REPORT OF THE DIRECTOR IQIO IO5 



minds a profound impression of similarity and resemblance, so 

 much so, that while in the field the Americans in the end became 

 embarrassed at their constant and almost irrepressible tendency to 

 remark upon it to their Swedish hosts. The visitors were fearful 

 lest they prove wearisome. 



In conclusion the writer may express his indebtedness to Pro- 

 fessors Hogbom, Holmquist and Backstrom and to Doctors Quensel 

 and Gavelin for the personal guidance and explanations which made 

 the excursions so exceptionally instructive. 



As an appendix to the remarks on Swedish geology, a brief state- 

 ment of the scheme of classification adopted by Professor Seder- 

 holm in Finland may be given. As will appear, the older rocks 

 have been more extensively subdivided in Finland than in Sweden. 

 The American equivalents suggested by Professor Sederholm are 

 added. 



Jotnian Diabases, labradorites and elastics, 



rapakivi granites Keweenawan 



Unconformity 



Upper Eruptives, elastics, anthracite, dolo- 



Jatidian mite 



Lower Greenstones, elastics, dolomites 



Unconformity. Post-Kalevian gran- 

 ites 



Upper Huronian 



Upper Greenstones, elastics 



Kalevian Unconformity Lower Huronian 



Lower Greenstones, schists, elastics, dolo- 



mites 



Unconformity. Post-Bottnian gran- 

 ites 



Bottnian Eruptives, elastics, leptites 



L^'nconformity. Post-Ladogian gran- 

 ites 



Ladogian Greenstones, phylhtes, schists, elas- 



tics, limestones, halleflintes 



Katarchean Granitic gneisses, greenstones etc. 



In the above table I have condensed the rock types under collective 

 names, like elastics, and have called by the name greenstone, rocks 

 described by Professor Sederholm as metabasites. The full table, 

 printed in English, will be found on page 93, Bulletin 23, of the Geo- 

 logical Commission of Finland, 1907. 



