The Aravalli Range Explained

The Aravalli Range is a worn-down belt of ancient fold mountains running diagonally across north-western India, from the Delhi region through Haryana and Rajasthan into Gujarat, and it is widely regarded as one of the oldest mountain systems on Earth. Its name is often explained as “line of peaks”, and though most of those peaks are now low, rounded hills, the belt still shapes rivers, rainfall, groundwater, wildlife and the very edge of the Thar Desert. This explainer, last updated 4 November 2026, looks at the range as a piece of physical geography, geology and ecology rather than as a destination.

What makes the Aravalli special is not height but age and function. These rocks began forming in the Precambrian, billions of years before the Himalaya existed, and the range has been eroded for so long that only its stubby roots remain. Yet those roots hold metal ores, recharge aquifers, shelter leopards and form a green barrier that millions of people in Delhi, Gurugram and Jaipur quietly depend on.

Key Takeaways

• The Aravalli Range is a very old, deeply eroded fold-mountain belt stretching roughly 650 to 700 km from Gujarat through Rajasthan and Haryana to the edge of Delhi.
• Its highest point, Guru Shikhar near Mount Abu at about 1,720 m, is modest because hundreds of millions of years of erosion have worn the range down.
• The belt is rich in zinc, lead, copper, silver and building stones, and some of its mines were worked in ancient times.
• The range acts as a watershed, a groundwater recharge zone and a partial dust and heat buffer, though the idea that it single-handedly “holds back” the Thar Desert is a simplification.
• Mining, quarrying and construction have flattened or removed many hills, and legal debate over what counts as an Aravalli hill affects how much of it is protected.
• Restoring native vegetation and enforcing land-use rules along the range are widely seen as important for water security and air quality in north-west India.

What Exactly Is the Aravalli Range and Where Does It Lie?

The Aravalli Range is a discontinuous line of ridges, hills and plateaus that begins in the Delhi region, passes south-west through Haryana and across most of Rajasthan, and ends near Palanpur in northern Gujarat. Most of the belt, probably well over three-quarters of its length, lies in Rajasthan, where it forms a clear spine running from the north-east to the south-west and splits the state into two very different halves.

West and north-west of the line lies the dry sandy country of the Thar and its fringes, with little rainfall and sparse vegetation. East and south-east lies the more fertile Mewar and Hadoti country, drained by rivers such as the Chambal and its tributaries. The Aravalli therefore marks a sharp environmental contrast on the map: arid on one side, semi-arid to sub-humid on the other.

The range is not a single wall. In the north, near Delhi, it survives as scattered low ridges including the Delhi Ridge, and as scattered rocky outcrops across Haryana’s Gurugram, Faridabad, Nuh and Mahendragarh districts. In central Rajasthan the hills become broad and continuous near Ajmer, Udaipur and Rajsamand. In the south the range rises into its highest ground around Mount Abu, an isolated granite block that stands out from the plain.

How Old Are the Aravalli Mountains?

The rocks of the Aravalli belt are Precambrian in age, meaning they began forming more than half a billion years ago and, in the case of the oldest units, in the order of two billion years or more. Geologists describe an Aravalli-Delhi fold belt formed when ancient crustal blocks collided and squeezed thick piles of sediment and volcanic rock into folds, in episodes usually placed in the Proterozoic eon.

That is why the Aravalli is popularly called one of the oldest fold mountain ranges in the world. The claim is broadly sound but should be read with care. What is old are the rocks and the original mountain-building event; the present landscape is a battered remnant, and the surface has been repeatedly buried, exposed and re-sculpted since. Some other ranges elsewhere in the world also preserve extremely ancient roots, so “oldest” is better treated as a descriptive tradition than as a precisely ranked title.

The contrast with the Himalaya is striking. The Himalaya began rising only a few tens of millions of years ago, when the Indian plate ran into Asia, and it is still growing. The Aravalli, by comparison, finished its main growth very long ago and has been shrinking ever since. Geologists often suggest that the original Aravalli may once have stood as a lofty chain, perhaps comparable to young high ranges, before erosion stripped away thousands of metres of rock. This is a reconstruction rather than a measured fact, but it fits the exposed deep-seated rocks that now form the hills.

What Is the Aravalli Range Made Of?

The Aravalli Range is made mainly of metamorphosed sedimentary and volcanic rocks, such as quartzite, schist, phyllite and slate, intruded by granites and associated gneisses. These rocks were once layers of sand, mud and lava that were buried, baked and folded under great pressure, which toughened them and turned them into the hard, ridge-forming material seen today.

