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KGCMP stands for Kachchh Geo-Chemical Mapping Project.

Objective:

National Geo-Chemical Mapping (NGCM) is an all India programme, carried out by Geological Survey of India (GSI) which will continue to run for more than 20 years until the entire surface area of the country is covered by geochemical sampling. Its main objective is in understanding the crustal growth, general geology, mineral exploration - metallogenesis - resource estimation, soil fertility – agriculture, human and animal health, establishing valid environment base line and understanding the chemistry of the environment.

Geochemical mapping can be distinguished from two similar types of Surveys, namely the geochemical exploration and geochemical prospecting. These surveys not only differ in the scale of work but also in their objectives. While Geochemical Mapping is carried out on toposheet level at a low density of sampling (1sq.km grid in case of NGCM), the other two forms are executed in smaller predefined areas 100’s of meter to 10’s of meter dimension with a much closer sampling interval. The former type of survey has wider objectives covering environment, human health and agriculture with mineralization occupying a sub-ordinate area of concern. In contrast, the latter types of surveys have mineralization as their sole bias and are usually restricted to the mineralized belts. In recent times, the most National Geological Surveys in the world have trained their attention to the societal problems including environment. Geochemical mapping has formed an important operational area where almost all the geological agencies in the developed world have devoted their resources for last two to three decades. The Chinese Geological Survey has nearly spent two decades of geochemical mapping, which has established a standard in such work. Geological Survey of India is a late starter in such systematic survey.

   The objective of Geochemical mapping is:

  1. Search of Mineral Resources;
  2. Surveys for important elements possible for human and animal health;
  3. To generate base line data of elemental dispersion to monitor and control the environment impacts;
  4. To know and devise remedial measures for geochemical, geo-environmental and ecological impacts;
  5. To identify areas suitable for agronomy and forestry and classify their types;
  6. Study of coastal dynamic processes with a view to checking the sea water incursions;
  7. To select suitable areas for aqua farming (culture);
  8. To generate base line data for situation studies for harvesting tidal energy; compositional changes of sea water for salt/brine exploration and
  9. To assess the fertility and characteristics of soil for improved and sustainable agriculture etc.

Background:

The initiative of National Geochemical Mapping has been carried out by Geological Survey of India. The Memorandum of Understanding (MOU) was entered between the Commissioner, Commissionerate of Geology and Mining, Government of Gujarat, Gandhinagar (CGM) and the Deputy Director General, Geological Survey of India, Western Region, Jaipur (GSI) in the month of April 2007. The purpose of MOU is co-operation between CGM and GSI for speedy coverage of Kachchh District, Gujarat, under the National Geochemical Mapping (NGCM) programme to complete the same within a period of 5 years. This effort is referred to as ‘Kachchh Geochemical Mapping Project’ or KGCMP for short.

In India, the GSI has launched an ambitious National Geochemical Mapping programme (MGCM) covering the entire country since field season 2001-2002 with the objective to create geochemical data base. In the course of last 5 years, GSI has developed an elaborate mechanism of Geochemical Mapping. The officers are trained, laboratories are standardized for processing of analytical data, method of storage and retrieval of data and samples have been established the methodology for processing of data and making user friendly maps have been decided and the required software have been procured. Some of the scientists have been trained in India and abroad and there is interaction with other countries doing similar work. However, owing to its multifarious activities and nation wide agendas of detailed mineral surveys and priority, GSI is able to dedicate, presently only 12 officers for NGCM in Western India (Gujarat-4 and Rajasthan-8). At this rate of coverage/ progress of NGCM work, the coverage of Gujarat is likely to take a very long time, say 50 years.

During the course of discussions between CGM and Deputy Director General & HOD, GSI, WR, it was propose to carry out Geochemical Mapping in Gujarat expeditiously in collaboration between GSI and CGM.

Guidelines:

In National Geochemical Mapping, the map represents the chemical element distribution, which is essential, harmful and passive to life. It will add an additional but very important layer to the conventional geological map.

