Answers for questions 1 - 8 are indicated on the cross section to the right. Click on the image to get the normal size picture.
9. The ash from volcanoes in eastern North America during the Paleozoic were produced by partial melting of subducted ocean crust. This would have given rise to andesitic-dacitic-rhyolitic lavas (results from the midterm exam). Handout four indicates that these lavas would contain potassium fieldspar (K-fieldspar KAlSi3O8). Therefore if the ash beds in the Paleozoic sedimentary rocks im Minnesota come from eastern North America they should contain K fieldspar.
10. Slate, schist, iron formation, granites and gneisses as illustrated on the cross section.
11. Yes, at the Mid Atlantic Ridge and in the subduction zone beneath Japan. The Eurasian plate is moving west to east.
