Iron ore is widely distributed in China, and 3 1 province (city, autonomous region) has iron ore reserves. On the basis of predecessors' achievements, the "National Mineral Resources Potential Assessment" takes into account the division scheme of Grade II and III metallogenic belts in China and the characteristics of iron ore itself, and predicts the working areas and metallogenic prospects of iron ore in various provinces. Nationwide, it is divided into Altai, Xizhun, Dongzhun, Southwest-West Tianshan, East Tianshan-Beishan, West Kunlun, East Karakorum, Altun, Qilian, Gangdise, Tanggula, Sanjiang, Kangdian (Panxi-central Yunnan), Bayan Obo-Langshan, Helan Mountain, Daxinganling and Xiaoxing 'anling. Qijiang-Fuling, Shuicheng-Kaili, Guixi-East Yunnan, Jiangnan (Jiangxi, Hunan and Guangxi), Nanling, the middle and lower reaches of the Yangtze River, the southeast coast and Hainan (Figure 9- 1). However, due to the relatively high level of work in the eastern region and the relatively low level of work in the western region, these 36 iron ore metallogenic belts are relatively concentrated in the eastern region, and the iron ore resources are mainly concentrated in the Liaodong-Jinan iron ore metallogenic belt, the Kangdian (Panxi-Central Yunnan) iron ore metallogenic belt, the Jidong-Liaoxi iron ore metallogenic belt, the Luxi-Jiaodong iron ore metallogenic belt, the Wuyang-Huoqiu iron ore metallogenic belt, the middle and lower reaches of the Yangtze River and the southwest region.
(1) Anben ore concentration area
Located in Liaodong-Jinan iron ore metallogenic belt, it is the most important iron ore concentration area in China. The ore-bearing strata are located in Anshan Group, and the ore-bearing rock series are biotite amphibole plagioclase gneiss, biotite amphibole and magnetite quartzite, sericite quartz schist, phyllite and magnetite quartzite. Iron deposits such as Donganshan Iron Mine, Xianshan Iron Mine, Dagushan Iron Mine, Qidashan Iron Mine, Nanfen Iron Mine, Beitai Iron Mine, Gongchangling Iron Mine and Waitoushan Iron Mine are all produced, and the iron ore reserves are up to. However, the control depth of these iron deposits is shallow, and the ferrosilicon formation of Anshan Group extends to the deep in a "monocline" shape, indicating that the deep prospecting potential is great. Recently, a large-scale ore body was discovered in the deep part of Gongchangling mining area, with 70 million tons of iron ore added, including 50 million tons of rich ore. 50 million tons of iron resources (iron ore) have been newly added in Qian Qian Mountain Iron Mine; Iron ore bodies have been discovered below Qiaotou 1000 meters in Liaoning, and the iron ore resources have been submitted with a reserve of 4 billion tons and a prospect of 7 billion tons. The comprehensive exploration project recently established in Anshan area aims to submit 7.5 billion tons of iron ore resources. Therefore, the resource potential of the metallogenic belt is above 65.438+000 billion tons, and the main deposit type is sedimentary metamorphism.
Fig. 9- 1 China iron ore metallogenic belt map
(2) Panxi ore concentration area
It belongs to Kangdian (Panxi-Central Yunnan) iron ore metallogenic belt. Hercynian basic-ultrabasic rocks are well developed in Panxi ore concentration area, which creates good conditions for the formation of magmatic vanadium-titanium magnetite. * * * * Eight large-scale and nine medium-sized Panzhihua-type vanadium-titanium magnetite deposits were discovered in this area, with more than ore occurrences and mineralization points 10, and aeromagnetic anomalies near 10, and iron ore resources1000 million tons were found. There are still many aeromagnetic anomalies in the ore concentration area that have not been verified, and there is great potential for further prospecting. In addition, the deep drilling control of vanadium-titanium magnetite is less, and the deep storage potential is huge. In 2008, 223 million tons of new resources (iron ore) were added to the deep side of Jipingping Iron Mine in Miyi County. The main deposit type in this area is magmatic deposit. Proterozoic marine volcanic rocks are developed in central Yunnan, and Dahongshan iron mine has great prospecting potential.
