Gold miners , Aug 14, 18:09
The obvious first question of any gold miner is where to find gold. Gold is found throughout much of the earth. Historically, the highest concentrations of gold have been found in primary and secondary deposits. Primary deposits are known as lode ore where gold is originally deposited. In lode ore, gold is found in veins, nuggets and bits. This is embedded in lodes or veins in rock, often together with quartz, silver, copper, platinum and iron pyrite (fool’s gold). Where to Find Placer Gold - Secondary Deposits Gold can also be found in the form of free flakes, grains or larger nuggets that have been eroded from the primary deposits and end up in alluvial deposits called placer deposits. Over the years water erodes the exposed lode outcrops and that gold ends up in streams, rivers small creeks, and river beds where it collects. Gold is heavier than most minerals and so it flows with fast moving water and tends to sink and be found in areas where the current slows and is no longer powerful enough to carry the gold. Capped, culverted Mine Shaft While gold can be found in placer deposits, and there are many articles on the subject we will focus our attention on extracting gold from the primary deposit. Lode mining is a better place to focus time and energy. That is because the amount of gold that can be extracted from the primary source compared to the secondary source is on average ten to one. Ten times the amount of gold can be extracted per day’s work at a mining claim than can be found in a day of placer mining. Which makes sense when you consider that placer mining is just finding the gold flecks that were soft enough to erode from the primary deposit and wash downstream. The largest mining companies in the world are not focused on chasing nuggets that settled in a riverbed. They are going after the vein, the source of the metal. To further the point, in the old days miners would work their way up streams looking for gold specs in attempt to find the primary source of the gold, following the trail of evidence to the source. Placer claims do have their place and they do have certain advantages. Plenty of information can be found online about placer gold. This article however will focus on finding gold in the primary deposits. Where to Find Gold in Lode Mines - Primary Deposits So where are the primary deposits? The primary deposits are often found around faults in the Earth's crust. Two things must occur if order for a large ore deposit to form. Obviously the material needs to come from somewhere, so there must be a source, but then there must be a means of transportation and also there must be a trapping, or a location where the gold gets stuck, or deposited. That's why faults or contact zone, where two different bedrocks meet, is often where gold is found. Plate tectonics or the movement of the earth’s crust is the reason gold deposits form. Almost all gold deposits are formed by intrusion deposits. Intrusion Deposits Intrusive gold deposits are generally found in granites and igneous rock such as quartz. Copper is usually present in the rock as well. These minerals were carried in liquid form with the magma or were part of the magma itself and were forced into the rock walls. Lode Ore Deposits Lode ore deposits are generally high-grade, thin veins that are found near faults. They are primarily made up of quartz veins. Lode ore deposits are usually found in basalt or in sediments, although when found in the faults, they may be found in igneous rocks such as granite.