【作者】 郑建民；

【导师】 毛景文；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2007， 博士

【摘要】 冀南邯邢地区位于华北地台中部,是我国重要的夕卡岩型铁矿矿集区,目前已发现不同规模的矿床100多处。矿体形态复杂,大小不一,主要赋存于中生代中性侵入体与中奥陶统碳酸盐岩接触带及附近。褶皱是重要的控矿构造。矿石类型单一,主要矿物成分为磁铁矿。矿化蚀变具明显的分带现象。分析了与本区夕卡岩型铁矿有关的两套中酸性侵入岩的就位机制特征及与成矿关系。认为符山杂岩体属被动就位机制,岩体内部形成呈捕虏体状赋存的铁矿体,远离接触带的深部仍具找矿潜力;武安杂岩体属主动就位机制,岩体内部捕虏体罕见,相应的铁矿床主要产于岩体与围岩接触带处,少量形成于碳酸盐岩围岩中;主动就位机制下形成的褶皱是重要的容矿构造。在该地区新发现熔融包裹体和熔-流包裹体,对其相态特征、均一温度、盐度等进行了观察测试,并对其成因进行了探讨,认为这两种类型的包裹体是由早期接触交代成因夕卡岩重新熔融形成的。早期蚀变阶段夕卡岩矿物的δ18OV-SMOW值为5.3～8.5‰,矿物包裹体δ13CV -PDB值为-2～-11.2‰,δDV-SMOW为-80～-109‰,相应的δ18OH2O值为0.84～8.62‰;矿石矿物磁铁矿的δ18OV-SMOW值为3.7～5.1‰,包裹体δ13CV -PDB值为-5.6～-24.9‰,δDV-SMOW为-79～-156‰,相应的δ18OH2O值为10.61～11.41‰。表明成矿流体主要来源于地幔,但有少量地壳物质的混入。矿区夕卡岩铁矿中黄铁矿δ34S=11.6‰～18.7‰,介于岩浆硫与沉积膏盐硫之间,表明成矿过程中特别是成矿晚期热液活动中汲取了大气水及石膏层中的部分34S。对西石门铁矿矿石中与磁铁矿共生的金云母进行40Ar-39Ar同位素测年,首次获得该地区与矿化直接有关的精确测年资料。结果表明,样品的坪年龄为133.1±1.3Ma,相对应的等时线年龄为133.6±2.5Ma,表明该区大规模成矿作用形成于早白垩世。与铁矿矿有关的岩体往往是多期脉动形成的,早期侵入体在钠长石化过程中提供成矿物质;后期侵入体带来的岩浆热液不仅是成矿物质的载体,所产生的压应力和热能也成为成矿流体运移的驱动力。建立了相应的成矿模型。更多还原

【Abstract】 Tectonically located in the middle of the North China plateform, Handan-Xingtai area is an important locality for skarn iron deposits. Currently ,more than 100 ore deposits have been discovered. With diverse shapes and different scale, the ore bodies were hosted along the contact belt between the intrusives and carbonate rocks. Folds are the dominating ore control and host structures. The ore type is monotonous magnetite. The mineralization and alteration are characterized by obvious zoning.The intermediate-acid intrusives that related to skarn Fe deposits formed two complexs: Fushan complex and Wuan complex. Fushan complex belongs to the positive emplacement mechanisrn. Within the pluton, the ore bodies show themselves as xenoliths, and there is still deep-seated metallogenic potential far away from the contact zone between the intrusives and the carbonate rock. Wu’an complex belongs to the passive emplacement mechanisrn. The xenoliths seldom occurred within the pluton, and the iron deposits are mainly hosted along the contact zone while a minority within the carbonate country rocks. The anticlines formed under the condition of the positive emplacement are the important host structure.The melt-fluid inclusions and the melt inclusions in skarn minerals were firstly discovered in this region, and their phase state, homogenization temperatures and salinity were observed and tested. The origin of these two kinds of inclusions were discussed: they were produced by the re-melting of the skarn that formed due to the original contact metasomatism.Theδ18Ovalues of the skarn minerals range from 5.3‰to 8.5‰, with 13CV–PDB values from–2‰to 11.2‰,δDV-SMOW values from–80‰to -109‰,and correspondingδ18OH2O values from 0.84‰to 8.62‰. Theδ18Ovalues of the magnetite range from from 3.7‰to 5.1‰, with 13CV–PDB values from -5.6‰to -24.9‰,δDV-SMOW values from–79‰to -156‰,and correspondingδ18OH2O values from 10.61‰to 11.41‰. It suggested that the ore-forming materials were mainly mantle-derived with a little hybridization of crustal materials.Through chronological study of Xishimen iron deposit, the 40Ar-39Ar age ofphlogopite that coexisted with magnetite shows that the main metallogenic stage occurred around 133 Ma.Plutons related to iron deposits were formed by multiple magmatic pulses. The early intrusions provided ore-forming materials during albitization, The magmatic hydrothermal solutions produced by the later intrusions were the carrier of ore-forming materials, and the compressive stress produced by hydrothermal solutions gave dynamism for the migration of ore-forming materials. Based on the mentioned above, an ore-forming model was builded.更多还原