PHYSICAL FEATURES AND NATURAL RESOURCES

ECONOMIC GEOLOGY

 Bauxite.

Amboli-ghat deposits.—Two parallel ridges, situated at the trijunction of Belgaum, Kolhapur and Sawantwadi contain bauxite associated with laterite which varies from 50-100 feet in thickness. The slopes of the ridges are sometimes strewn with float ore. Two important float ore deposits are confined to the north and north-west of the western ridge, the average thickness being 2 feet. The western ridge is capped by a more massive bauxite. The laterite on both the ridges in general, is aluminous, with lens-shaped patches of grey bauxite of good quality. The massive cliff of the western ridge shows several such patches along the length of the ridge. It is estimated that about 40,00,000 tons of bauxite will be available in the western ridge and about 9,80,000 tons in the eastern ridge. The float-ore may be of the order of 2,00,000 tons. The analysis of samples gave the following range in composition:—

The extensive spread of laterite in the lowlands of the Ratnagiri district is in general, devoid of bauxite. The laterite, however, appears bauxitic at a few places along the coast near Harnai, Vijayadurg and Deogad. At Harnai, a wall-like scrap of the laterite shows concentrations of white gibbsitic matter. The quantity is considerable, and being so close to the sea, has possibilities of exploitation in the near future. The whitish portion of the laterite on chemical analysis, gave the following result:—

Building Stones.

The district is well endowed with various kinds of rock suitable for building construction. These comprise granite-gneiss, basic dykes, quartzites, Deccan trap and laterite. Being very hard, the granite-gneiss is only locally worked near Sawantwadi, Banda, Kadwal, and Avlegaon. Basic dykes are locally quarried for building purposes and also as a road metal near Banda, Dagve, Sawantwadi and Kankavli. Hard, compact, fine to medium-grained Kaladgi sandstones and quartzites are quarried for dimension blocks near Phonda, Golvan, Katta, Trimbak, Shravan, Achra and Math. Deccan trap covers a large portion of the district and can be easily quarried. It is therefore, quarried both for dimension blocks and as a road metal near Ratnagiri, Chiplun, Kharepatan, Rajapur, Talera, Nagwa, Tarndala, Januali and along the Kasal-Kankavli road. Laterite has a peculiar property of being soft when newly quarried and becoming hard and compact on exposure to the air. This facilitates the easy quarrying and is therefore worked out locally for dimension blocks all along the coastal tract in the district.

Clays.

There are no known good deposits of China clay in the district. However, a few small pockets of China clay, formed due to the decomposition of the feldspars in the granite, are noticed in the gneissic country. One such small occurrence is to the south of Kurnbharmath east of the Malvan port. The kaolin is of good quality and is slightly plastic. It does not fuse at 1,200° C and burns white.

Deposits of red, plastic, lime free, lateritic clay suitable for the manufacture of cheap and glazed-wares and roofing tiles are noticed on banks of a nala below an overburden of 5 to 12 feet north of Jalgaon, in the Dapoli taluka. The sample analysis is as follows: —

Chromite.

Chromite deposits of the district are located in the valley of the Gad river, one mile north-north-east of Kankavli and near Vagda. The ore body is associated with an intrusive body of serpentine intersecting the foliation of Pre-Cambrian gneisses and schists. It is about half a mile long and varies from six to thirty feet in width. The ore is in the form of grains disseminated in serpentine and chlorite. The reserves of chromite ore are estimated at 50,000 tons in the Kankavli deposit and about 17,000 tons in the three small loads near Vagda. Chemical analysis of a few samples of the ore gave the following results:—

The chromite deposits could not be marketed owing to the high iron content; eventually, with the availability of cheap electrical energy, and some suitable methods of beneficiation, these deposits may be worked at a later date, for use in chemical industries.

Feldspar.

Potash feldspar occurs as a major constituent mineral of the micapegmatite near Kadawal. The feldspar is quite suitable for the use in the ceramic industry and can be recovered as a by-product during mica mining.

Glass Sand.

Some of the sandstone beds of the Kaladgi Series are used in glass making and are exposed on the Sawantwadi-Vengurla road, at Maldi, Vetora and at Valaval. These sandstones which strike N.W.-S.E. dipping almost vertically towards north-east vary in thickness from 10 to 50 feet. The deposits at Valaval and Vetora are estimated to contain roughly seven million and fourteen million tons, respectively, but the material is not likely to be of uniformly good grade.

