Review of geology, alteration and origin of iron oxide–apatite deposits in the Cretaceous Ningwu basin, Lower Yangtze River Valley, eastern China: Implications for ore genesis and geodynamic setting
Review of geology, alteration and origin of iron oxide–apatite deposits in the Cretaceous Ningwu basin, Lower Yangtze River Valley, eastern China: Implications for ore genesis and geodynamic setting
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DOI：
10.1016/j.oregeorev.2011.07.008
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发表时间：
2011-12
影响因子：
3.3
通讯作者：
Jin‐Jie Yu;Yuchuan Chen;J. Mao;F. Pirajno;Chao Duan
中科院分区：
文献类型：
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作者：
Jin‐Jie Yu;Yuchuan Chen;J. Mao;F. Pirajno;Chao Duan
长江流域成矿带宁武白垩纪火山-沉积盆地内磁铁矿、赤铁矿密集分布区主要有3个：北部梅山存款区，中部洼山、南山、陶村和南部中旧、孤山。宁武盆地的成矿作用主要与次火山侵入岩有关，主要由辉长-闪长斑岩和（或）辉长-闪长岩组成。这些矿床的蚀变分带明显，包括：（1）上部浅色带的泥质、高岭石、二氧化硅、碳酸盐和黄铁矿蚀变;（2）中部深色带的透辉石、氟磷灰石-磁铁矿、金云母和含氟磷灰石-磁铁矿的石榴石;（3）下部浅色带的广泛钠长石蚀变。而姑山铁矿存款则没有下部浅色带和中部深色带，主要蚀变类型为硅化、高岭土化和碳酸盐化。宁武盆地的氧化铁-磷灰石矿床是典型的岩浆-交代成因矿床，与斯堪的纳维亚半岛的基律纳型矿床在矿物组合、矿石组构、矿体产状、围岩蚀变等方面具有相似性。宁武盆地的氧化铁-磷灰石矿床以磁铁矿和赤铁矿为主，并夹有透辉石或阳起石和磷灰石脉石。它们形成于裂谷或伸展环境，成矿作用与碱性岩浆作用有关。岩浆活动与成矿作用的时间间隔很短。
In the Cretaceous Ningwu volcano-sedimentary basin in the Yangtze River Valley metallogenic belt, eastern China, there are three areas with a dense distribution of magnetite or hematite deposits: the Meishan deposit in the north; Washan, Nanshan and Taocun deposits in the center; and the Zhongjiu and Gushan deposits in the south. The mineralization in the Ningwu basin is associated mainly with subvolcanic intrusions, consisting of gabbro–diorite porphyry and/or gabbro–diorite. Alteration zoning of these deposits is pronounced, and includes: (1) an upper light colored zone of argillic, kaolinite, silica, carbonate and pyritic alteration (2) a middle dark colored zone of diopside, fluorapatite–magnetite, phlogopite, and garnet with fluorapatite–magnetite; (3) a lower light colored zone of extensive albitic alteration. However, at the Gushan iron deposit, the lower light colored zone and the middle dark colored zone are absent, whereas the principal alteration is represented by silicification, kaolinization, and carbonatization. The iron oxide–apatite deposits in the Ningwu basin are typically magmatic–metasomatic origin and are similar to the Kiruna-type deposits in Scandinavia, particularly with respect to mineral assemblages, fabric and structure of the iron ores, occurrence of the orebodies and wall rock alteration. The iron oxide–apatite deposits of the Ningwu basin contain magnetite and/or hematite, with diopside or actinolite and apatite gangue. They were formed in a rift or extensional environment and the mineralization is associated with alkaline magmatism. The time interval between magmatism and related mineralization is very short.