Abstract:The Neogene basin in question is an intermountainous basin with a Hercynian-Yenshan granitic body as its basement. Its overlying strata are made up of the lower zu (N1) and upper zu (N2) of coal-bearrng clastic rocks of Neogene period, the lowest part of the former zu acting as the main ore-bearing bed. Germanium ore bodies mostly occur within the coal seam as stratiform or stratoid layers, cropping out 1300-1700 m above sea level and hidden 0~400 m beneath the surface. They are present primarily in basement paleodepressions, valleys and turns along the margin of the basin close to the basement granite where closed or semiclosed environments are known to have prevailed. Ore bodies correspond rather closely to the coal-seam in thickness and boundaries. Germanium ore is chiefly of germanium-lignite type, having a grade of 0.0n % for a single sample. Germanium occurs in coal mainly in the form of absorbed substance or salts of humic acid whereas uranium is often identified in the coal-seam at the bottom of Nl-2 as absorbed substance, uranyl of humic acid, pitchblende, black uraniferous ore, etc. Germanium ore and uranium ore constitute composite ore bodies with the uranium ore body underlying the germanium ore body. Germanium ore body is large and wide compared with uranium one. It also has relatively stable grade and thickness. The ore deposit apparently possessed several geological conditions favorable for mineralization: l) The basement granite could provide the ore deposit with abundant germanium, 2) the hydro-geochemical conditions ensured the supply of ore material for mineralization; 3) the strata containing organic carbon and coal were positions favoring ore formation; 4) the basement paleotopography determined the location of the ore deposit; and 5) the incoalation of coal-bearing strata at the bottom of Nl controlled the whole process of germanium mineralization. The author holds that this germanium deposit is of sedimentary-diagenetic origrin which has undergone principally two stages of mineralization-sedimen-tation and diagenesis. During the deposition of peat and the formation of lignite, germanium was carried by running water and paleoplants into the basin where it was partly absorbed by organic materials or carbon, some of which formed salts of humic acid.
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白云生.1983.某新第三系盆地含铀的锗矿床的成矿特征及其成因探讨[J].矿床地质,2(1):58~65.1983.Metallogeny and mineralization characteristics of a uraniferous germanium deposit in a certain Neogene basin[J].Mineral Deposits2(1):58~65
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