(3) Jidong ore concentration area
It belongs to the Jidong-Liaoxi iron ore metallogenic belt, and the ore concentration area is an important distribution area of sedimentary metamorphic iron ore after Anben area. Geographically, this area is located in the uplift area of the northern margin of North China Craton (east of inner mongolian axis), and the metamorphic strata of Early Precambrian are widely developed, especially the Archean metamorphic strata are very developed in this area, including Archean, Middle Archean and NeoArchean strata, as well as Proterozoic strata. It is worth noting that there are banded ferrosilicon formations (iron deposits) of different scales in the early Precambrian strata of the above different times, such as Qianxi Group (Shuichang Iron Mine), Zunhua Group (Shirengou Iron Mine), Luanxian Group (Sijiaying Iron Mine), Zhuzhangzi Group (Zhalanzhangzi Iron Mine), Miyun Group and Sihetang Group in Miyun area, and all of them have iron deposits in six sets of crustal rocks. Metamorphic supracrustal rocks mainly include volcanic rocks-ferrosilicon formation, volcanic rocks-ferrosilicon formation containing sedimentary rocks, volcanic rocks-sedimentary rocks-ferrosilicon formation and sedimentary rocks-ferrosilicon formation containing volcanic rocks. Known large and super-large iron deposits include Sijiaying, Shuichang, Shirengou, Mengjiagou, Shachang, Zhalanzhangzi and Malanzhuang, and a number of small and medium-sized iron deposits. The proven reserves of iron ore resources in this area are more than 6 billion tons, accounting for more than 10% of the whole country. However, it has been found that the exploration depth of iron deposits is shallow, and there are magnetic anomalies consistent with the occurrence of iron-bearing formations, such as Zunhua-Qianxi arc aeromagnetic anomaly belt, Sigezhuang-Changli Dafuzhuang1:200,000 aeromagnetic anomaly high value belt, etc. Presumption is a sign of deep iron ore body; There are low-slow aeromagnetic anomalies in the Quaternary coverage area, such as the low-slow magnetic anomalies in Lulong-Xiaguanying area and the low-slow magnetic anomalies in Huoshiying area of Feng Run, which are presumed to be caused by sedimentary metamorphic iron deposits. In recent years, breakthroughs have been made in prospecting for Xingshan iron mine in eastern Hebei. Four boreholes have been drilled, see 3-6 layers of ore. The maximum thickness of ore is 65,438+0,665,438+0.00 m, the iron-rich ore is 54.49 m, and the mFe grade can reach about 33%. The total amount of 333 kinds of iron ore resources in Hexingshan mining area of Ermayina is1.700 million tons. Macheng Iron Mine in Luannan County, discovered in 2005, has obtained 654.38+0.2 billion tons of resource reserves (iron ore) after detailed investigation, and there are still 400 million tons of resource potential to be exploited.
(4) Luxi ore concentration area
It belongs to the Luxi-Jiaodong iron ore metallogenic belt. The iron-bearing horizons in this ore concentration area mainly include the Yanlingguan Formation of Neoarchean Taishan Group, biotite granulite of Shancaoyu Group, magnetite quartzite and sericite phyllite, chlorite sericite phyllite, slate, metamorphic volcanic rocks of Proterozoic Jining Group and magnetite quartzite. The northern part of this area is Jinan Changqing-Pingyin-Dongping-Wenshang high positive magnetic anomaly belt, and the central part is Wenshang-Jining north low negative magnetic anomaly belt and Jining-Jiajia. In the south, there are low negative magnetic anomaly belts in Shan County and high positive magnetic anomaly belts in Longwangmiao-Caitang area in the south of Shan County. Sedimentary metamorphic iron deposits have been proved in Cangsong, Hanwang and Dongping. Recently, Jining iron ore was discovered in the iron-bearing formation of Jining rock group, with an estimated resource of 3 billion tons, indicating that the deep prospecting potential is huge.
(5) Wuyang ore concentration area
It belongs to Wuyang-Huoqiu iron ore metallogenic belt. The types of iron ore in this ore concentration area are mainly sedimentary metamorphism, including sedimentary metamorphic iron ore in Archean banded iron formation (Anshan type) and ultrabasic rock metamorphic sedimentary metamorphic iron ore (Zhaoanzhuang type). The metamorphic rock series of Taihua Group is widely distributed, with stable horizons and many iron-bearing horizons, and iron deposits such as Jingshansi, Xiaohanzhuang, Yaozhuang, Lu Qian and Zhao An Zhuang have been discovered. There are many weak aeromagnetic anomalies to be solved; It has been found that the strike and dip angle of iron ore are not controlled by the ore body boundary, and the recovery degree of deep iron ore is low. In the eastern part of Chendian-Liancun area in Xincai County, iron ore deposits were discovered by drilling holes ZK 1705 and ZK 1270 1 in the geological survey project, with a cumulative thickness of more than 70 meters. The shallow coverage area in the deep and periphery of Wuyang iron ore field and the shallow-middle coverage area in Wuyang-Xincai area are very low, and the prospecting prospect is very broad.