Geologists usually group them into two broad successions, the older Aravalli Supergroup and the younger Delhi Supergroup, separated by an ancient gap in the record. The Aravalli group includes phyllites, quartzites and some limestones and volcanic layers. The Delhi group contains thick quartzites that form the sharp northern ridges, together with marble and other carbonates. The famous white marble of the Makrana area and the marble quarries of central Rajasthan belong to this wider geological story.

Because the rocks are hard and fractured rather than soft and porous, rainwater seeps in through joints and cracks. This matters for groundwater: the fractured quartzite acts like a sponge-and-pipe system that recharges aquifers in the plains below, which is one reason hill loss near cities has such a direct effect on borewell levels.

Which Is the Highest Peak of the Aravalli Range?

The highest peak of the Aravalli Range is Guru Shikhar, rising to roughly 1,720 m above sea level on the Mount Abu plateau in Rajasthan’s Sirohi district. Mount Abu is geologically distinctive, a mass of granite and related rocks that was intruded and later exposed, so it sits as an island-like highland rather than as one link in a continuous ridge.

North of Abu the elevation drops quickly. Many of the central ranges near Udaipur, Ajmer and Alwar reach only a few hundred metres to a little over a thousand metres, and in Haryana and Delhi the hills are often just tens of metres above the surrounding plain. This is exactly why defining an “Aravalli hill” by height has become so contentious: a very large share of the surviving belt consists of low ridges that a strict elevation test could exclude, even though they perform the same ecological work.

How Does the Aravalli Shape the Thar Desert and Rajasthan’s Climate?

The Aravalli influences the Thar mainly as a physical and ecological boundary, but it does not simply “block” the desert, and its effect on the monsoon is subtler than many popular accounts suggest. The Arabian Sea branch of the south-west monsoon runs roughly parallel to the range, so the winds slide along its length instead of hitting it head-on, which means the hills cannot lift and wring out much of that moisture. This helps explain why the area west of the range stays so dry.

The range does, however, change local rainfall, temperature and wind. Its higher parts, especially around Mount Abu, receive noticeably more rain than the neighbouring plains. Its slopes and valleys hold denser scrub and forest that moderate local temperatures, and the belt acts as a partial obstacle to hot, dusty westerly winds that blow in from the desert. Gaps in the chain, however, let dust and sand drift eastward, and studies using satellite data have raised concern that thinning vegetation and quarried gaps could make it easier for desert conditions to creep towards the Delhi-Haryana plains.

The safest summary is that the Aravalli is a brake and a buffer rather than a wall. Its green cover tempers heat and dust, and its loss would likely worsen local aridity and air quality, but the main reason for the Thar’s dryness lies in larger atmospheric patterns, not just in this one range.

Which Rivers Rise in the Aravalli Range?

The Aravalli is the source of several important but mostly seasonal rivers, including the Banas, the Luni, the Sabarmati and the Sahibi, and it works as a major watershed of north-western India. Water falling on its eastern flank flows towards the Chambal and ultimately the Yamuna and Ganga system, while rivers on its western flank drain towards the Rann of Kutch, the Gulf of Khambhat or into sandy inland basins.

The Banas rises in the hills near Kumbhalgarh and flows east to join the Chambal. The Luni begins in the hills around Ajmer, flows south-west across the arid belt and mostly disappears into the salt flats of the Rann of Kutch, with water in it only for part of the year. The Sabarmati, which flows through Gujarat, also has its roots in the southern Aravalli. The Sahibi, which once flowed towards Delhi, is now largely a seasonal and heavily altered drain.

Because these rivers depend on a thin, patchy monsoon and on groundwater seepage from fractured rock, they are fragile. Many of the region’s lakes, from the Udaipur lake system to the Ajmer and Sambhar basins, are fed by Aravalli runoff, and a significant part of rural drinking water in the belt comes from traditional structures such as johads, baoris and tankas that capture hill water.

What Minerals and Natural Resources Does the Aravalli Hold?

The Aravalli belt is one of India’s richest mineral provinces, holding zinc, lead, copper, silver, rock phosphate, soapstone, mica, feldspar, limestone and a great range of building stones and marble. This wealth is a direct result of the same ancient geology: old volcanic and sedimentary systems concentrated metals, and later folding and heating moved them into workable deposits.

Zawar near Udaipur is often cited as a place where zinc was smelted in very early times, and mining at Zawar is recorded across many centuries. Copper from the Khetri belt in north-eastern Rajasthan has been worked for a very long time. Today the Rajpura-Dariba and Zawar areas remain important for zinc and lead, and Khetri for copper, while sandstone, marble, granite and slate are quarried across a broad belt.

