Loaming is a form of gold prospecting. it is preliminary to such prospecting as cutting experimental trenches or sinking trial shafts or drilling. Loaming consists in washing surface prospects from the bases and slopes of the ranges until specks of gold or specimens are found to be obtainable with tolerable frequency within certain limits. The gold prospector then proceeds to trace the gold up to hill to its source narrowing the limits of his work as by patient search to approach the vein where the gold has been derived. When the gold prospector can obtain surface prospects of gold up to a certain point or line, but not further, it is necessary to make some trenches to search for the gold vein.
The prospector has often to work along a steep scrubby mountain side selecting the potential gold zones and placing samples in a loam bag. When a gold prospect is discovered, it is necessary to go back to the spots where the samples were taken. Sometimes, there is no indication of a vein, soil and bushes and debris covering its out crop, but by loaming the prospector ascertain its position, so as to expose it by trench not many feet in length. It is important to indicate that an ingenious way in which a valuable and long sought for vein was at lat discovered. Gold prospectors had long found very rich float at the base of a hill whose surface was so deeply covered with loose debris that no trace of the vein could be found.
A prospector found a small lake at the top of the hill and conceived the idea of cutting a trench from this body of water to the edge of the hill, and by damming up the trench, and then suddenly letting out the water to full force, it was cut a deep trench through the loose debris down to bed rock and the gold vein discovered. This prospecting technique is called booming. By this prospecting technique is possible to study the cleavage of quartz and detect if it is free, sharp and defined gold-bearing quartz. A soft, fatty clay or gouge often flanks the vein in zone gold areas. The mountain spurs must first receive attention for veins. If the quartz is hard, it stands up, if soft, it will leave a streak like depression. On finding such, the prospector must first wash out some of the decaying rock. If only a trace of gold is found in the quartz, there is probably a gold vein and some trenches should be dug and exploration systematically followed up. Gold is generally near one wall of a vein, seldom all through the stone. Quartz gold is found in shoots with remaining specimens.
Placers are richer in their richer parts than the veins from which their gold was derived. When shallow placers are due to the wearing down of quartz veins, no placer will be found above these veins or above the point where the vein crosses the placer. Gold may be detected below silver deposits. In this case, the silver vein rapidly disappears and leaves the gold in the deposit. Sometimes, more gold is obtained from leader veins that had been overlooked, than from the main worked vein.