Relevance of Geochemical mapping is well known and serves as an aid to:

Understanding the crustal growth, general geology, mineral exploration metallogenesis - resources estimation, soil fertility- agriculture, human and animal health, establishing valid environmental baseline and understanding the chemistry of the environment.

The recommended steps include:
(1) Development of methodology for sample collection and preparation
(2) Analytical reference materials and methods of analysis
(3) Data treatment and compilation.

   The basic pre-requisites are:

  • Commonly available representatives sample
  • Continuity of data across different landscapes
  • Adequate quantity of sample
  • Analytical data to cover elements of economic and environmental significance
  • Lowest possible detection limit (Clarke)

Sequentially, it should be, reconnaissance scale survey creating geochemical landscapes to be followed by regional scale mapping for geochemical provinces and then to local and detailed mapping for geochemical provinces and then to local and detailed mapping for prospecting and environmental purposes.

The country, which has a total land area of 3.28m sq.km, is yet to be mapped geochemically. Hardly 0.3%, of the land area, was mapped geochemically and that has too with a mineral exploration bias. Local and detailed scale mapping has been carried out in some areas for prospecting in identified mineralized belt and for specific environment purposes. Thus, assessment of the existing data base through:

  • Ascertaining of the commonality
  • Establishing method of normalizing
  • Collection of synthesize
  • Compilation of geochemical data as demonstration product

This project commenced in the year 2007.

 

Rapid Reserve Assessment Survey:

RRAS-I (Tertiary Limestone)

The tertiary limestone deposit occur in arculate belt, starting from east of Lakhpat (toposheet no. 41 A/9) to east of Goyla (toposheet no. 41 A/15) covering about 250 sq.km. area. This deposit runs for a strike length of 75kms with an average width of 3.5 kms. Nearly 40% of the area is occupied by Narayan Sarovar Sactuary and safe radial distance (buffer zone) for mining operations. The details of the area is as under:
Total area: 250sq.km
Mining lease area: 59.5 sq.km
Applied and recommended area for mining lease: 65.355 sq.km
Area occupied by sanctuary 49.5 sq.km
Area within radius of 2.5 km of sanctuary: 44 sq.km
Area within 1 km radius: 5.5 sq.km

RRAS-II (Jurassic Limestone)

Aim:

This project aims to identify Mesozoic limestone deposits in Kachchh district by way of mapping followed by drilling. Vast deposits of limestone occur in various horizons in Kachchh District. Most of the deposits are not explored in details. Only a part of it has been investigated by erstwhile Director of Geology & Mining (CGM) during 1964-67, which covered the Tertiary Limestone belt of Western Kachchh. The investigation was for detailed exploration by pitting & trenching. However there are good limestone deposits confined to Jurassic rocks in the islands & North of Bhuj & Tertiary (Miocene to Oligocene) in the area. Geological survey of india has investigated a a\small part of the area in the part of Kala Dungar by pitting, trenching and large scale mapping. This investigation has suggested a possibility of large scale deposits of Chemical, SMS & BF grade limestone in parts of Kala Dungar. With increase in demand for limestone for cement & chemical industries it is necessary to access grades & reserves of limestone area in different geological horizon in different parts of Kachchh is to the tone of 12959 million tons qualitatively..

Status:

Mapping has been completed for 179.5 sq.km area in north western, eastern and southern sides of Bhuj. The mapping being carried out at present in specialized Thematic Mapping (STM) on 1:25000 scale, which is ideal for locating new mineral deposits. The STM mapping is being carried out with the help of IRS 1-D LISS 3 and PAN hybrid satellite imagery having very high ground resolution of 5.8 meters. This ensures a very high accuracy of the interpreted data which can also be enlarged to larger scales for planning of borehole locations with high accuracy.

The geological map of the area brought out structural details of limestones bearing Pachchham and Chari Formations in the north western, eastern and southern side of bhuj town. Most of these limestone deposits fall within Reserves Forest area and can not be mined. The quality of the remaining limestone deposit occurring outside RF area is very poor as indicated by sampling results.

Currently, STM mapping is being carried out in Bhachau- Samkhiyari- Rapar areas.

Area mapped since January 2010: 115 sq.km.