Name & composition of ores of Iron.

Describe Iron ore deposits of India with references to their mode

of occurrence, association & geographic distribution.
The ores are usually rich in iron oxides and vary in colour from dark grey, bright yellow, or deep
purple to rusty red. The iron is usually found in the form
of magnetite (Fe3O4,72.4%Fe), hematite (Fe2O3, 69.9% Fe), goethite (FeO(OH),
62.9%Fe), limonite (FeO(OH)·n(H2O), 55% Fe) or siderite (FeCO3, 48.2% Fe).

ORIGIN AND CLASSIFICATION OF IRON ORE DEPOSITS

Iron ores may be classified in to six groups according to their mode of origin and occurrence:

1. Igneous- Magmatic segregation

2. Contact metamorphic deposits
3. Lode deposits
4. Replacement Deposits
5. Bedded or sedimentary deposits
6. Residual and superficial deposits, including laterite.

The iron ores of India can be divided in to three major groups according to the origin. The first and most important
group comprises the banded ferruginous formations of Pre-Cambrian age. The second group consists of sedimentary
iron ores of sideritic or limonitic composition and the third group consists of lateritic ore derived from the sub-aerial
alteration of iron-bearing rocks, such as gneisses, schists, basic lavas, etc., under tropical conditions, resulting in the
concentration of hydrated oxides of iron often associated with those of aluminium and manganese. Lateritic caps are
wide spread in India.

In India the leading producers of iron ore are Chhattisgarh, Orissa, Goa, Karnataka, Maharashtra and Andhra
Pradesh.

Iron ore is the basic resource for a nation’s development. Iron is described as the backbone of civilization. As the
major raw material for the iron and steel industry, iron ore is found in four varieties viz., Magnetite, Limonite,
Hematite, Siderite. 20% of the iron ore deposits of the world are found in India. Major iron ore deposits of India are
given in the Table given below:

Producing Centres States

Durg. Dantewada Districts Chhattisgarh
Sundergarh, Keonjhar, Mayurbhanj Districts Orissa
North Goa Districts Goa
Chickmangalore, Bellari Districts Karnataka
Name & composition of ores of Iron. Describe Iron ore deposits of India with references to their mode
of occurrence, association & geographic distribution.

MAP SHOWING IMPORTANT IRON ORE DEPOSITS OF INDIA

1.CHHATTISGARH
Chhattisgarh is the richest State in terms of mineral wealth, with 28 varieties of major minerals, including diamond.
Chhattisgarh along with two other Indian States has almost all the coal deposits in India, which led to its ‘power
hub’ strategy. All the tin ore is in Chhattisgarh. A fifth of iron ore in the country is here, and one of the best quality
iron ore deposits in the world is found in the Bailadila mines in south Chhattisgarh from where it is exported to
Japan. Rich deposits of Bauxite, Limestone, Dolomite and Corundum are found in the State. The State is lucky to
have large deposits of coal, iron ore and limestone in close proximity, making it the ideal location for the lowest
cost of production.
Bailadila range of mines is perched on the southern tip of Chhattisgarh in Dantewada District.
2. ORISSA
In Orissa, the iron ore deposits occur in the districts of Cuttack, Keonjhar and Sundergarh, Mayurbhanj,
Sambalpur, Koraput and Dhenkanal. Of these, the Keonjhar deposit is important. The principal ore is hematite with
the iron content ranging from 55 to 69 per cent.
The iron ores are associated with both the banded hematite quartzite (BHQ) and banded hematite jasper. In this
State, the most important deposits containing large reserves of high grade ore occur in the Bonai range of hills
running through Keonjhar and Sundergarh districts and comprises the well known iron ore deposits of Banspani,
Barsua, Bichhakani, Bolani, Joda east, Malangtoli, Makaranacha, Murgabera, Pirpokri, Rajabasa and Thakurani.
Mainly steel grey hematite is found in the Malangtoli block in Keonjhar district.
3. GOA
Between the Talpona river (Naibhaga) in the NW and Salginim in SE, iron ore and manganese deposits closely
associated with the pink phyllitic horizon are found in a 95 km long and 2km wide belt. These pink phyllites
resemble the shales in the well known Singhbhum-Keonjhar-Bonai iron ore region. It is a remarkable fact that the
iron ore deposits decrease in quality and quantity as one proceeds from north to south in Goa. Thus, near Nuem
and Cananquinim banded hematite magnetite quartzites occur as lensoid bodies while the manganese bearing
cherts and quartzite occur in narrow bands.

