476 EDWARD STEIDTMANN 



Huronian 



Conglomerate 



Arkose 



Graywacke 



Conglomerate 



Unconformity 

 Laurentian 



Granite, gneiss, pegmatite, aplite 



Igneous contact 

 Keewatin 



Quartz-porphyry and porphyrite 



Rusty weathering carbonate rock 



Phyllite, slate, and graywacke 



Greenstone and green schist 



