GEOMORPHOLOGY , GEOLOGY AND MINERAL RESOURCES
State of Environment Report of Tripura for the year of 2002
Geomorphology, Geology and Mineral Resources

 

2.0 Geomorphology

Geomorphologically, the state of Tripura represents the western fringe of typical “ridge and valley” province of the late Tertiary fold mountain belt, commonly known as Indo-Burman ranges (Purbanchal range). The general elevation varies between 780 m in the north eastern part to 15 m in the western part above mean sea level. Five prominent roughly north south trending anticlinal strike ridges traverse the state from east to west; these are Jampui, Sakhantlang, Longtarai, Athramura and Baramura. This strike ridges form the watershed of the Meghna basin of Bangladesh fed by Khowai, Haora, Juri, Manu, Dhalai, Deo, Longai, Muhuri, Feni and Gomoti rivers. Ten physiographic units have been identified by the Geological Survey of India (1999) in the State of Tripura which are given below Table-11.

Table-11 : Physiographic unit of Tripura

      i.         

Steeping slopping and slightly dissected high relief structural hills and ridges exemplified by areas like Kailashahar, Panisagar, Baramura, Teliamura, etc.

     ii.         

Moderately slopping with moderately dissected medium relief parallel ridges present in north and north eastern part of Tripura.

   iii.         

Moderately slopping and highly dissected, low relief structural hills and ridges found in the north-west and southern part of the state.

   iv.         

Moderately to gently slopping and moderately dissected flat topped denuded hill occurring in western, central and southern part of Tripura.

    v.         

Low lying residual hill with valley represented by Gonda charra area of south eastern part of Tripura.

   vi.         

Undulatory plain with low mounds and gently slopping valley situated mostly in the western and southern part of Tripura.

 vii.         

Moderately to gently slopping inter-hill valley with upland mostly occurring on the northern- eastern and southern part of the state.

viii.         

Moderately to gently slopping inter-hill valleys with alluvial upland plains, represented by Kumarghat-Chailengta area as alluvial deposit of river Manu.

   ix.         

Rolling upland common in some pockets of the west and north-western part of Tripura.

    x.         

Flood plain constitute important area rornled by rivers of Tripura. Studied area Krishnakishore nagar and Jampuri fall under this group.

[Source: Mukherjee, Bhatacharrya and Sribastav, GSI, 1999]

2.1 Geology

The state of Tripura exhibit an wide array of sedimentary rocks characteristics of marine-mixed-fluvia type origin ranging age from upper most Oligocene (38 million years from present time) to Recent period. These sediments, according to GSI, have been laid down in the Surma basin during Tertiary age (which lasted for 65 million years) in an wide range of environmental conditions governed by local tectonic movement. Tectonically, the region now comprises a series of sub-parallel arquate, elongated, doubly plunging folds arrange in north south direction. These folds for anticlines separated by wide flat sinclines.

The group of sediments during different geological age are shown in Table-12 on litho-stratigraphy.

Table-12 : Stratigraphy of Tripura

Age

Group

Formation

Holocene

 

Khowai Formation Ghilatoli Formation Teliamura Formation Kalyanpur Formation

Quaternary

Dupitila

Dupitila Formation

Upper Pliocene to Pleistocene

 

Pliocene

Tipam

Upper Tipam Formation

Lower Tipam Formation

 

Micocene- Lr. Pliocene

 

 

Upper most Oligocene

 

Surma

Bokabil Formation

Upper Bhuban Formation

Middle Bhuban Formation

Lower Bhuban Formation (Not exposed in Tripura)

Seismic surveys in the region reveal the presence of sub-surface flatus. The part of Surma basin in Tripura Mizoram area lies in close proximity to the Shillong plateau in the north and Aracan Yoma belt to the east. Tripura is therefore located in seismically active zone; because of inherent character of sediments of these areas even the minor shock during earthquake may cause devastating particularly landslides (Mukherjee et.al., GSI, 1999)

 2.2 Mineral Resources

The mineral resources of any state provide an avenue for economic development but the process of mining may have extensive impact on land, soil and water resources. The mining projects have as a consequence become a part of development sector requiring environmental clearance under Environmental Protection Act, 1986, EIA Notification 1994

In Tripura, the mineral resources are mainly glass sands, limestone, plastic clay and hard rock; all of these material are being used to a variable degree. However, the single most important resource in the state is oil and natural gas. ONGC or Oil and Natural Gas Commission has initiated massive exploration programme in the State, details of which are dealt later.

As for the other minerals, Table-13 provides an account of locations, deposit, current uses, etc. Details of clay deposit in Tripura has been dealt in the State of Environment Report for Tripura (1989). The impact of mining and quarrying of mineral resources in Tripura has so far been insignificant.

Table- 13 : Mineral Resource of Tripura

 

Mineral

Location

Uses

Hard Rock

Jampui Hills

Longatari Hill

Road metals

Limestone

Sakhan & Jampui Range

Manpui area

(990,000 t. reserve)

Not suitable Cement

Suitable for inferior quality of Lime Puzzolana mix.

Clay

All over the State generally in river bank deposit

Good clay deposit in West and South region.

Total 1.73 million ton deposit in four zone out of six zones*

[* Mohanpur-Bamutia-Kamalghat;  Bisramganj-Bagma; Champamura-Baldakhal-Jogendranagar; Khowai-Teliamura-Ampi; Shantirbazar-Udaipur; Kumarghat and Baidyathakurpara- Anadanagar- Maheshkhola-Dukli-Sonamura area]

Sanitary ware

Stone wares

Sewerage pipes

Electric insulator

Refractory grade

 

Glass Sand

Bishramganj (160,000t)

Old Agartala (16,000t)

Jogendranagar (3627t)

Sekerkota (80,000t)

Dasharambari (5330t)

Mohanpur (97,875t)

Baidyathakurpara- Anadanagar Maheshkhola and Dukli (NA)

Total Reserve 3,62,832 tonnes

Many uses

[Source: GSI Report 1982, 1999]

Of the total geographical area of Tripura, 76% can be marked as of “Tertiary” origin and 24% belong to Quaternary period; none of these contain any major mineral resource. A GSI Report of 1982 provide a list of Non-metallic and metallic mineral vis-a-vis their location or otherwise in Tripura (Table-14) indicating the poor profile.

Table-14 : Mineral Resource potential in Tripura

 

Sl. No.

Mineral

Status

A.

Non-metallic

1.       

Lime stone

Commodity not located or absent

2.       

Dolomite

Commodity not located or absent

3.       

Coal

Commodity not located or absent

4.       

Clay

Commodity not located or absent

5.       

Refractories

Commodity not located or absent

6.       

Glass sand

Good reserve, low grade

7.       

Graphite

Commodity not located or absent

8.       

Fertilizer

Commodity not located or absent

9.       

Gravel sand silt

Good reserve, low grade

10.   

Building stone

Commodity not located or absent

B.

Metallic

11.   

Ferrous

Commodity not located or absent

12.   

Non-ferrous

Commodity not located or absent

13.   

Noble metals

Commodity not located or absent

[Source: GSI Report 1982]

The current production of natural gas in estimated at one million cubic meters per day. The available figure for 1990-91 to 1997-98 shows a fast increasing rate of production from 70 million tonnes per year in 1990-91 to 2.7x in 8 years reaching 196 million tonnes in 1997-98.

 

 
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