According to A.R. Gokuam there are more than thirty important iron ore deposits in Goa which on the basis of their
nature, mode of occurrence and origin could be grouped into eight major types such as:

(a) Bicholim-Pale type

(b) Sacroda-Pissurlem type
(c) Codli-Sigao type
(d) Costi-Quirlapale type
(e) Barazan-Viliena-Motto type
(f) Rivona-Columba-Canvorem type
Name & composition of ores of Iron. Describe Iron ore deposits of India with references to their mode
of occurrence, association & geographic distribution.
(g) Netorlim type
(h) Betul-Nuem type.

4. KARNATAKA
In Karnataka, there are two main types of iron deposits, the lateroid hematitic iron ore concentrations with minor
limonite and goethite and magnetite ore deposits. Workable deposits of iron chiefly hematite carrying 55 to 63
percent of iron content with phosphorous between 0.05 and 0.12 percent are known to occur.

Karnataka has the richest resources of iron ores of the order of 1000 million tons of Karnataka and 25000 million
tons of magnetic ores. Major deposits occur in Bellary, Chickmagalur and Chitradurga districts. Some of the richest
deposits analyzing to more than 62 per cent iron ore occur in Bellary.

The more important districts are the following:

Name of district Location of iron ore deposits

Bellary Bellary, Hosepet and Sandur
Bijapur Amingarh
Chickmagalur Bababudan hills, Kudremukh, Gangamula
Chitradurga Hiriyur, Sasalu, Vajra
North Kanara Deposits on Goa border and Honavar
South Kanara Puttur taluk , Dharmasthala
Shimoga Siddarahalli, Shankaragudda, Kodachadri
Tumkur Chickanayakanhalli

5. MAHARSHTRA
Iron ore deposits in Maharashtra occur in Chandrapur, Gadchiroli, Bhandara and Sindhudurg districts. They are
mostly concentrated in the Vidarbha region where ore bodies occur as lenses in banded hematite quartzites
belonging to ‘Iron Ore Series’. The iron minerals are hematite and magnetite.
In Chandrapur district iron ore deposits occur at Asola, Lohara, Ratanpur and Pipalgaon localities. Out of these the
Lohara deposit is the most important followed by Asola and Pipalgaon. In Gadchiroli district iron ore deposits occur
in three parallel hill ranges i) Surajagarh hill range, ii) Damkod Wadvi hill range iii) Bhamragarh hill range. Several
deposits are present but the deposit occurring in Wureea hill range is very important in nature. The Wureea hill
deposit is in the form of a lenticular body associated with banded hematite quartzite and ferruginous phyllites
belonging to ‘Iron Ore Series’. The ore which is predominantly hematite, occur as massive, laminated, soft and
porous type.
6. ANDHRA PRADESH
In Andhra Pradesh the iron ore deposits are mainly confined to Rayadurg area in Anantpur district, Bayaram in
Khammam district, Gani-Ramallokota and Veldurthi areas in Kurnool district, Gandrai area in Krishna district and
around Konijedu in Prakasam district. Dharwar, Cuddapah and Gondwanas are the main units with which iron ore
of the States are associated. There are minor lateritic ores derived from Deccan Trap.
In Adilabad district iron-ore occur associated with Upper Gondwana rocks in Sirpur areas whereas banded
hematite quartzites are reported from Chityala, Kallada and other places. In Anantpur and Chittoor districts iron-ore
occurs associated with the Dharwars. In Khammam and Warangal districts iron ores are associated with Pakhals
and also Dharwar strata.