 1908, p. 254. 



