Green Leaf Innovations Inc (GRLF)

[ENZO57]

http://www.westernmininghistory.com/articles/7099/page4/

b. Hand-dug excavations: Hand-dug excavations in the form of pits, trenches or small shafts are generally suited to dry, shallow ground. They are most effectively used to depths of about 7 feet which is the depth from which material can readily be thrown with a shovel. Where practicable, they may provide the best means for sampling a placer. They generally do not require such close supervision as drilling nor do they require the high cost, specialized equipment or highly trained personnel needed for placer drilling. An extra bonus is offered by hand-dug excavations in cases where they remain open for some time, permitting resampling at a later date. In the case of dredge prospects, the principal point in favor of pits or shafts, where applicable, is the fact that they provide a much better idea of boulder content and gravel sizes than do small-diameter drill holes. Boulders are always an important factor in dredging operations.

The simple equipment needed for hand-dug sample pits or shafts is a particular advantage in remote areas or where only a limited amount of sampling is anticipated. A few strategically located pits or shafts may show that the ground is entirely unfit for mining or that it will not warrant the expense of drilling. On the other hand, if they return good prospects and the ground is subsequently drilled, the expense of preliminary hand work will be but a small part of the overall cost. Successful mining companies learned long ago to approach placer prospects cautiously and to make a few diagnostic tests before putting their money in an expensive sampling program. In many cases hand-dug excavations adapt well to this need.