(6) Huoqiu ore concentration area
It belongs to Wuyang-Huoqiu iron ore metallogenic belt. The ore-bearing formation in the ore concentration area is the metamorphic rock series of the Neoarchean Huoqiu Group. It has been found that Dawangzhuang Iron Mine, Wang Ba Iron Mine, Huoqiu Wangjie Iron Mine, Liutangfang Iron Mine, Zhangjiaxia Iron Mine, Wanzhuang Iron Mine, Yanwan Iron Mine and Tuanshan Iron Mine, and the deep and peripheral Precambrian iron mines in Huoqiu iron mine area have great prospecting potential.
(7) Daye ore concentration area
Daye area is located at the western end of the metallogenic belt in the middle and lower reaches of the Yangtze River. The iron ores in this ore concentration area are mainly distributed in the west side of the NE-trending Neocathaysia composite uplift belt from Sun Yicheng to Damushan, including Sun Yicheng, Jinshandian, Lingxiang and Tieshan rock bodies, all of which are banded with large intrusions and a few small intrusions. Most iron ores are skarn-type, which mainly occur in the contact zone between Yanshanian intermediate-acid intrusive rocks and carbonate rocks of Daye Formation of Lower Triassic and sandstone shale of Puyin Formation of Middle-Upper Triassic. Secondly, it breaks between layers of carbonate rocks not far from the contact zone, and there are traces of carbonate rocks and xenoliths near the contact zone. The occurrence and range of contact zone often control the shape and scale of ore bodies. Despite the high degree of work, many iron deposits have been discovered, but the exploration depth is shallow and the deep prospecting potential is great. Recently, a new ore body was discovered in the deep part of Daye Iron Mine, with an increase of 23 million tons of iron ore.
(8) Ningwu-Luzong ore concentration area
The ore concentration area is located in Ningwu basin and Luzong basin in the east of the iron ore metallogenic belt in the middle and lower reaches of the Yangtze River. The ore concentration area is famous for producing porphyry iron ore, and 39 large and medium-sized iron ore deposits have been discovered, with proven iron ore reserves of10.95 billion tons. The aeromagnetic anomalies of Gaogongshan in the north and east of Ningwu are basically similar to the known magnetic anomalies of Meishan, Woergang and Jishan iron mines, and there may be large-scale rock masses related to iron mineralization in its deep part, and Meishan iron mine is being searched. Longqiao iron mine and Luohe iron mine have been discovered in Luzong basin, but the low and complex magnetic anomalies at the edge of the basin have not been paid attention to. Luohe iron mine, Nihe iron mine, Shan Yang iron mine, Longqiao, Mabianshan, Hejiaxiaoling and Huangtun are located in the northeast anomaly zone of Luohe-Qiaokou and the east-west anomaly zone of Huangtun-Fanshan respectively, which are similar to the metallogenic geological conditions of Niutoushan, Lijialou, Qingshuitang, Yandun and Huangyinchong, with gravity and magnetic anomalies around them and great prospecting potential. The areas of Zongyang-Jinqiao-Chengshan and Zongyang-Jinqiao-Yutangang-Gong Hui are gravity and magnetic anomaly zones with low degree of work, which have the prospect of finding porphyry iron deposits. The newly discovered Nihe porphyry iron deposit in recent years is estimated to have iron resources exceeding 654.38 billion tons, and the average grade of total iron reaches 40%.
(9) Awulale ore concentration area
Located in the southwest-west Tianshan iron ore metallogenic belt. The ore concentration area is located at the intersection of Junggar arc-basin system, Tarim block and Isei Ke-Yili block, with complex geological structure and favorable metallogenic geological conditions. In the north, it is the Poroch-Nu Paleozoic island arc belt of the Yike-Yili landmass in Isei, and in the south, it is the late Paleozoic rift system in Ciric, Yi Shi. This area corresponds to the Avulale-Yi Shi Ciric Rift System in the Late Paleozoic, and extends along the Avulale Mountain and the eastern section of Polo Horo. It is the main part of Xinyuan iron ore belt, and copper, iron and gold polymetallic minerals related to Carboniferous-Permian volcanic activity and its volcanic rocks are developed. Representative iron deposits include Chagangnuoer large iron deposit, Kebutai iron (copper) deposit, Liyuan iron deposit, Zhibo Glacier iron deposit and reserve iron deposit. In recent years, through the exploration of Chagangnuoer, Zhibo and Songhu iron mines, the proven iron ore resources have reached a large scale or have great prospects, forming a concentrated area of marine volcanic iron ore with great prospecting potential.
