192 NEWS AND NOTES Bangalore; Corporation Bank and State Bank of India. A Glimpse on the Importance of the Coastal Zone, its Problems and Suggestions for their Management – Tapas Kumar near coastal area occur as reworked deposits behavior and effect of mining. It may not be in medium to high energy environments and difficult to achieve the optimum target of Mallik, Former Director, G.S.I., used for construction purpose. During the exploitation without any harmful effect on FD-317, Sector III, Salt Lake, high tide in the coastal areas near the the islands. Kolkata – 700106 offshore banks the barges are floated. They Heavy mineral placers are deposits of Why Study the Coastal Zone? settle when the water recedes during low high specific gravity, resistant minerals Earth’s history is linked with the coastal tide and the sand and gravel are loaded in the associated with beaches, rivers, dunes and zone and the sea. Through the coastal tracts barges. This venture can be attempted within shallow offshore areas formed by the the Sea is receiving sediments which records a limited distance from the coast. process of mechanical concentration due to the history of geological events. Society Shells, corals and calcareous sands weathering, transportation and deposition depends on the coastal zone for its bio- occurring in coastal areas have been used in suitable locations. Important concen- logical diversity, mineral resources, for for manufacture of cement. They are utilised trations of these minerals occur in beaches, fulfilling recreational opportunities, for on a small scale from early historical times sand dunes, buried channels, shallow sustaining important industries, for waste for whitening, making lime and for local offshore areas, back waters and also in the disposal, transportation and also reflects the construction. The best known deposits are relict sand bodies. Commonly occurring modification of climate. There is a massive in the Gulf of Kutch and in Vembanad Lake, placer minerals are magnetite, ilmenite, increase in population living in this zone. Kerala. monazite, zircon, columbite, cassiterite, Lots of problem arises due to storm damage, The Lakshadweep are a group of least scheelite, wolframite etc. These deposits sea level rise, coastal erosion and silting. studied coral atoll enclosing lagoons, occur in the form of lenses, stringers, and Also there are many conflicts in this zone submerged reefs and banks situated in the beds up to 3 m thick. Sorting takes place and an efficient management is necessary Arabian Sea at a distance of 200-300 km during transportation according to size, for sustainable development of the coastal from the West Coast of India.. There are 11 shape and specific gravity of the minerals resources. major islands and lagoons (Kavaratti, and controlled by the processes as currents, Study of the Coastal Zone started in Kalpeni, Agatti, Chetlat, Bitra, Kiltan, waves, sea level changes etc. The jigging 1726 with Hutton’s study on sea level Kadmat, Amini, Bangaram, Suheli, action of waves and surf tends to concentrate changes and observations on lands. Minicoy) and 4 submerged reefs (Beliapani, the heavy minerals in certain zones in the Subsequently, a number of workers carried Cheriapani, Perumalpar, Androth) and 5 beaches and also in the submerged areas out different types of work in the coastal banks (Bassas de Pedro, Sessostris, formed during the Pleistocene when the sea zone specially on the beaches. In 1851,GSI Coradivh, Aminipitti, Elikalpeni). level was much below the present level. was set up for Geological Mapping, Mineral The calcareous sands are derived from Vast deposits of placer minerals occur Exploration and studies related to coasts. different varieties of corals which occur in in the stretches of coastal areas of Kerala, The amount of elevation of coasts was the lagoons and reef areas. The Exploration Tamil Nadu, Andhra Pradesh, Maharashtra, determined from study of raised oyster and Survey by GSI indicated the occurrence Orissa and in selected sectors of West banks, submerged forests of Bombay of 288 million tonnes of calcareous sands Bengal. At present the industry is being Island.and Smooth Water Anchorage on in the lagoons to a depth of about 1 meter dominated by IRE which accounts for 95% Mudbanks off Kerala were also studied. below the lagoon floor. The inferred output. Mining will always require EIA Continental Drift Theory was established by reserves are about 712 million tonnes. These study. Extensive dune sand deposits occur fitting the coast line. In1954, Professor La sands are of good quality with a high in Orissa coast and mined by OSCOM. Fond visited Andhra University and percentage of CaO and low amount of Ilmenite, zircon, monazite, garnet, different types of work were carried out on silica, alumina and iron . MgO appears only sillimanite are mined in Chatrapur, Orissa the coastal zone. as impurity. The most important sediment along a coastal belt of 18 km and an area of Resources of coastal zone are forming site is the reef area and it should 26 sq km. 230 