Chamoli, carved as a seperate revenue district in 1960 out of the erstwhile Grahwal district, lies in the Central Himalya and constitutes a part of the celebrated ‘Kedar Kshetra’.The District Chamoli is surrounded by Uttarkashi in North-West, Pithoragarh in South-West,Almora in South East,Rudraprayag in South-West and Tehri Grahwal in West. The geographical area of the District is around 7520 sq.kms.
Geology
The geology of the region shows that the Himalayas are the young mountains in the world. During early Mesozoic times, or the secondary geological period, the land mass now covered by them was occupied by the great geosynclinal Tethys sea . The probable date of the commencement of the elevation of the Himalayas is about the close of the Mesozoic period, but the unraveling of the story of their structure has only just begin, and in many cases no dating of the rocks is yet possible, though they include ancient and relatively recent crystalline intrusive, rocks and sediments allied to the peninsular part of India . The section of the range in the district is deeply cut into by the headwaters of the Allaknanda river, this trunk stream seeming to have reached a latter stage of development than its tributaries. This much, however, is known that there has been intense metamorphosis. In some parts uplift has been considerable since the mid-pleistocene period, in others there are great stretches of high but subdued topography and elsewhere there are the deepest gorges. The direction of folding in these mountain masses is generally North to South. The geological feature of the district form two major divisions which lies North and South of an imaginary line extending East-South- East between the villages of Hilang in Joshimath and Loharkhet in the adjoining District of Pithoragarh. The Northern division, which is occupied by higher ranges and snow covered peaks consist entirely of medium to high grade metamorphic rocks and is intruded by later volcanic rocks. The Division to the South, occupied by ranges of lower altitude, consists essentially of sedimentary and low grade metamorphic rock also intruded by later volcanic rocks. Geologically very little is known of the first division which consists of rocks such as quartzites, marbles and various types of micaceous schists and gneisses which a few sporadic occurrences of garnet, graphite, iron, kynite, mica and vein quartz. The division to the south of the imaginary line is better known geologically and consists of rocks such as gneisses, limestone, phyllites , quartzite, sericite-biotite schists and slates.
Minerals
The minerals that are found in the district are the following-
Asbestos
This is of the amosite variety and can be used for the production of asbestos, cement bricks, laboratory asbestos sheet and paper, but is not considered to be of economic importance.
Magnestic – This is of an average quality is crystalline in nature, and is found associated with crystalline dolomites and sometimes with soapstone. The Magnesium carbonate found here is also of average quality and its mineralisation has also been reported to occur in the district.
Soapstone or Steatite – This white saponaceous stone resembling pipe clay is obtained in as lenticular body and is associated with mineral pyrites, which adds a color to it, and in places with magnesite. it can be mined for use as filler in soap and in the cosmetic industries. In the past various utensils were made of it which, when polished, had the appearance of marble.
Copper – The copper mines in the district are extensive and of reputed during the period of Hindus and The Gorkhas rules. All the rich mines have since being exhausted and at present they do not offer a fair field for the employment of capital.
Iron – Small and sporadic occurrence of iron are known to occur in several parts of district but are of hardly any economic important. Iron ore, rich in haematite, and magnetic ore, with haematite and siderite, also occur in the district.
Graphite – In the past this mineral, also known as plumbago, found mostly in patti Lohba, was used as a dye but no large deposits have been noticed for a long time.
Gold – Although no gold mines has been discovered in the district, the sands of Alaknanda and the Pinddar are said to be auriferous to a limited extent.
Gypsum – This mineral is found on the bank of some river and was used in the past for the manufacture of saucers and bowls .when ground to a fine powder it is known as Plaster of Paris and can be used for a number of purposes.
Lead – Deposits of this metal were fairly numerous in the past but it is found in somewhat inaccessible places and has long since ceased to be worked.
Slate – This dense, fine grained metamorphic rock, which is produced from a fine clay, can be split into thin, smooth plates and is quarried throughout the district. It is suitable for roofing purposes, the thin dark blue slates being somewhat inferior in quality.
Limestone – By burning this mineral, lime is procured which can be used as mortar. There are two distinct ranges of lime stone hills in the district, the first, north of the Alaknanda in Nagpur, the second, running from Lohba patti to the Pinddar and again to the Alaknanda in patti Bacchansyun in district Garhwal. Reserves of dolomite exists in the district and tufaceous deposits are also found near several Nullahs.
Building Stone – Stone which can be used for building purposes is available in most parts of the district. Sand stone is found in abundance in the lower hills. Gneiss and chlorite schists which are available throughout the district are frequently used for building purposes.
Sulphur – This yellow mineral, also known as brimstone is found in the district as green sulphate of iron and is obtainable from iron pyrites and copper mines, its presence being characterised by a small as of rotten eggs. Sulphur springs also occur in many parts in the district.
