How to find gold sand
There are many methods for ore prospecting. There are five commonly used methods: 1 natural heavy sand method, 2 engineering heavy sand method, 3 old mining survey, 4 geological landform analysis, 5 geophysical exploration and aviation new technology method.
The first three methods are through sampling survey to find out whether there is gold deposit and directly determine whether or not mineralization is a direct ore prospecting method; the latter two methods mainly through the analysis and evaluation of mineralization conditions, research environment and sediments. Some characteristics, to infer whether it is possible to form ore, is an indirect ore prospecting method, in which geological and geomorphological investigation is the basis of sand gold prospecting analysis. Generally, it is mainly based on geological and geomorphological analysis to determine where to go to find gold deposits and where to place sampling projects. The following are the specific methods for gold prospecting.
1. Natural heavy sand method The natural heavy sand method is based on the fact that the density (weight) of the gold particles is very large, and can be directly selected by using the panning disc. The surface of the loose debris is deposited or not pitted for sampling, in the field. Washing directly determines if there is a method for the presence of gold. Sampling includes heavy sand sampling of river sediments, sampling of outcrop sediments on terraces, and heavy sand sampling of slopes on hillsides.
The first two samples can be used to understand the gold content of water sediments, the approximate distribution of gold, and the grade and thickness of the gold layer in the terrace. The sampling in the residual slope of the hillside is used to trace the source of gold in the small ditch mountain area where sand gold is known. By sampling the shallow pit at a certain interval on the slope and slope foot, the sample is washed and washed according to the gold result. The distribution range narrows the rock gold prospecting target area. Among the three types of sampling, the most widely used method is the river natural heavy sand method.
Sampling of natural heavy sands in rivers is generally carried out from the bottom up along the upstream of the water system or along the small and medium-sized valleys containing gold. The advantages are: the tool is simple (as long as a hoe, a panning tray), the sampling workload is small (digging shallow pit 0.3-0.5m deep, sample weight 20-40kg), simple and easy, one can also do, very quickly It is possible to directly obtain the gold information at the near surface. The disadvantage is: because the sample is taken at a shallow surface, it does not reflect the gold content of the gravel layer in the deep, and the gold is usually concentrated in the lower part of the gravel layer near the bedrock. Therefore, the measurement results of the heavy sand in the near surface are looking for Mines generally have only qualitative significance.
The natural heavy sand sampling effect depends on the choice of sampling points and horizons. In the plane, the sampling points should be placed in places where sand gold is enriched, such as the sudden widening of rivers, the convex bank of rivers, the gravel sedimentary area of ​​riverbed shoals, the intersection of main and tributary, and the rock in the riverbed. Above the beach, above the rock, at the beach or at the heart of the beach, in front of the large obstacles in the water flow, the slope of the river bed is steeped and steeped, “close the mountain, above the river valley or in front of the “Yingmen Mountain†accumulation area. In the vertical section direction, the bottom of the gravel layer near the bedrock is the best. In the glutenite area, it should be taken in the riverbed sediment below the branch valley of the cut glutenite layer. In the mountainous area with multi-level trench net development, Samples should be sampled in the branch valleys. When taking the outcrop samples, they should be taken as far as possible at the bottom of the gravel layer or near the bedrock. Each sample should be 0.2-0.5m long. The sample weight should be at least 20kg or by volume. 0.01m3 (approx. 1 standard ship shape panning plate full disk sand sample). When sampling along the river, the spacing depends on the size of the valley, no mechanical fixation.
The determination of sampling points should be based on the principle of favorable geological and geomorphological conditions. Small trenches of three to five kilometers long can be sampled at roughly 800m intervals, and trenches of about ten kilometers long can be sampled at a distance of 1600m. When taking the slope product sample, the sampling points are arranged according to the parallel hill slope contour line, and the point distance is 80-40m. All sampling layers are taken as far as possible in the gravel layer or in the clay- bearing gravel layer, avoiding the pure clay layer. The old tailings pile should be directly sampled from the near upper surface layer, and the pit depth is 0.3-0.5m. All kinds of heavy sand sampling must calculate the weight or volume of the product to calculate the grade. Samples are sent to the laboratory after being washed in the wild.
2. The engineering heavy sand method is an effective method for drilling loose deposits and systematically sampling using sand drills or exploratory wells to understand the gold content of loose deposits and directly determine the grade of gold-bearing layers. Since the gold and industrial gold deposits mainly exist at the bottom of the loose sedimentary layer, the engineering heavy sand method can find out the deep sand gold enrichment and provide direct prospecting information. The basic point of adopting this method is to have a more adequate basis for the sampling project point and the feasibility of construction. Secondly, no matter what kind of sampling main course is to penetrate the gold-bearing layer and control the depth below the bedrock surface at least 0.2m deep. The use of sampling engineering for sand gold prospecting must be based on the analysis of geological and geomorphic conditions. According to the prospecting signs and clues, the favorable parts are selected in the favorable ore-forming section, and the project is arranged according to the certain engineering network. The favorable part should be determined according to the gold enrichment and metallogenic regularity.
