The mountains

Excerpts from Ian Lockwood's The Western Ghats


Introduction

The Western Ghats stretch 1,440 km from the Tapti River north of Mumbai to the tip of the Indian peninsula at Kanyakumari. Composed of a variety of dissimilar mountain ranges, they form a near continuous wall, separating the wet Malabar Coast from the drier regions of peninsular India.

Rainmaker

The Western Ghats prevent the monsoon clouds from reaching the interiors of the peninsula and the forests on the slopes of the Western Ghats, acting much like a giant sponge, absorb the torrential rains and release the water in the ensuing drier seasons. Eastward flowing rivers like the Cauveri and Krishna are fed by the Western Ghats.

The Western Ghats present an amazing variety of mountain and forest habitats. Starting at Kanyakumari, the mountains rise abruptly from the plains and sea. In the wetter zones from Kerala north to Goa, fabulous evergreen rainforests teem with bird songs and the buzz of insects. Protected areas like Silent Valley, Periyar, and the Kalakad Mundanthurai Tiger Reserve still retain a hint of what was once a dominant vegetation type in the Western Ghats.

Above these forests, protected by high cliffs, are plateaus whose biotic composition is influenced by the colder temperatures and high-velocity winds. The unique grasslands / shola ecosystem, dominate the higher plateaus that have escaped development. Mukurti, Eravikulam, and Kudremukh retain examples of this unique ecosystem. Deciduous forests still carpet many of the slopes on the eastern rain-shadow of the Ghats. Protected areas in this zone, such as Nagarhole and Mudumalai, harbour an astounding variety of wildlife wealth, from small creatures to elephants and tigers.

From Karnataka northwards, the Ghats meet the expansive Deccan Plateau. The hills are lower in elevation, compared to the rugged mountains of the south. Composed of ancient basaltic lava flows, they fall in steep, dramatic ghats (steps) to the sea along the Konkan coast north of Goa.


A short lesson on orogeny (excerpt from Mukurti: an unforeseen wilderness)

The rich swards of Mukurti with their island forests roll away in the pearly mists to drop suddenly without any warning over vertiginous cliffs to the plains and plateaux of Kerala. To the north and west lies Wayanad, then Nilambur to the south west, and then Silent Valley and Attapadi to the south. This is a stunning country where overtowering edges meet quiet modulations. On a clear day we can see almost all of Mukurti in a glance, a seemingly vast and uninhabited land. In a single sweep of your head you might gaze upon crest-lines, escarpments, deep drops, bumps and bosses, as well as cloven and sheer faces that run for miles upon miles. There are horizontal and vertical planes intersecting dramatically at the edge of the Park, showing us in plain relief that we stand on the edge of Horst or block mountains produced by the processes of faulting and subsidence or upliftment along fracture lines.

The Nilgiris stand at 2500 m. On the other side of the Palghat Gap the Annamalai-High Range-Palni massif equals this height. Steep and high as they are, they are nevertheless fairly level at the top. They are geologically identical to the Central Mountains of Sri Lanka and are part of the mountain range that runs down the western edge of the peninsula: the Sahyadris or the Western Ghats.

The Ghats are part and parcel of that great mass of solid rock that is the Deccan. This means that their cores are very old. Metamorphic schists and gneiss dating back to the Archaean, some 2500 million years old form the bones of the giant's body. Within the very ancient masses, or even overlying them are more recent formations, younger intrusions of granitic rocks or overflows of basalt (up in the Traps at Mahabaleshwar, Maharashtra). Young or old, the Deccan is a big slab of hard, impervious rock, of continental proportions, and not a mile of it formed from the gradual accumulative processes of sedimentation.

Long, long ago, perhaps some 100 million years ago at least, India was part of Gondwanaland, the super-continent that included South America, Africa, Australia, Antarctica and Madagascar. Imagine this huddle of continents, clustered together in the lap of the primeval ocean, bearing our ancestral floras and faunas. Now picture this cluster breaking up and drifting apart, each jagged plate carrying a few of the plants as it slipped away. Imagine the Indian plate, a huge and triangular chunk of land, moving, sliding slowly on a 40 million year long ocean journey, to eventually dock into the soft underbelly of the gigantic Asian landmass. Imagine the earth wave that followed, heaving up the Himalayas, tilting up the Ghats, rocking and bucking the ancient Deccan peninsula over the course of several million years.

Subsidence, upliftment, collision, faulting and folding happen when the jigsaw puzzle of continental crusts rearranges itself. Continents suffer from strains of various kinds as they move about the earth's surface. (And they move because the sea floors spread as molten magma seeps out of the Earth's interior along the ocean trenches). Plate tectonics brought India to fuse with Asia, it folded up the Tethys Sea into the Himalayas, elbowed in the Western Ghats and pushed down the Arabian Sea. It also punched up the high plateaux in the southern half of the Ghats, otherwise called the Nilgiris, the Annamalais, The High Ranges and the Palni Hills.

The Western Ghats gallery

For further information, and until we complete this section, please read Wikipedia on the Western Ghats. You can also subscribe to the Western Ghats google group for daily news and hot views on the region's environmental status and protection.