Pinkish, soft sandstones, which can easily be crushed are noticed one mile west of Math. The rock is locally used in the manufacture of sodium silicate in a factory near Vengurla. White, sacharoidal, fine-grained, highly friable sandstones found below a thin laterite-cap near Kumbrol appear suitable for glass manufacture. Similar deposits of sand are also worked near Chendvan, Tendoli, Dabholi, Achra and Mithbav. The analysis of few samples from above localities gave the following results:—

All the deposits are worked on a small scale and the material is shipped to Bombay for glass manufacture. The demand so far, has been for sand powder crushed to about 10 meshsize, and the cost per ton delivered to Bombay, works to about Rs. 30.

Ilmenite.

Beach sands containing ilmenite-sand occur sporadically along a 25-mile long coastal belt from Purangadh to Malgund and beyond, the thickness of the ilmenite-sand varying from a minute fraction of an inch to a maximum of three feet. The thickness of the coastal sand, inclusive of the sand dunes, cannot be more as the underlying laterite or trap is visible in a number of localities. The accumulation of ilmenite-sand is attributed to wave or wind sorting on the slopes of the sea shore. The reserves near Rajwade, Bhatya, Ratnagiri, Purangadh, Gaonkhadi and Malgund are supposed to be quite extensive. The TiO₂ content varies from 28 to 52 per cent. while the ilmenite content varies from 25 to 76 per cent.

The deposits of ilmenite-sand along the Ratnagiri coast do not compare in any way with the rich and extensive deposits of Travan-core, though they do contain some of the important minerals such as monazite, zircon, etc., to a certain extent. However, there are a few good workable deposits which could be exploited for marketing, particularly after improving the grade of sand by processing.

Iron-ore.

Two types of iron-ores are noticed in the southern part of the district, viz., the banded-hematite-quartzite and the lateritic iron-ore. Small bands of banded-hematite-quartzite are noticed along the coast near Aravli, Aros, Satarda, Tiravada, Ajgaon and at Redi. At present, the ore is worked at Redi. Randed-hematite-quartzite underlying about 25 feet thick laterite, form the source of the iron-ore in the one and a half mile long, low-lying hills, facing the Arabian sea, south of Redi. The rock shows a variation in dip from N 10°E to N 30°E at 40 to 60 degrees. A number of quarries are worked to a depth of about 35 to 40 feet. The ore bodies form a series of discontinuous lenses of varying grades. Roth massive and powdery ore has been found. The lenticular ore bodies show a tendency to peter out and give rise to soft powdery ore at either end, and similar powdery ore is also encountered at depth. Therefore, the available reserves of high grade ore, carrying more than 62 per cent. iron, are limited, and there is a greater proportion of the ore carrying between 58 and 60 per cent. of iron. The reserves of all grades are quite extensive.

Highly ferruginous laterite forms the lateritic iron-ore and is found at a number of places in the district near Asoli, Khanavli, Kochra, Mahapan, Pat, Parule, Dhampur, Kalse, Amberi, Danoli, Otavane, Aravali, Aros, Satarda, Tiravada and Ajgaon. A good quality laterite iron ore analyses to little above 50 per cent. Almost inexhaustible quantities of the ore will be available along the coast in the district.

Limestone.

No extensive deposit of limestone has so far been found in the district. However, boulders of light to dark and purpish-grey, massive, concretionery limestone, exhibiting a pseudo-oolitic structure, is noticed in the valley two miles north-east of Talera. The limestone is associated with the Kaladgi shales and is supposed to be of metasomatic origin. The deposit is not very extensive. This lime was used for construction of the dam at Radhanagari in the Kolhapur district.

Chemical analysis of a few samples gave the following results:—

Manganese.ore.

Deposits of manganese-ore are reported to oecur in the southern parts of the district and are occasionally worked in the Sawantwadi taluka only. Manganese occurs as irregular boulders in the laterite or replacements of ferruginous matter in the Dharwar phyllites and quartzites. The ore, in general, is of low-grade and is noticed near Banda, Degve, Adali, Kalne, Phondye, Sasoli, Netarde, Dingne, Galel, Dongarpal, Panturli and near Talavadi. The deposits at Banda, Kalne, Sasoli, Phondye, Dingne and Galel, though not very promising, could be worked in the event of a demand or boom in the manganese market.

A pegmatite intruding the biotite-schists and the granite-gneiss near Kadawal about 12 miles north-east of Kudal, carries mica in the form of books. The pegmatite is about 1,600 feet in length and 600 feet in width. The mica is colourless or greenish to grey in colour, occasionally stained and spotted. It is at times buckled and appears wavy. Ruby variety is also reported to have been found. Sizes 3 and 2 are common but sizes 1 and A1, though rare, are also reported to occur at depths.

Mineral Waters.

