Two revisions were made to increase the content of coalfield geology, mine geology and hydrogeological maps, and was officially promulgated by the Ministry of Energy in July 1989 with the “Geological Survey of Coal Minesâ€. In 1991, the former China Tonglian Coal Mine Corporation formulated the “Regulations on the Management of Coal Mine Geological Survey Mapsâ€, which was implemented in conjunction with the Supplementary Provisions on the Implementation of Coal Mine Geological Survey Legends. The legend symbols commonly used in mine maps are shown in Table 1-1. Table 1-1 common mine map symbol table   Accessories Mask Machine Accessories,Mask Machine Welding Part,Welding Roller,Ultrasonic Welding Teeth Dongguan Pailade Machinery Equipment Co.,Ltd , https://www.pailade.com
In order to facilitate drawing and reading, the mine map must use uniform colors, symbols, descriptions and annotations to represent the objects of the mine map, called the legend. In 1977 and 1987, the former Ministry of Coal Industry has awarded the 1955 "Mine Surveying map legend."
November 10, 2021