The Falls

Title: Formation of the Mesabi Range
Type: Book
Date: 1894
Source: Orson C. Gillett

Description: Mr. Gillett wrote this description of the geological processes that formed the Mesaba Iron Range.

Transcription:

Chapter II

God Builds the Marvelous Mesaba

There are about two billion people in the world but less than ten million of them know there is such a thing as the Mesaba Iron Range. Yet of all the blessings the Almighty has bestowed Given. The author is suggesting that the Mesabi was given as a gift to the people of the state from God. upon mankind the Mesaba is one of the greatest. He began getting ready for this marvelous blessing about three billion years ago. First of all He probably placed a granite crust here. We call this an igneous* rock Rock that forms when hot, melted rock (magma) deep inside the earth cools and hardens, a process that takes many thousands of years. Igneous means "made by fire." formed by the cooling of molten Something that is melted by heat or fused together by heat. minerals. Today we find greenstones An altered dark green rock such as diorite. and schists A crystalline rock that can be split easily. which are changed forms of the earliest igneous rocks. Probably this region was submerged Covered with water. The author suggests that the area was under water during its past. beneath the ancient sea. During the first billion years of its life some sedimentary rocks Rock formed when layers of sediment (fragments from stone, shells, or plants) build up, and the weight of the upper layers squeezes the lower layers, causing them to stick together as solid rock. Limestone and shale are examples of sedimentary rocks. may have been formed but we are not very certain about this. However, I have picked up some of these ancient schists along the pavement between Gilbert and Virginia, two or three miles north of Eveleth. Another iron range city east of Hibbing. There they stand on end sticking out of the surrounding earth with all of the majesty of their two billion years of hoary antiquity. Literally, whitened (as with age) ancientness. The rocks he is describing are ancient. The are neat and clean in spite of all they have gone through. They must have been tilted through an angle of ninety degrees for the cleavage The splitting of the rock. is practically perpendicular. The rocks are split at right angles. The cleavage is clear cut and gives them their name as a schist is something divided into clearly marked leaves or scales. As they stand they look to be black but closer examination shows them to be a dark green. I thought they were Virginia slate, but Mr. Robinson, chief engineer for the Oliver Iron Mining Company in our district, tells me I was wrong again. they are among our most ancient rocks and are more than a billion years older than the Virginia slates. Now, when I gaze upon them, knowing what they are, I stand in awe and wonderment. Perhaps they were once beneath 15,000 feet of younger rocks which pressed their enormous weight upon them. They have been heated to 500 degrees or more Fahrenheit by the intrusion of hot igneous rocks. They have been twisted and tilted by the movements of the earth. They existed when there was no life upon this planet. They have been far beneath the ancient seas and now the are right upon the surface beside this modern concrete highway No. 35 where hundreds of busy people pass them every day without giving them a single thought. Yet they are part of the foundation upon which stands all of this mighty Giants Range. Mesaba means Giants in the Chippewa language. The old Chippewa medicine men and soothsayers Someone who claims to be able to predict the future. had a legend to the effect that a race of Giants once lived on these hills. Hence, we get this appropriate name for our range-so essential to the welfare and happiness of mankind.