A Study on the Banded Iron-Formation Hosted Iron Ore Mineralization in Gandhamardan Hill Kaushik Kiran Ghosh Chapter 3: Iron Ores

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1 3 3.1 Iron ores: World occurrences of BIF-hosted iron ores a review Banded iron-formation hosted iron ore deposits account for the majority of current world production and contribute >31,000 Mt high-grade hematite resources of iron ore (Dalstra and Guedes, 2004). Banded iron-formation (BIF) is a rock of Precambrian age. They are all confined in Precambrian cratonic shields and almost all the granulite-greenstone successions of cratonic mass throughout the world contain prominent banded iron-formations as one of its member. However, most of the BIF-hosted iron ore deposits were formed in the post-depositional time indicating their epigenetic ore genesis. Major belts containing banded iron-formation hosted iron ores, which are gigantic in size in terms of their initial tonnage, are: Hamersley Range in Western Australia (~2.5 Ga); The Transvaal Supergroup (Kuruman and Griguatown iron-formations) (~ Ga), Sishen-Beeshoek and Thabazimbi districts, South Africa; Labradore Trough, Quebec-Newfoundland, Canada (~2.1 Ga); Lake Superior region, USA- Canada (~ Ga); Gunflint and Biwabik, North America ( Ga); Quadrilatero Ferrifero, Minas Gerais (~2.3 Ga), Carajás Formation (2.6 Ga) and Urucum Region (0.8 Ga), Brazil; Krivoy Rog Supergroup, Ukrainian Shield (~2.2 Ga); Singhbhum-Bonai-Keonjhar-Mayurbhanj region, Odisha-Jharkhand and Dalli- Rajhara districts, Chhattisgarh, India (~3.0 Ga); Imataca Complex, Venezuela (~3.4 Ga); Liberia-Sierra Leone, Liberian Shield (~3.0 Ga); and Nabberu Basin, Australia (~2.1 Ga) (Figure 3.1). In these deposits the minable iron ores represent horizons that are originated by supergene processes from BIF or they represent the original hydrothermal ore body emplaced through replacement of BIF. Page 125

2 The detailed classification of iron ore deposits is available in the Table 2 (p. 655) of Clout and Simonson (2005) and the total reserves of iron ore and reserves of different countries are given in Figure 3.2 (Web-1). 3.2 Banded Iron-formation hosted iron ores: world occurrences Continents that contain Precambrian greenstone belts and other supracrustals are major repositories of banded iron-formation hosted iron ores. Australia is one of the leading iron ore producers of the world and alone produces 530 million tonnes of ore in 2013 which is 18% of the world total of that year. This production comes from the banded iron-formation (BIF)-hosted high-grade hematite ore deposits of the Archaean-Proterozoic Hamersley Group of rocks of Pilbara Region, Western Australia (Morris 1985, Harmsworth et al. 1990). Australian ore exports supply about 50% of the iron ore requirements of the major Pacific Rim steel producers in Japan, Korea and Taiwan and a significant portion of the iron ore demands of China and Western Europe (Poveromo, 1999). There are number of BIF horizons in the Pilbara region, but the main areas of iron ore are the Marra Mamba and Brockman Iron Formations in the Hamersley Province, and the older Nimingarra Iron Formation in the Yarrie area. The Marra Mamba and Brockman ores are martite-goethite (M-G) ores. The high-grade hematite ore mainly occurs within the Newman Member of Marra Mamba Formation but also occurs in parts of the Nammuldi Member along with low-grade limonitic ore. Mt Whaleback hematite ores are found within the Dales Gorge and Joffre Members of the Brockman Iron Formation. The Mt Whaleback ores are essentially free of goethite. In the Newman area, there are deposits to the north and east of Mt Whaleback, along the Ophthalmia Range, continues up to Jimblebar. BIF-hosted Iron Deposits (BID) include the low-phosphorus Brockman, Marra Mamba and high-phosphorus Brockman types. Examples of the low- phosphorus Brockman type are Mt. Tom Price, Mt. Whaleback and Paraburdoo deposits. Marra Mamba ore type includes Homestead/Nammuldi, Marandoo, Mining Area C (MAC), West Angelas and Hope Downs deposits. High-phosphorus Brockman type includes Brockman No. 2, West Turner Syncline, Paraburdoo Western Range and Koodaideri deposits. Page 126

