Vol. 62, .] THE CKAG OF ICELAND. 715 



evidence of the persistence of the same type of eruptions in later 

 Tertiary time. The occurrence of Glacial deposits between still 

 younger lavas indicated that such eruptions continued during the 

 Ice-Age, while the modern history of Iceland showed that the 

 volcanic activity has persisted up to the present time. Not- 

 withstanding the published writings and the excellent map of 

 Prof. Thoroddsen, and the labours of the Author of the present paper 

 as -well as of other observers, much remained to be made known as 

 to the details of this vastly-protracted volcanic history ; and all 

 interested in this department of geology must indulge the hope that 

 the subject may be more fully illustrated before many years pass 

 away. 



Prof. Sollas remarked that the addition of 500 feet, 1 made to the 

 sedimentary series by the discoveries of the Author, involved an 

 addition of 50,000 years to the age of the earth, as calculated from 

 the thickness of the stratified deposits. 



1 [The thickness of the sedimentary series considerably exceeds 500 feet.^* 

 H. P., August 1906.] 



