24 C. R. VAN HISE THE PROBLEM OP THE PRE-CAMBRIAN 



Classification of the pre- Cambrian Rocks of eastern Fenno-Scandia 



Names of tlie sul^divisions. 



Supercrustal rocks. 



Infracrustal rocks. 



.Totnian 



Diabases, sandstones, lab- 

 radorites, conglomerates. 



Rapakivi-granites. 







Unconf or m ability . 





Jatulian . . - 



Upper Jatulian 

 (Onegian). 



Lower Jatulian. . 



Augite-porph y r i e s and 

 their tufiFs, ' ' metaba- 

 sites," anthracite, dolo- 

 mites, slates, sandstones. 







" Metabasites," dolomites, 

 quartzites and quartzitic 

 sandstones, conglomer- 

 ates. 







Unconformability. 



Post-Kalevian gran- 

 ites, injecting the 





Upper Kalevian.. 

 Lower Kalevian. . 



"Metabasites," quartzites, 

 conglomerates. 



Kalevian and older 

 rocks, thus forming 

 "veined gneisses." 



Kalevian.. - 



Unconformability. 







"Metabasites," talc- and 

 chlrorite-schists, d o 1 o - 

 mites, phyllites, quartz- 

 ites, and quartzitic schists 

 (often glassy), conglom- 

 erates. 







Unconformability. 



Post-Bottnian gran- 

 ites, injecting the 



Bottnian 



Uralite-porphyries and 

 their tuffs, jjlagioclase- 

 porphyrites, conglomer- 

 ates, phyllites, leptites, 

 etcetera. 



Bottnian and older 

 rocks, thus forming 

 "veined gneisses." 







Unconformability. 



Post-Ladogian gran- 

 ites, diorites, am- 



Ladogian 



Phyllites and mica-schists, 

 glassy quartzites, con- 

 glomerates (?), "metab- 

 asites," dolomitic lime- 

 stones, hiilleflintas, et- 

 cetera. 



phibolites, etcetera, 

 injecting the Lado- 

 gian and older 

 rocks, thus forming 

 "veined gneisses." 





Katarchaear 



1 



Granitic gneisses, "metabasites," etcetera. 