Secondly, the spatial distribution of different types of iron ore.
Sedimentary metamorphic iron ores are widely distributed, but mainly distributed in Liaodong-Jinan, Jidong-Liaoxi, Wutai, Lvliang-Zhongtiaoshan, Baiyunebo-Langshan, Luxi-Jiaodong, Wuyang-Huoqiu and other iron ore metallogenic belts in the North China Craton and its surrounding areas, and also in Qilian, Hainan, Nanling and Qinling.
Magmatic iron deposits are mainly distributed in the Kangdian (Panxi-Central Yunnan) metallogenic belt, followed by the Jidong-Liaoxi metallogenic belt. In addition, there are sporadic distribution in the eastern Tianshan-Beishan, Daxinganling, Luxi-Jiaodong and southeast coastal metallogenic belts.
Contact metasomatism-hydrothermal iron ore is widely distributed, but mainly distributed in the middle and lower reaches of the Yangtze River, Hanxing-Linfen, Luxi-Jiaodong and other iron ore metallogenic belts in eastern China.
Marine volcanic iron ore deposits are mainly distributed in Kangdian (Panxi-Central Yunnan), Southwest-West Tianshan, Altai and East Tianshan-Beishan metallogenic belts, while other metallogenic belts are less important. Continental volcanic iron deposits are mainly distributed in the middle and lower reaches of the Yangtze River, followed by the Sanjiang metallogenic belt in the southwest, and other metallogenic belts are scattered.
Sedimentary iron ore is widely distributed. However, marine sedimentary iron ores are mainly Long Xuan iron ore in Wutai metallogenic belt and Ningxiang iron ore in Jiangnan metallogenic belt. There are few continental sedimentary iron ores in the Qijiang-Fuling metallogenic belt, which are mainly Qijiang-type iron ores.
Weathered leached iron ore is widely distributed in various metallogenic belts in southern China, but it has little industrial significance.
Thirdly, the spatial distribution of iron ore in different periods.
The spatial distribution of iron ore in different periods is obvious. Archean-Proterozoic iron ore is Anshan-type sedimentary metamorphic iron ore, and its spatial distribution is the spatial distribution of sedimentary metamorphic iron ore. Mesoproterozoic iron deposits are distributed in Wutai, Jidong-Liaoxi, Nanling, Qilian, Baiyunebo-Langshan, East Tianshan of Xinjiang, Central Inner Mongolia, Kangdian (Panxi-Central Yunnan) and other metallogenic belts. The deposit types mainly include Bayanobo, Xinyu, Jingtieshan sedimentary metamorphic iron ore, Long Xuan sedimentary iron ore and Damiao magmatic iron ore. There are few iron deposits in early Paleozoic, mainly distributed in Qilian and Qinling metallogenic belts, and the deposit types are mainly magmatic and contact metasomatism-hydrothermal; Late Paleozoic iron ore deposits are mainly distributed in Altai, Southwest-West Tianshan, East Tianshan-Beishan, Kangdian (Panxi-Central Yunnan), Western Hunan and Jiangnan (Jiangxi, Hunan, Guangxi) and other iron ore metallogenic belts, with Monkou-type and Chagangnuoer-type marine volcanic iron deposits, Panzhihua-type magmatic iron deposits and Ningxiang-type sedimentary iron deposits as the main ones. Mesozoic iron ore is widely distributed, but mainly distributed in the middle and lower reaches of the Yangtze River, Hanxing-Linfen, Luxi-Jiaodong, the southeast coast, Daxing 'anling and Xiaoxing 'anling in eastern China. The deposit types are mainly Daye type, Hanxing type contact metasomatic hydrothermal type and Ningwu type continental volcanic rock type iron deposits related to the activation of North China Craton. Cenozoic iron ores are mainly distributed in various metallogenic belts in southern China, mainly weathered and leached iron ores.