in Manipur are mainly confined to certain types of rocks such as
ophiolite suite, Oceanic Pelagic Sediment (OPS) and melanges in the
Ophiolite Belt. Amongst these, chromite, limestone and serpentinites
(as dimensional stone) are important for immediate exploitation. Other
minerals are PGE/PGM, idocrase, rock salt, etc.
chromite deposits of Manipur fall in the third category of Indian
chromite associated with the Tertiary Ophiolite Formation.
The GSI and the State Geology & Mining Division have recorded a
number of chromite occurrences of metallurgical and refractory grades
from the ophiolite belt of Manipur in Ukhrul and Chandel districts
Chromites occur as floats on the surface and in-situ pods of
varying dimensions. These chromites are found as massive boulders,
blocks, tabular bodies as well as nodular masses within the altered
ultramafics. Some are also found as disseminated type. These belong to
Type Podiform Chromite.
possibility of occurrences of deep-seated chromite in this belt.
Intensive searching and exploration using geophysical and drilling
inputs are necessary. Preparation for intensive search is going on and
will be completed soon.
of the important chromite deposits in Manipur are as under:
and SMS grades of limestone are found in the lensoidal bodies of
the west and in the oceanic pelagic sediment (OPS) in the
east of Ophiolite belt of Manipur in Ukhrul and Chandel districts.
Limestones are mainly massive with a few fissile at the periphery.
They occur as bouldery outcrops and bedded lensoids of varying
dimensions. These limestones can also be used in lime burning
industries. The important limestone deposits are mainly reported from
three linear melange bands in the west of Ophiolite belt in Disang
are more than 85 small limestone deposits in the ophiolite belt of
of the important limestone deposits in Manipur are as under:
occur extensively in Chandel and Ukhrul districts within the Ophiolite
Belt of Manipur extending over an area of 1100 sq.km.( about 110 km.
long and 5-15 km. wide). The belt trends NE-SW from south of Moreh in
Chandel District to north-east of Tushom in Ukhrul District up to
Nagaland border and technonically overlies the Disang sediments on its
west and is interlayered with Oceanic Pelagic Sediments.
are also commercially known as “Green Marble”. It, like granite
and marble, can be processed into monuments, tiles, slabs and other
building blocks. It is considered that Serpentinite of Manipur has a
huge market potential, both as finished products and raw forms, both
within India and outside. So far manipur is concerned, it could become
the most important mineral industry generating large scale employment
and appreciable export earning.
& Its Associated Sulphides
Arakan-Chin belt extending between the Andaman Islands and the
North-East India corresponds to a trench-arc up-thrust of the Middle
Cenozoic. Small ultramafic bodies are associated with these elongated
fold belt. The belt transects the eastern part of Manipur where it
covers an area of about 100 km by 15 km. Occurrences of chromite,
nickel, PGM and Copper Sulphides have been found along this ophiolite
belt in Myanmar, and it is highly probable that the same
mineralisations can be found in the Manipur section of the belt (BRGM-France).
The GSI has also reported presence of some PGE/PGM in some chromite
and serpentinite samples from Kwatha ,Chandel district (20
and 90 ppb) and
Phangrai (Ukhrul district). The GSI has further viewed that trace
metals like Ni, Co, V, Cu, Cr, Sr, As, Mo, Sn, Mn, Ba, Ti, Zr;
precious metals like Au, Ag, PGE (by replacing Cr, V, Ti, Al); and REE
like Ce, Ga, La could be enriched in selected locales/horizons in the
pelagic sediments. High concentration of Nickel (up to 74,000 ppm ) in
the soil above the ultramafite was indicated by the GSI in the areas
of Gamnom to Ningthi, Ukhrul District, Manipur. The geochemical
prospecting also indicated the increase in nickel concentration near
the soil-rock contact. Two sulphide mineralisations were also located
at Nampisha and Yentem ophiolite suites by the DGM. The State DGM has
initiated actions to take up the exploration at some selected blocks
in technical collaboration with the G.S.I.
western margin of Manipur constitutes a portion of basinal (geosynclinal)
part of the Assam-Arakan Oil Basin. This has been categorized by the
Ministry of Petroleum & Natural Gas, Govt. of India as belonging
to Category – I Basin (proven petroliferous basin). Sediments of
over 10 km thick and ranging in age from Upper Cretaceous to Recent is
present in the fold and thrust belt (Naga Schuppen Belt).
Eocene-Pliocene sequence contain potential source, reservoir and cap
rock. More than 40 oil and gas fields have been discovered from the