224 B. H. SoiDorth—A Great Pod- Glacial Flood. 



VI. — Traces of a Great Post-Glacial Flood. 



11. Evidence of the Loams and Brick-earths. 



By H. H. HowoRTH, F.S.A. 



THE best test of the difficulty of an inquiry is the number of 

 theories which its solution has evolved. If we test the subject- 

 matter of the present communication in this way, we shall be assured 

 that, second only perhaps to the Loess, which has occupied us pre- 

 viously, it may claim pre-eminence for the difficulty of the problems 

 which surround it. We only venture upon a tentative solution. 

 Such a solution is in effect the only one which is available in 

 science at all ; for to-morrow's fiercer light is certain to throw out of 

 perspective some of to-day's most cherished convictions ; and finality 

 is outside the pale of all living and fertile inquiry. 



In our examination of the Loess we saw reason to conclude 

 that it is very largely an accidental feature in surface geology. 

 That so far as we can make out, it is largely due to the outpouring 

 of quantities of volcanic mud, which swept over and mingled with 

 the disintegrated beds which previously occupied the same area, at 

 the time when the great cataclysm occurred, which forms such a 

 clear barrier between Palgeolithic man and his companions and those 

 who came after. 



If we therefore eliminate this accidental and transitory feature 

 from our view, and realize the state of things before the Loess was 

 poured out, we shall find, as we believe, that Europe, north of the 

 Balkans and the Alps, may be divided into two well-marked zones : 

 the northern one characterized by surface deposits consisting of 

 Drift and the various boulder formations ; and the southern by the 

 absence of these boulder formations, and the presence of a great 

 mantle of loain with associated gravels and sands. This loam is 

 not found in Northern Europe, and marks a belt or zone which was 

 once, as I believe, continuous from the Volga to the Atlantic. It 

 occupies a large area in Southern Russia south of the Chernozem, and 

 is known to the Eussian geologists, as the same deposit is known to 

 the French, as Diluvium. Mr. Belt tells us that in 1875, while 

 detained at Wolochisk, in the province of Volhynia, near the Eussian 

 frontier, he found in the clay that had been thrown out of a well 

 shells of Succinea ohlonga and Pupa muscorum, which are very 

 characteristic shells of the French loamy deposits. This clay caps 

 the high plateau which forms the steppes of Southern Eussia, and 

 may, he says, be traced for hundreds of miles. He further adds, 

 " On my return from a visit to Southern Eussia during the present 

 year (i.e. 1876), I determined to examine this clay, which is 'the 

 Diluvium ' of the Eussian geologists, nearer to the mountains, and 

 for that purpose stayed twelve hours at Pod wolochisk in Galicia. I 

 was greatly gratified by finding Loess shells {i.e. the very shells that 

 are found in the French Diluvium) in abundance." — Quarterly 

 Journal of Science, vol. xiv. jip. 74-5. 



The areas occupied by Diluvium in Southern Eussia and in France 

 are now separated by the Loess. Before the outpouring of the latter, 



