Exploration Drilling
Drilling is employed extensively, either as the principal exploratory method or to supplement exploration by underground and surface workings. Three principal types of drills are employed for this purpose—churn drills, core drills, and hammer drills. In ground too soft to core and in which a churn drill would stick, a rotary drill with a fish-tail […]
Prospecting Lode Gold Deposits
Prospecting for lode deposits begins with a search for mineralized outcrops, the key to the existence of which may often be found in mineralized float (pieces of rock from the lode that have been loosened by weathering and washed downhill). Geologists now generally agree that most valuable mineral deposits have a magmatic origin and, therefore, […]
Prospecting Placer Gold Deposits
Prospecting for placer gold, except perhaps in the case of buried placers, is the simplest form of prospecting. Gold, platinum, and tin are the principal metallic minerals won from placers, but gold (alloyed with varying percentages of silver) is the only metal that has been recovered in commercially important quantities from placers in the United […]
How to Save Hole Sludge in Diamond Drilling
Set the standard sludge box just below the floor of the shanty and in such position that there is room to siphon off the water and take out the sample without moving the box. Connect a tee to the top of the standpipe or casing and lead a pipe from it to the nearer end […]
How to Survey & Sample Diamond Drill Holes
Here is a paper on surveying and sampling diamond-drill holes. The present paper gives a more thorough description of these methods, together with a few changes and notes suggested by further experience. Since, the methods, used constantly by the Cleveland-Cliffs Iron Co., have been developed to a higher degree of efficiency, and have given great […]
Ammolite
Ammonite is an iridescent gem formed within an ancient marine fossil for which it was named—ammonite. Originally discovered by the Blackfoot Indians, ammolite is mined only in Southern Alberta, Canada. Most ammolite is assembled into doublets or triplets to increase durability because solid ammolite is usually thin and fragile, If it’s untreated and solid, ammolite is usually priced per […]
Portable Fire Assaying Furnace
For years past I have traveled in quest of promising mining- properties, over almost impassable mountain-trails to remote places in the mining-regions, usually many miles from an assay-office. If, upon examination, the formation and the ore-deposit appeared favorable, a quick determination of the value of my samples was necessary, in order that I might take […]
Graphic Method of Computing Mine Values
Those who have had occasion to sample a mine not infrequently find that it is impossible to take their sample cuts at regular distances apart, owing to the ground being close timbered, a stope having been taken out, or some other cause. When such is the case a tedious calculation becomes necessary in order to […]
Granitic Magma Crystallization
In discussing the crystallization of a granitic magma it is sometimes assumed that there is a simple pro rata increase of the water content of the residual liquid as crystallization proceeds; i.e., it is assumed that, when the proportion of crystals amounts to one-half, the amount of water in the liquid is doubled, and when […]
Vanadium Deposits
The scope of this paper is the description of two districts in Peru in which vanadium deposits have been found, and the consideration of much laboratory-work that I and others have done to determine the nature of these deposits. It is with regret that I present some of the data in a state of evident incompletion, […]