3 In North American, the so called famous iron-formation of Lake Superior Region is situated on the south-western margin of the Canadian Shield, which covers much of Eastern Canada. The area includes several separate iron-ore ranges, some of which lie within United States and others in Canada. The Lake Superior Region extends in Ontario (Canada), Michigan, Minnesota and Wisconsin state (USA). Iron ore deposits of this region are related to sedimentary banded iron-formations of the Archaean and Proterozoic successions of the Keewatin and Animikee Groups in the United States and the Keewatin and Timiskamian Groups in Canada. (Poveromo, 1999). The iron ore deposits of the famous Mesabi Range occur in the Animikie Biwabik Iron Formation. Paleoproterozoic Animikie basin extends north-eastward from the Mesabi Range (containing the Biwabik Iron Formation) of north-central Minnesota to the Gunflint Range of Ontario. The iron ore minerals of the Mesabi Range are mainly magnetite taconites. The Labrador Trough area of northern Quebec and Labrador contains extremely large reserves of ore and has produced more than 2 billion tonnes of iron ore since In South America BIF-hosted iron deposits predominantly occur in Brazil. The biggest deposits are located within the Proterozoic Cauê Formation, Itabira Group (The Minas Supergroup) in the Quadrilátero Ferrífero district of Minas Gerais State (Spier et al., 2008; Klein and Laderia, 2000). The Quadrilátero Ferrífero (Iron Quadrangle) owes its name to an almost rectangular arrangement of huge banded iron-formations or BIF (Dorr, 1969). The Quadrilátero Ferrífero is an area of about 7000 km 2 of central Minas Gerais located approximately 450 km north of Rio De Janeiro. The economically important, giant iron ore deposits are hosted in metamorphosed banded iron-formations, referred to as itabirites (Rosière and Rios, 2004), of the Paleoproterozoic Itabira Group. Concordant and discordant, hard, massive ore bodies consisting of magnetite-martite and hematite occur together with structurally controlled, heterogeneously deformed, schistose, high-grade bodies and with friable weathered ores. Iron ore deposits are also hosted by Neoproterozoic BIFs (both jaspilites, and glaciomarine dropstone bands) of Jacadigo Group (Rapitan type) in Urucum district in the Brazil state of Mato Grosso do Sul (Klein and Ladeira, 2004), near the international border of Brazil and Bolivia. Besides Brazil, BIFs in Southern America Page 127

4 are also well-known from Venezuela e.g. iron deposits in the Cuadrilatero Ferrifero de San Isidro hosted by BIFs of the Imataca belt (Ferenčic, 1969). Iron ores deposits are found throughout the African continent and the current largest ore deposit is in Sierra Leon. Some major iron deposits are found in Nimba in Liberia, Penge, Griqualand and the Kaapvaal in South Africa. In South Africa, very large Sishen, Beeshoek and Kolomela iron ore deposits of the Transvaal Supergroup and another major Thabazimbi deposit in the Limpopo province, situated at the base of the Penge Iron Formation are important. The iron formations of the Transvaal Griquatown belts of South Africa (Kuruman Iron Formation in the Griquatown belt of Northern Cape Province and Penge Iron Formation of Transvaal) occur in the lower part of the Transvaal Supergroup, overlying thick dolomite (Beukes, 1973). High grade hematite ore at the Thabazimbi Mine, Limpopo Province, occurs as stratabound bodies in the Early Paleoproterozoic Penge Iron Formation of Transvaal Supergroup. The Sishen, Beeshoek and Kolomela iron ore deposits, like Thabazimbi, also occur in the Kuruman Iron Formation of Transvaal Sequence. In present Europe, iron-formations of the greatest economic value are limited to three localities: the Kursk Group (Belykh et al., 2007) and the Kola Peninsula in Russia and Ukraine. BIF also outcrops in Finland e.g. the Pääkkö Iron Formation (Bekker et al., 2010). Kursk Magnetic Anomaly region of Russia and the Krivoy Rog basin in the Ukraine are the major iron production centres. In Western Europe, Austria, Norway and Sweden play the major role in production. They are not giant BIF-hosted deposits. In Asia, huge amount of iron ores are available in India, China and few other countries. Amongst the neighbouring countries of India, Afghanistan has large, bedded iron deposits that are located 140 km west-northwest of Kabul near Hajigak Pass. Iron ore production of China has increased very rapidly, but the ore grades are very low. Approximately 25% of that total reserve is in Pre-Cambrian banded metamorphic ores of magnetite-hematite which are found at Anshan and in the northern and north-eastern provinces (Poveromo, 1999). Rest are either bedded Page 128