3, sand gold old mining and civilian mining survey Many sand gold areas of the river upstream or branch ditch fine valley are common in the sand gold hand-made old mining tracks, they are effective signs of gold mining. According to the old mining tracks, further exploration of the periphery can often achieve good results. The large-scale artificial tailings in the old mining area are also often industrially valuable ore bodies. In addition, through the civil mining survey, many valuable information about the geological characteristics, regularity and prospecting clues of the sand gold deposits can be obtained. Therefore, the sand gold mining survey has important prospecting significance.
4. Geological and geomorphological survey is the basic method for gold prospecting. It is mainly used for the analysis of gold mineralization conditions and the prediction of favorable ore-forming areas. In the prospecting stage, the main survey is the river valley route. Among them, the geological survey can adopt the natural outcrop method, the river debris observation method, and use the known gold-growing ditch in the area as a control analogy, and at the same time take some natural heavy sand samples to understand the gold content. Indirectly or directly determine whether there is no gold replenishment and the level of wealth. In the investigation, attention should be paid to understanding the tectonic setting of the valley and the geological phenomena associated with gold mineralization.
The geomorphological observation mainly divides various landform units of river valley type and determines its distribution, and understands its scale, genesis, sediment characteristics and gold content, and maps the Quaternary on the 1:50000 or 1:25000 scale topographic map. Geological sketches, drawing the boundary line of the main geomorphic unit, providing reference for the layout of the sampling project and the subsequent delineation of the ore body.
5. Some experiences of folks looking for gold deposits Heilongjiang Province is a major producing area of ​​sand gold in China. It has a long history of mining and has accumulated rich experience in finding sand gold mines.
(1) Determine the prospective section according to the geomorphology and the rule of sand gold enrichment 1. Look at the “three mountains†and “four nosâ€, one is “south mountainâ€, “closed mountainâ€, “yingmen mountainâ€, “not exposed before the ditch†"There is no blockage behind the ditch", "the wind is not exposed in the ditch" and "the whole ditch is not exposed." "The mountain" is the golden mountain in the upper reaches of the river valley. It is tall (not blocked) and "Ma Teshi" ( Quartz ) is mostly characterized. Experience suggests that there is a greater likelihood that a mountain will form a gold deposit in the valley.
"Guanshanmen" is the valley-shaped mountain, also known as "close the door." “Yingmen Mountain†is the mountain facing the river in the corner of the river valley. It is also called “no mouth†and “no mouthâ€. This landform is a favorable sign of gold deposits. In the valley above the "Guanmen Mountain" or in the valley in front of the "Yingmen Mountain", it is a place where sand gold is enriched.
“No wind†is also called “no waistâ€. The mountains on both sides of the river producing sand are higher, and the “wind†seems to be unable to get out. “Unbone†means that the rock on the bottom of the river bed is not exposed, indicating that the valley is in the accumulation stage.
2. "The small ditch is out of the mouth", "the big ditch has legs", "not too big or too small in the belly". The small ditch refers to a small valley with a length of less than 3 km. “Small ditching out†means paying attention to finding gold deposits at the exit of Xiaogou. When the length is above 10 km, it is a large ditch. “The big ditch has legs†means that gold deposits are found in the larger valleys, so it is also possible to find gold deposits in some of the valleys upstream. Conversely, if there is a gold deposit in the valley, there may be a gold deposit in the main valley. It is not too big or small (Zhonggou) with a length of 3-10km, and the main mineralization is in the valley.
3. "Gold out of the shade". According to folk experience in the cold region, alluvial gold deposits, especially terraces, are mostly distributed on the side of the valley. That is, the east-west river valley, there are many gold deposits on the terraces on the south side of the valley, and there are few gold deposits on the north side of the valley. On the north side, there are few rivers and valleys in the north-south direction. The gold deposits are mostly from the west terraces, and the ore deposits on the east side are rare. .
(2) River heavy sand sampling to find gold
Taking heavy sand samples along the river for gold prospecting is one of the most common methods used by the people.
The main experience is: 1. The sampling points should be reasonable and have a certain representativeness. Usually, the sampling line spacing is 200-300m. 2. The sampling position should select the inner part of the river to change the flow direction (turning); the river water flow rate is significantly slower; the front of the large obstacle object in the river bed; the side of the main tributary convergence. 3. Pay attention to the sampling horizon. When mud (clay), sand and gravel are available, it can be taken. 4. When sampling on the old exploration pit or the old tailing sand pile, the topsoil part should be stripped first, but do not dig too large. It is best to find the gravel sample with the bedrock fragments. It is not possible to take the purely washed gravel part. . 5. Can not be used for water in the sample.
Car Parts,Plastic Injection Molding Parts,Custom Injection Plastic Parts,Injection Molding Parts Boat Lever
Ningbo Zongchi Machinery Technology Co., LTD , https://www.nbzcdiecastservice.com