The hard crystalline massif formation the core of the region is, in fact, an extension of the Deccan Plateau. The latter extends underground from the Rajmahal hills of Chotanagpur Plateau below Malda districts of West Bengal and Rajshahi, Dinajpur and Rangpur districts of Bangladesh and appears in Northeast above the surface as Meghalaya Plateau and Karbi Plateau or Mikir Hills.
Geography of the Meghalaya Plateau
The Meghalaya-Karbi Plateau region extends from 250 05/
- 260 41/ N and 890 47/ – 930
36/ E. The Meghalaya plateau is traditionally divided into Garo,
Khasi and Jaintia Hills.
The region from the river Dhansiri in the east to the
Singimari River on the west is about 400 km long with an average width of about
40 km, covering about 35, 291 km2. It stands high above to the south
of the Assam valley at an altitude varying between 610 m and 1,830 m.
The Karbi Plateau or Mikir Hills has comprised the Karbi
and Rangma Hills. The Karbi Plateau is almost isolated from the Meghalaya
plateau by age-long erosion of the headstreams of the Kopili and Dhansiri River.
Although a part of the Deccan Plateau, the Meghalaya-Karbi
group of plateaus is topographically different from the former in that they
present more a hilly character with hills, ranges, deep valleys and gorges.
Physiography of the Meghalaya Plateau
The physiographic characteristic of the region is remarkable
due to the highly dissected and irregular terrain in the western and northern
face in contrast to the regular and steep fall of the southern face, down to
the Barak-Surma Plain through the faulted face.
The western part that is, the Garo Hills is an extensively
dissected tract of 7769.9 km2 with an average elevation of 900 m or
less. The Garo plateau rises to a distinct east-west range known as the Tura
Range or Kylas range just south of Tura. This range higher than 1100m and
reaches its highest point at Mount Norkrek (1529m).
To the east of the Garo Hills lie the higher Khasi Hills.
This is the highest part of the Meghalaya Plateau with an average height of 1066
m. However, its central upland conversing am area of 1250 km2 is
still higher and reaches a general height of 1400m.
There runs in this highland an east-west range known as the
Shillong Range with its highest Shillong peak reaching 1961 m. The highest point in Meghalaya is Shillong Peak, in the Khasi Hills overlooking the city of
Shillong
The easternmost part of the Meghalaya plateau is the Jaintia Hills. It consists of Jaintia Hills district of Meghalaya and Hamren Sub-Division of Karbi Anglong district of Assam and is bounded in the by Kapili River flowing to the plateau slopes down from Khasi hills from 1200 m to about 500 m in the east, the average height being 900 m and covering an area of 3790 km2.
The Karbi Plateau, which is the easternmost part of the north-eastward projection of Gondwanaland lies almost detached from the Meghalayan Plateau. Read More
Geology of Meghalaya Plateau
Geologically the Meghalaya plateau comprises of rocks from
the oldest Precambrian gneissic complex to the Recent alluvium formations. The
stratigraphic sequence is as follows.
- Cretaceous
–Tertiary sediments
- The
Sylhet trap
- Lower
Gondwana rocks
- Shillong
Group of rocks
- Precambrian
gneissic complex (Basement gneiss)
The Precambrian gneissic complex comprising para and
orthogneisses, migmatites and the Shillong Group of rocks comprising mainly
quartzites are exposed in the central, eastern and northern parts of the
Meghalaya plateau. They are intruded by basic and ultrabasic intrusives and late
tectonic granite plutons.
The lower Gondwana rocks of Permo-Carboniferous age are
recognized at the western part of Garo Hills and consists of pebble bed,
sandstone, and carbonaceous shale.
The Sylhet trap of middle Jurassic age comprising mainly of
basalt, rhyolites, acid tuffs, is exposed in a narrow East-West strip along the southern border of Khasi Hills.
The Cretaceous-Tertiary sediments occupying the southern part
of the Meghalaya plateau comprises of the Khasi Group (arenaceous facies), the
Jaintia Group (calcareous facies) and the youngest formation the Garo Group
which is represented as Simsang, Bagmara and Chengapara formations.
Besides these the Dupi Tilla group of mid-Pliocene age occurs in the western part of Garo Hills and towards south of Khasi Hills. Isolated patches of older Alluvium overlie the Tertiary rocks along the southern and western borders of the State. The recent Alluvium formation is mostly found in the river valleys of Garo & Khasi Hills Districts.[1]
The state of Meghalaya is directly influenced by the southwest monsoon and the northeast winter winds. The four seasons of Meghalaya are - Spring - March and April, Summer (Monsoon) - May to September, Autumn - October and November and Winter - December to February.
During March and April, the atmosphere gradually warms up with the advent of Spring. From the middle of April the temperature starts rising to the maximum in the month of June and then decreases gradually. This period may be termed as the summer (Monsoon) Season. The maximum temperature recorded is 34 Celsius at Tura and West Garo Hills District and 28 Celsius at Shillong.[2]
With average annual rainfall as high as 12,000 mm (470 in)
in some areas, Meghalaya is the wettest place on earth.
The climate of Meghalaya varies with the altitude. The climate of Khasi and Jaintia Hills is uniquely pleasant and bracing. It is neither too warm in summer nor too cold in winter, but over the plains of Garo Hills, the climate is warm and humid, except in winter. True to its name, the Meghalaya sky seldom remains free of clouds. The average annual rainfall is about 1,150 cm. [3]
Biodiversity of Meghalaya Plateau
The total forest area in the State is 8,510 Sq. Km with only
993 Sq.Kms under the control of the State Government and the rest under the
District councils and private managements. The principal timber species are
Sal, Teak, Titachap, Gomari, Bol, Pine Birch and Makri-Sal.
The principal forest products include timber, bamboo, reed,
broomstick, cane, ipecac, medicinal herbs and plants, cinnamon and thatch
grass. Azaleas and rhododendrons grow wild in the forests of Khasi Hills and
Jaintia hills and many kinds of beautiful orchids are found in the woods.
Meghalaya is also rich in wildlife. There are elephants, tigers, bears, wild boars, leopards, golden cats, leopard cats and jungle cats, deer of various kind, binturongs, slow loris monkeys of different types including capped-langurs, golden langurs and hoolock, flying squirrels and giant squirrels.
There are also many rare and interesting birds including the hornbills, partridges, pheasants, teals, snipes geese, ducks and quails. All these are protected by law. The State has two National Parks, Viz, Nokrek and Balpakram and two Wildlife Sanctuaries, Viz, Nongkhyllem and Siju.[4]