5 oolitic or Metasomatic skarn deposits which are beyond the scope of the present study. Antarctica is the only continent which cannot produce a single gram of direct shipping ore (DSO) though the continent is not free from protolith of iron. The most extensive iron deposits in Antarctica are in East Antarctica viz. western Wilkes Land and western Enderby Land, where a Precambrian banded iron-formation (jaspilite) is found with Fe concentration~34%. 3.3 Banded Iron-formation hosted iron ores: Indian occurrences India has a vast reserve of iron ore deposits in the tune of 28.5 billion tonnes. As of April 1, 2010, hematite rich iron ore resources amounted to 17,882 million tonnes. Of this, 8,093 million tonnes (45%) were under the reserves category and the balance 9,299 million tonnes (55%) were under the resource category. The Magnetite rich iron ore reserves amounted to 10,644 million tonnes (FICCI report, 2013). The major iron ore deposits of India occur in the States of Jharkhand, Odisha, and Chhattisgarh, Andhra Pradesh, Tamil Nadu, Karnataka and other smaller deposits occur in Goa and Maharashtra. The ten main states that are in active production are shown in the following table: State Reserves Resources Total Hematite Magnetite Hematite Magnetite Hematite Magnetite Andhra Pradesh 152, ,261 1,463, ,478 1,463,561 Chhattisgarh 900,110-2,391,714-3,291,824 - Goa 469,844 50, , , , ,169 Jharkhand 2,304,142 3,391 2,292,478 6,879 4,596,620 10,269 Karnataka 876, ,437 1,281,811 7,663,347 2,158,678 7,811,784 Madhya 56, ,632 83, ,446 83,435 Pradesh Maharashtra 13, , , Odisha 3,313, ,617, ,930, Rajasthan 7,139 4,225 23, ,652 30, ,877 Tamil Nadu , ,876 Total 8,093, ,941 9,788,551 10,412,540 17,882,098 10,644,481 Indian Reserve Geologically, BIF-hosted iron ores deposits are located in two horizons Page 129

