| 陕西商丹北部锑矿床成因的初步认识 |
| 点此下载全文 |
| 引用本文：.1984.A Preliminary Discussion On The Genesis Of Antimony Deposits In Northern Shangxian-Danfeng Area[J].Mineral Deposits,3(4):45~52 |
| Hits: 2293 |
| Download times: 1652 |
|
| |
| A Preliminary Discussion On The Genesis Of Antimony Deposits In Northern Shangxian-Danfeng Area |
|
|
| Abstract:The antimony deposits in northern part of Shangxian-Danfeng area refer mainly to the Gaolinggou antimony deposit at northern Shangxian and the Caiwa antimony deposit at northern Danfeng. These two deposits extend discontinuously in EW direction forming an ore belt with a length of 20 km, and in the main have identical geologic setting and characteristics. The antimony ore belt is situated at the south margin of the east sector of north subbelt of the Qinling latitudinal belt. The strata in this region are mainly of pre-Ordovician sequence, consisting of marble, biotite- plagioclase gneiss, crystalline schist, granulite, migmatite and so on. Structure seems rather complicated, the ore belt is distributed on the south of the Gaolinggou-Shuang-huishu deep-seated fracture and on the north limb of the Jieling anticlinorium with ore deposits controlled invariably by second-order faults and folds as well as by interformational exfoliations, fragmental zones, and cracks. Rather than being confined to certain horizons or lithological characters, the antimony deposits occur in strata of different ages, such as Late Proterozoic, pre-Ordovician and Mesozoic, which are made up of marble, sands tone. gneiss, schist, granulite, migmatite, granite, etc. Silicification must have had an intimate bearing on antimony abundance and occurrence of antimony orebodies. For example, pre-Ordovician sequence (consisting of marble, gneiss, migmatite, etc.) on north limb of Jieling anticlinorium whicb has suffered various degrees of silicification, ubquitously has antimony abundances several hundred times higher than its Clark value; furthermore, antimony orebodies are seen occurring in structural space of this sequence. On the contrary, strata on south limb of Jieling ajiticlinorium which are of the same age and lithological characteristics with those on the north limb but have suffered no silicification, contain little antimony and in the main have no antimony mineralization. Sulfur isotopic data of this area show that δS34 values vary in the range of -7.2 ~ +8‰ and average S32/S34 is 22.099, suggesting that, instead of being sedimentary origin or coming from mantle-derived magma, sulfur in antimony sulfides seems likely derived from granites of crustal remelting type. The Mangling granitic mass, located some 12 km north of the ore area, is characterized by Na2O>K2O, raletively low Fe3+/Fe2+, Al-oversaturation, some secondary minerals such as limonite, chlorite and epidote in inner core of the accessory mineral zircon, and no corresponding volcanic rocks, thus belonging probably to crustal remelting type. Regional metallogenic cbaracteristics imply that there exist metallogenic series of high-middle-low temperature hydrothermal ore deposits around the Mangling granite mass. Based on all these data, the author bolds the opinion that antimony ore deposits in this area should be low temperature hydrothermal deposits genetically related to the Mangling granite mass. |
| View Full Text View/Add Comment Download reader |
|
|
|
