GEOLOGICAL SURVEY AND MINERAL PROSPECTING:
Present field exploration activities of the directorate since its inception can be summarized as below:
- Preliminary surveys for outlining potential of a defined mineral belt.
- Preliminary and regional surveys for outlining new mineralisations, of metallic and non metallic minerals, in virgin areas.
- Detailed surveys for blocking out grade-wise reserves, of particular mineral commodities, as promotional activity of the Directorate and similar contractual work on cost basis at the instance of public or private sector industries.
- Ad-hoc surveys for particular needs at the instance of the government.
Developments during (1955-70):
In the beginning, the Directorate started preliminary investigations and search for mineral deposits on the basis of various occurrences reported by the Geological Survey of India. The policy orientation was towards exploring relatively known industrial or non metallic mineral belts with a view to obtaining quick returns by development of these deposits at the state level. The emphasis was therefore on preliminary reconnaissance surveys for locating and developing easily accessible deposits such as clay, limestone, dolomite, gypsum, magnesite etc. Preliminary surveys were followed up by detailed mapping and sampling of these deposits and later on drilling was taken up for poring the deposits for commercial exploitation.
Activities during (1970-80):
As the expertise and confidence grew, exploration activities were diversified and more complicated problems for locating metallic deposits involving longer exploration time/ risk were taken up in early seventies. Further, with the help of United Nations development programmers, as more sophisticated equipment’s, techniques and expertise in various disciplines of geo-sciences were acquired, exploration activities ventured into virgin areas, from where prior data was virtually non-existent. Mineral exploration was now becoming basically a search for the unknown. As the easily identifiable targets were getting exhausted, greater emphasis was given to ‘concept oriented’ programmers, which demand more inputs in terms of men, material and time. This policy of looking into virgin fields with concept oriented interdisciplinary programmers has yielded results. Mineralization of scheelite associated with quartz-sericite schists in district Almora and parts of chamoli, lead and zinc mineralization with Krol formations in district Dehradun and uranium with Siwalik formations in district Dehradun/Garhwal and nearby areas were located and search for their extension was continued by the Directorate.
Activities During 1980-1990:
Most of the programmes carried out during this period were either started in the previous. Decade and continued now or follow up of the results achieved /indicated with more sophisticated technical inputs or extension of the earlier programmes. Emphasis was laid on the increase in mineral production, development of new mines/mineral deposits and setting up of new mineral based industries in the State. Search of new mineral bearing localities were taken up, based on regional surveys supplemented with programme of stream sediment geochemical survey, geophysical surveys, mineralogical studies and metallurgical testing. Simultaneously the process of estimation of quality and reserves of minerals with a higher level of confidence continued for the purposes of project development.
During this period several deposits were evaluated for quality and reserves. These included deposits of cement grade limestone, dolomite, magnesite and soapstone, pyrophyllite and diaspore, rock phosphate, silica sand, china clay, marl and kankar. Exploration work continued on the various mineralisations, to trace their continuities with an objective of converting these into mineral deposits, such work mainly related to mineralisations of copper, lead, zinc, tin, tungsten, placer gold etc. In addition investigations were carried out for the search of areas of dimensional stone in Bundelkhand and aggregate areas in the terai belt. Presence of gold was noticed at a number of localities in Lalitpur and Sonbhadra during the collection of panned concentrate of stream sediments, which were later taken up for follow up work.
Activities during 1990-2000 comprised continuation of evaluating mineral deposits and known mineralisation, while regional surveys also continued for the search of new areas of mineralization. During this period new areas of gold mineralization were found. Presence of platinum group of metals was indicated in the ultrabasic rock of Madaura, Lalitpur and potential areas for the search of diamond were investigated. Evaluation of sillimanite mineralization was also taken up.
During 2000-2005, the investigations started earlier were continued. Further studies of various geological environments in the State, for marking out the mineral associations and predicting the possible occurrences with in each type based on scientific models, are being taken up, followed by detailed exploration.