6 A. Archaean Schist belts and/or Granite-Greenstone belts: Odisha, Jharkhand, Karnataka, Chhattisgarh, Goa (high grade deposits) B. Granulite terrain of South India: Tamil Nadu, Andhra Pradesh and Kerala. Compositionally, ore of BIF type of these regions are characterised as massive ores, laminated or biscuity ore, powdery ores or blue dust. Sedimentary iron ore deposits of siderite and limonitic composition (30-40% Fe; Bog iron deposit) are associated with Iron stone shales of Lower Gondwana age in coal field areas of Bihar, W.B. and Assam (GSI-DID, IRON ORE, 2010). Some important statistics related to Indian iron ore deposits are: 1. As on 2005, India s total in situ resources of hematite and magnetite ores are estimated at 25,249 million tonnes, of these hematite resources constitute million tonnes whereas magnetite resources are placed at 10,619+ million tonnes (p. 14, GSI-DID, IRON ORE, 2010). The total reserve increases upto another 3 million tonnes due to discovery of new reserves and India is slated to become the second largest producer of steel by 2015 (Web-2). 2. About 59% of high-grade hematite ores are restricted within the Archaean- Proterozoic banded iron-formation hosted supracrustals belts. Major resources of haematite are located in Odisha million tonnes (33%), Jharkhand - 4,597 million tonnes (26%), Chhattisgarh - 3,292 million tonnes (18%), Karnataka - 2,159 million tonnes (12%) and Goa million tonnes (5%). The balance resources of haematite are spread in Andhra Pradesh, Assam, Bihar, Madhya Pradesh, Maharashtra, Meghalaya, Rajasthan and Uttar Pradesh (Indian Minerals Yearbook 2013) 3. India's 97% magnetite resources are located in four states, namely, Karnataka - 7,802 million tonnes (73%) followed by Andhra Pradesh - 1,464 million tonnes (14%), Rajasthan million tonnes and Tamil Nadu million tonnes (5% each). Assam, Bihar, Goa, Jharkhand, Kerala, Maharashtra, Meghalaya, Nagaland and Odisha together account for the remaining 3% resources (Indian Minerals Yearbook 2013). 4. There were 270 reported mines in as against 313 in Among them, 34 mines were in the public sector and 236 in private sector. Besides production of iron ore was reported as an associated mineral by 14 mines (Indian Minerals Yearbook 2013). Page 130

7 Mukhopahyay et al (2008b) reviewed the geology and genesis of Indian iron ores and identified four major iron producing districts. These are (i) the Noamundi-Koira valley in the Singhbhum Craton, (ii) the Bailadila-Dalli-Rajhara in the Bastar Craton, (iii) the Donimalai-Hospet, as well as (iv) the Goa deposits in the eastern and western parts of the Dharwar Craton respectively. Based on the geologic setting, mineralogy, petrography and geochemistry, a supergene-modified hydrothermal genesis, similar to that of the giant Serra dos Carajás district in Brazil, has been proposed for the Indian iron ores. Hematite and martite-rich hard ores formed by early hydrothermal events underwent extensive chemical weathering in the Indian humid-monsoonal climate leading to supergene enrichment and formation of soft sprolitic hematite ores and surfacial goethite-rich ores (Beukes et al., 2008). Bhattacharya et al. (2007), from their geochemical study of iron oxide phases in the BIF from various localities in the Archaean Jharkhand-Odisha region, observed REE patterns with strong positive Eu anomalies, which is indicative of basinal hydrothermal fluids as source of Fe for the major part of iron ore bodies. The varying positive Eu anomalies also point toward mixing of hydrothermal fluids of varying temperatures with the bottom seawater. Furthermore, these authors proposed anoxic nature of the Archaean bottom sea water from the submarine influx of reduced Fe and absence of Ce anomaly in the BIF. Geochemical study of Roy and Venkatesh (2009) indicates a model for the formation of BIF similar to modern hydrothermal systems at mid-oceanic ridges. All the recent studies of Indian ore clearly advocate in favour of prevalent hydrothermal model or a model dominated by hydrothermal activity followed by supergene alteration. The national steel policy has envisaged the target of steel production at 110 million tonnes by which will require ~170 million tonnes of iron ore. A target set in the national steel policy suggests a production of 300 million tonnes of iron ore by to meet export and domestic demand (GSI-DID, IRON ORE, 2010). The Indian industry will remain comfortable upto 2070 with its present industrial growth, resource position and an annual export of 100 million tonnes of ore. Page 131

8 FIGURES Figure 3.1: Country-wise reserve of iron ore [based on U.S. Geological Survey, Mineral Commodity Summaries, February 2014 & 15] Page 132

9 Figure 3.2: World distribution of iron ore after Beukes et al., Page 133