File:Preliminary report on the geology of east central Minnesota including the Cuyuna iron-ore district (1918) (14764231565).jpg

Identifier: preliminaryrepor00hard (find matches)
Title: Preliminary report on the geology of east central Minnesota including the Cuyuna iron-ore district
Year: 1918 (1910s)
Authors: Harder, Edmund Cecil, 1882- Johnston, A. Walfred, author Geological Survey (U.S.)
Subjects: Geology Iron mines and mining
Publisher: Minneapolis, University of Minnesota
Contributing Library: Wellesley College Library
Digitizing Sponsor: Boston Library Consortium Member Libraries

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Text Appearing Before Image:
A. GRANITE AND MICA SCHIST OUTCROPS AT LOWER FALLS OX SNAKE RIVER, KANABEC COUNTY
Text Appearing After Image:
B. GRANITE EXPOSURES AT UPPER FALLS ON SNAKE RIVER, KANABEC COUNTY ROCKS OF EAST CENTRAL MINNESOTA 45 dikes consisting of quartz and pink feldspar with abundant muscovite.The association shows that the granite is intrusive into the schist, themasses of the latter being fragments caught in the granite. If the schistis of upper Huronian age, as is generally supposed, then the granite ispost-upper Huronian and may be equivalent to certain other Keweenawangranitic rocks of the Lake Superior region. Because of the isolatedsituation of these rocks, however, correlation is difficult, and the agerelationships are therefore uncertain. The rock exposures along Hay Creek and along Snake River nearUpper Falls, are in general similar to those at Lower Falls in that theyconsist largely of medium-grained gray and pink granite. There is morepegmatitic rock, however, in these exposures and locally also the graniteis quite fine-grained in texture. Pegmatite is especially abundant atUpper Falls and alon

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