Hot springs are found in various parts of the district. They occur along a line half way between the Sahyadri hills and the sea, along the eastern margin of the coastal region. Some of the important group of springs are as follows:—

1. Khed Springs.—These are approachable by road from Bombay and Poona, distance being 176 miles and 104 miles, respectively.The springs give plenty of bubbles of carbon-di-oxide and hydrogen sulphide. The rate of flow is about 140 gallons per hour. The temperature is about 35.5°C. The radons m.Mc. per litre is almost nil. The water is reputed to cure skin diseases and rheumatic complaints.

2. Unhala Springs.—-These are situated south of Unhala villagein a marshy land, at a distance of about 12 miles from Dabhol wharf. The springs yield plenty of bubbles of hydrogen sulphide and carbon-di-oxide. The rate of flow is about 1,500 gallons per hour. The temperature is 69°C and radons m.Mc. per litre is O.806. The springs are reputed to cure skin diseases and rheumatic complaints. The water is reported to be a good appetiser. It contains chloride and the water is saline.

3. Aravali Springs.—These are situated south of the Gad river bridge in the village Aravali about 20 miles from Chipun. The springs give out plenty of bubbles of carbon-di-oxide and hydrogon sulphide. The rate of flow is about 916 gallons per hour. The temperature is 40°C and the radon content m.Mc. per litre is nil. The springs are also reputed to cure skin diseases.

4. Tural Spring.—This group of springs is situated to the east of the road between Chiplun and Sangameshwar. It gives out plenty of bubbles of carbon-di-oxide and hydrogen sulphide. The rate of flow is about 1,000 gallons per hour. The tempera ture is about 61°C. The radon content m.Mc. per litre, is nil and the water is reputed to cure skin diseases.

5. Rajwadi Spring.—It is situated to the south of Rajwadi village, about a mile east of Chiplun-Sangameshwar road and can be reached from Karad Station via Chiplun. The spring gives out plenty of bubbles of carbon-di-oxide and hydrogen sulphide. The rate of flow is 1,870 gallons per hour. The temperature is, 54°C. The spring is also reputed to cure skin diseases and rheumatic complaints and also as a good appetiser.

6. Sangameshwar Spring.—Occurs in the bed of the Shastri river about 1½ miles from Sangameshwar town and lies submerged throughout the year. The spring gives plenty of bubbles of carbon-di-oxide. The temperature varies from 50°C to 60°C, and is known to cure skin diseases.

7. Rajapur Springs.—Occur on the southern bank of the tidal river in the Unhala village near Rajapur. The temperature is about 42°C and is known to cure skin diseases and rheumatic complaints.

Ochres.

Small deposits of various coloured earths, viz., yellow, red, black, brown, chocolate, green and rakhi, are reported to occur near Degwe, Dongarpal, Amboli, Morgaon, Sarambale, Sasoli, Phondye, Mandkol, Ralkot, Katta, Golvan, Pat, Parule and a number of other places in the hills along the coast between Malvan and Vengurla. The ochres are shipped to Bombay for the manufacture of mineral pigments.

Salt.

Salt is recovered by the direct solar evaporation of sea water along the Ratnagiri coast near Ratnagiri, Malvan, Vengurla and Shiroda. Tne annual total production is about 45,000 Bengali maunds. The major portion, however, is produced near Shiroda which is of the odrer of 40,000 Bengali maunds, annually.

Steatite.

Small bands of dark grey-grained, soft steatite are noticed near Asgani about ten miles east of Malvan, near Akheri, Jholamba and in the hills between Kumbrol and Panturli. They are worked out locally for making utensils, etc., but are not likely to support a flourishing industry.

Water-supply.

As regards the water supply, the district may be broadly divided lengthwise into five belts: (1) the sea-coast, (2) an inland belt of laterite, eight or ten miles broad, (3) a ten-mile belt of mixed laterite and basalt, (4) a belt of basalt, six to eight miles wide and (5) the foot of the Sahyadri hills.

The villages along the sea coast are supplied with drinking water from wells generally fed by sea filtering through the sand. The supply is abundant, almost every house in the village having its own well. The laterite belt is supplied with drinking water partly from wells and partly form the hills side springs. The third, laterite belt is supplied with drinking water from wells fed by running springs in a few cases. The supply is both abundant and wholesome. In the basalt bed the water supply is scanty and bad. The villages in the fifth belt, immediately at the foot of the Sahyadri hills have in many places good wells. However, the manner of occurrence of underground water changes from place to place owing to the diversified character of the water bearing formation and variations in the geological structure. The metamorphic rocks hold very little underground water and the villages situated on these rocks have only a few wells and have to depend for drinking water on springs from faces of the overhanging hills of the Sahyadris. The Kaladgi rocks crop out as isolated patches surrounded by trap and laterite. The rocks which are well cemented are useless as water containers but a few sands and silts which have escaped cementation, serve as reservoirs of underground water.

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