Prospecting

Title: Description of the Prospecting Process
Type: Book
Date: 1897
Source: Minnesota Historical Society

Description: This page from a book by Edmund Longyear describes prospecting for iron ore.

Transcription:

Explorations on the Mesabi Range.

BY E.J. LONGYEAR, HIBBING, MINN.

(Lake Superior Meeting, July, 1897.)

THE rapid development of the Mesabi range has been a matter of much wonder to those familiar with ore-deposits Valuable minerals. elsewhere, and much skepticism was shown when "millions of tons of ore on the Mesabi" was first reported. Now, however, with over 8,000,000 tons to its credit at the close of 1896, prospect of 3,000,000 more this year, and more ore "in sight" than ever before, it is evident that the first claims for the range were not so greatly exaggerated as perhaps even those who made them thought they were at that time. An explanation of the ease with which these deposits have been explored is found in their mode of occurrence. Lying in flat beds and near the surface, and only exceptionally occurring under a taconyte "capping," Layer of rock. and prospector had only to sink a few vertical test-pits on a forty-acre tract down to the rock to be reasonably sure whether his property contained ore or not. If he found ore in one or more of these preliminary pits, Tests to find valuable ore. he would then fill in with more pits until the ore-area was entirely outlined by test-pits form 200 to 400 feet apart. In the early days of the range the testing was almost entirely done by digging pits with pick and shovel. When water was encountered, work had to be stopped unless a steam pumping-plant Steam-powered pump. was put in, resulting in greatly-increased expenses. Latterly, drills have been used with great success in continuing the exploration after water has been struck in the pit, rendering further progress with pick and shovel impracticable.