Bitumen – The brownish white natural sulphate of alumina known as Shilajit is found in rocks at a fairly high altitude and occur in small lumps which generally have an admixture of red sand and micaceous stone embedded in them. It is used in Ayurvedic medicine and during the season when there is an influx of pilgrims, it fetches good income to those who deal in it.
Some other minerals found in the district are Antimony, Arsenic, Lignite or Brown Marble, Mica and silver.
Physiographically the district, which lies in a region of tectonic or folded and overthrust mountain chains, has strata are structurally marked by complex folds, reverse faults, overthrusts and nappes of great dimensions, all these as well as frequent earthquake of varying intensity give region to believe that the region is still unstable. Although any movement or tremor of the earths crust in the district is not produced by volcanic activity, the Chaukhamba peak a pair to be the crater of an extinct volcano.
CLIMATE
As the elevation of the district ranges from 800 mts. to 8000 mts above see level the climate of the district very largely depend on altitude. The winter season is from about mid November to March. As most of the region is situated on the southern slops of the outer Himalayas, monsoon currents can enter through the valley, the rainfall being heaviest in the monsoon from June to September.
Rainfall – Most of the rainfall occur during the period June to September when 70 to 80 percent of the annual precipitation is accounted for in the southern half of the district and 55 to 65 percent in the northern half. The effectiveness of the rains is, among others, related to low temperature which means less evapo-transpiration and forest or vegetation cover. However, the effectiveness is neither uniform nor even positive in areas where either the vegetational cover is poor or / and has steep slops or the soils have been so denuded that their moisture absorption capacity has become marginal.
Rain gauging stations put up at seven locations by Meteorological department of Govt. of India, represent the settled land mass of Chamoli district.
Temperature – The details of temperature recorded at the meteorological observatories in the district show that the highest temperature was 340C and lowest 00C. January is the coldest month after which the temperature begin to rise till June or July. temperature vary with elevation. During the winter cold waves in the wake of western disturbances may cause temperature to fall appreciably. Snow accumulation in valleys is considerable.
Humidity – The relative humidity is high during monsoon season, generally exceeding 70% on the average. The driest part of the year is the pre monsoon period when the humidity may drop to 35% during the afternoon. During the winter months humidity increases toward the afternoon at certain high stations.
Cloudiness – Skies are heavily clouded during the monsoon months and for short spells when the region is affected by the passage of western disturbances. During the rest of the year the skies are generally clear to lightly clouded.
Winds – Owing to the nature of terrain local affect are pronounced and when the general prevailing winds not too strong to mask these effect, there is a tendency for diurnal reversal of winds, the flow being anabatic during the day and katabatic at night, the latter being of considerable force.
RIVER SYSTEM
Chamoli district is criss-crossed by several important rivers and their tributaries. Alaknanda, traversing a distance of 229 kms. before it confluence with Bhagirathi at Devprayag and constituting the Ganga, is the major river.
The Alaknanda originates at a height of 3641 meters below Balakun peak 16 km. upstream from Badrinath form the two glaciers of Bhagirath Kharak and Satopanth. The two glaciers rise from the eastern slopes of Chaukhamba (7140 Meters) peak, Badrinath peak and its satellite peaks. These peaks separates the Gangotri group of glaciers in the west. The major portion of the Alaknanda basin falls in Chamoli district. From its source upto Hallang (58 Km),the valley is treated as upper Alaknanda valley. The remaining part of the area is known as lower Alanknanda valley. While moving from its source, the river flows in a narrow deep gorge between the mountain slopes of Alkapuri, from which it drives its name. All along its course, it drains its tributaries –
- Saraswati joins the Alaknanda 9 Km downstream from Mana.
- Khilrawan Ganga join it below the Badrinath shrine and Bhuynder Ganga below HanumanChatti.
- Dhauli Ganga meets at Vishnuprayag above Joshimath. The river Dhauliganga rises from the Nitti Pass at about 5070 meters. Its valley lies between the Kamet groups of peaks in the west and Nandadevi group in the east. The Dhauli takes a northern course at Malari. Between Malari and Tapovan, it is almost a narrow gorge with perpendicular cliffs on either side. several thousand meters high. the Dhauliganga in its turn is fed by GirthiGanga at Kurkuti and Rishiganga 500 mts. below Reni.
- Downstream small tributaries- Helang, Garud, Patal and Birahiganga join the Alaknanda between Joshimath and Chamoli.
- Nandakini, which rises from Semudra Glaciers drainage the western slopes of Trishul mountains, joins it at Nandprayag.
- South-East, river Pinddar joins the Alaknanda at Karnprayag. The Pinddar river is fed by the Milam and Pinddar glacier from the Nandadevi group of glacier. The Pinddar river, before joining Alaknanda, is fed by Kaliganga and Bheriganga.
- The rivers of Chamoli district, generally flow with great force in steep and narrow channels often resulting in excessive erosion and collapse of the banks.