million tonnes of raw sand renewable and work can be continued for a not be disturbed as far as possible. The contains 20-25% heavy minerals. A number long time. Extraction of salt from the coastal lagoon is the most important accumulation of new products have been developed here zone is known from ancient times and is site and it will have the tendency to fill up in addition to rare earth chlorides, fluorides, still being done. The resources of the coastal automatically if the sands are taken out. oxides, calcium oxide, hydrates etc. Ilmenite Mining can even be started in one of the (FeO TiO ) and Rutile (TiO ) are the main zone are derived from land or they might 2 2 have been formed by biogenic processes. uninhabited island with simultaneous Sources of Ti. Sands, gravels and aggregate from the studies on bathymetric, organic community, India is 4th largest after Mozambique, shoreline changes etc., to understand the Australia and China. Ti is used for aerospace JOUR.GEOL.SOC.INDIA, VOL.78,AUGUST 2011 NEWS AND NOTES 193 applications, medical, automobile and management programme was thought absorbing and reducing the impact of jewellary. In India reserve of Ilmenite is leading to the formation of coastal strong winds, tidal waves and floods that 161 million tonnes. (Tamil Nadu 31%, A.P. regulation act which was notified by the usually accompany the tropical states. 30%, Kerala 26% and Orissa 13%). World Ministry of Environment and Forest in India They should be studied and preserved reserve of rutile is 155 tonnes. India is in 1991. carefully. second after Australia. Segmented use of The Coastal Regulation Act prohibited 5. There is an urgent need for evolving Ilmenite includes Paint s 57%, Plastic 22%, many activities like setting up of New integrated national Earth science Policy Paper 12%, Others 9%. Titanium metal is industries, suitable mechanism of waste and role of National Agencies. Close used for making artificial hips, knees, heart disposal etc. Permissible activities include interactions with scientists of different valves, dental works etc. Aerospace Industry construction for defence, ports, harbour, disciplines will help in achieving our has the single largest market for Ti products light houses, thermal power plants etc. target. due to its exceptional strength . In addition 6 There should be a proper mode for data the metal is also used for jewellary, eye Important issues for consideration in dispersal. glass, watches etc. Garent is mined by the Coast Zone 7 Detail studies and likely impact of Indian Ocean Garnet, mine site is located 1. Our first objective will be to solve societal mining on various aspects of environ- NE of Kanyakumari. Blasting grade garnet problems like coastal erosion, ment and ecology has to be covered ( 0.7 to 1.4 m) used for cleaning of ships, earthquake hazard, tsunami effect, before large areas are mined. oil rigs, oil pipes, vessels boilers etc. Water pollution etc. Climate changes are 9 Stabilisation and conservation of dunes Jet cutting grades (0.42 to 0.25 mm) is used bound to occur due to human induced and formation of neo-dunes by artificial for cutting stainless steel, titanium alloys, accumulation of carbon dioxide, nitrous methods should be attempted. granites, glasses etc. Almandite is the best oxide and methane which are increasing 10 Improved coastal protection measures abrasive garnet. and causing higher global temperature. like construction of seawalls, offshore leading to melting of ice causing sea submerged breakwaters, shore walls Coastal Zone Management level rise and more erosion of the coast beyond high tide line, tsunami mounds The coastal lands are thickly populated justifying a close monitoring of the etc. should be carefully designed. Coastal waters are most productive. beaches. The effect on inter tidal Constant watch on artificial structures Episodic physical events like tsunami, wetlands, coastal dunes should be and their maintenance should be hurricanes, algal blooms etc are common monitored by satellite imageries and followed. in coastal zones. Global climatic change, field traverse at regular intervals. 11 Infrastructural development for tourism seal level rise, coastal erosion and the 2. We have to concentrate on placer and in the sea coast sites for fisheries, fish changing weather pattern is characteristic calcareous sand deposits along the farming human settlement is to be of coastal region. Conflicts from tourism coasts. considered carefully. and fishing is common. Development 3. Infrastructure should be developed with 12 Much importance has to be given on activities without considering the delicate reference to instrument, manpower, studies on special aspects like ecosystem have invited a number of public awareness and education. Proper ichnological studies or study of coastal problems. The manmade causes include attention should be given for the cells. Study of trace fossils in recent interruption in the sediment transport, essential support needs like education, sediments and in delta areas gives reduction in sediment supply, sand mining.