38 GEOLOGY OF OHIO. 



stoniness of the surface and margin of the northern drift of the British 

 Islands can, of course, only with propriety, be given by those who have 

 studied the phenomena on the spot, but we may offor the conjecture that 

 the clay has been most thoroughly washed out of these portions. 



THE FOREST BED. 



The above name was given in our second volume to a sheet of soil 

 with fallen, and sometimes standing tree trunks, beds of peat, etc., 

 which, in Southern Ohio, rests upon the Erie or Bowlder clay ; and it was 

 shown to be the product of a growth of vegetation which, after the re- 

 treat of the glacier, covered much of the nearly continuous, but, un- 

 even sheet of morainic material left behind it. This was for ages a land 

 surface which sustained a forest of arborescent and herbaceous plants, 

 the home of the mammoth, mastodon, giant beaver, and doubtless, many 

 other animals. Numerous instances of the occurrence of vegetable mat- 

 ter in the Drift of other portions of the Mississippi Valley were cited in 

 connection with the description of the Ohio Forest bed ; but it was not 

 asserted, nor can it now be, that these were continuous or synchronous 

 with it. The facts reported proved conclusively that the southern half 

 of the State was covered with an inter-glacial forest, the first indicatiou 

 found on this continent of an interval of mild climate in the ice period. 



The remarkable facts reported by Mr. George Jennings Hinde, of 

 Toronto, in his very interesting paper, " On the Inter-Glacial Strata of 

 Scarhoro Heights,"* are not only confirmatory of the views advanced in 

 our first volume, but seem to indicate a second inter-glacial mild period ; 

 inasmuch as he finds three beds of Till or Bowlder clay, with stratified 

 and fossiliferous sands and clays between them. 



Professors CroU and Geikie, in their "Climate and Time," and "Great 

 Ice Age," present what seem to be conclusive proofs of one or more 

 inter-glacial, warm, or less cold intervals in Europe during the ic 

 period, and they are generally accepted as such by geologists. These 

 changes may have been in part local, but the evidence that the ic 

 period of Europe was synchronous with that in North America, is very 

 strong, and it is now generally believed that the causes which produced 

 the excessive cold, aSected the whole northern hemisphere. Our Forest 

 bed is confirmatory of this theory — as any great changes of temperature 

 recorded in the European superficial deposits should also be indicated 

 here, and it constitutes another marked correspondence between the au- 

 tographic records of the Ice Age in the old and new worlds. Further 

 investigation will be required, both here and abroad, before it can be de 

 termined whether the parallelism is exact. The subject is one of great 



* Canadian Journal, April, 1677. 