The trade-off is obvious. The same hills that supply the raw material for cities are being quarried faster than they can be restored, and mine waste and dust have long-lasting environmental costs for the surrounding villages.

What Wildlife and Ecosystems Live in the Aravalli?

The Aravalli supports a mosaic of dry deciduous forest, thorn scrub, grassland and rocky habitat that shelters leopards, hyenas, jackals, sloth bears, wolves, nilgai, sambar and a large variety of birds and reptiles. The vegetation is dominated by drought-hardy species such as dhok, khejri, babool, salai and various thorny shrubs, which can survive long dry spells on thin, stony soil.

The range is also a hotspot for large carnivores outside the classic forest tiger belt. Leopards are well known in the hills of southern and central Rajasthan, where they live close to temples, villages and farmland, a pattern that has led to both fascination and conflict. Reserves and protected areas along or near the range include Mount Abu Wildlife Sanctuary, Kumbhalgarh, Sariska and the Ranthambore landscape at the meeting point of Aravalli and Vindhyan country, and the Delhi Ridge and Asola Bhatti sanctuary in the north.

Ecologically, the Aravalli also serves as a movement corridor. Animals and plants can travel along the chain between otherwise separate habitats, and when the chain is broken by roads, quarries and housing, wildlife populations become isolated. A reported example is the narrow strips that link Haryana’s hills to the Delhi Ridge, where tiny gaps decide whether leopards and other animals can move at all.

Why Is the Aravalli Under Threat?

The Aravalli is under threat mainly from mining, stone crushing, real-estate development and encroachment, which together have removed hills, fragmented forests and drained groundwater. Satellite studies and official inquiries have documented the disappearance of a number of hills in Rajasthan, and the Supreme Court has repeatedly intervened in mining cases in the Haryana and Rajasthan stretches of the range.

Several overlapping pressures can be identified:

• Quarrying and illegal mining that remove entire ridges and leave deep pits and dust.
• Construction and farmhouse development on hills close to Gurugram, Faridabad and other fast-growing towns.
• Declining groundwater in hard-rock aquifers that depend on healthy recharge zones.
• Invasive species such as Prosopis juliflora, which has spread across large areas and crowds out native trees.
• Overgrazing, firewood collection and forest fires in dry months.

A major legal and scientific argument concerns how the range is defined. If protection is applied only to landforms above a certain height or slope, many low but ecologically vital ridges may fall outside it, a concern raised by environmental groups and scientists. Official and judicial positions on the definition have been changing and contested, so readers should treat the exact legal boundary as a live question rather than a settled one.

What Is Being Done to Protect and Restore the Aravalli?

Protection efforts combine court orders, forest and wildlife laws, and large greening programmes, with the idea of restoring a continuous green belt along the range. Mining has been restricted in sensitive parts, notably in Haryana’s southern districts after Supreme Court orders, and eco-sensitive zones have been drawn around some protected areas.

The government has announced an Aravalli greening initiative, often described as a green wall, to plant native species along the length of the range across the four states, with a buffer around it. Alongside it, state forest departments and local groups run biodiversity parks, such as the one developed on former mining land near Gurugram, to show that degraded hills can recover with native plants and careful water management.

Scientists and conservationists generally stress that planting alone is not enough. Success depends on stopping new mining and construction in recharge zones, controlling invasive trees, protecting wildlife corridors and involving villages that depend on the hills for water and grazing. Monitoring by satellite and ground checks is also needed so that gains are not quietly reversed.

Why Does the Aravalli Matter for India’s Future?

The Aravalli matters because it protects water, air, biodiversity and livelihoods across one of the most densely populated and water-stressed parts of India. It recharges groundwater for cities like Delhi and Jaipur, supplies minerals and stone for the economy, and may help limit the spread of desert dust and heat into the north Indian plains.

It also carries cultural and historical weight. Forts such as Kumbhalgarh and Chittorgarh, great lakes and old step-wells are all products of a landscape in which the hills collected and held water. Understanding the range as a natural infrastructure, and not just a convenient source of stone, is the key shift that many hydrologists and ecologists are urging.

Bottom Line

The Aravalli Range is an ancient, low but vital mountain belt whose rocks record some of the deepest history of the Indian subcontinent. Its value today lies in the water it stores, the minerals it holds, the wildlife it shelters and the dust and heat it helps buffer. Treating it as a single living system, from the Delhi Ridge to Mount Abu, is the best chance of keeping it intact.

Frequently Asked Questions

Is the Aravalli really the oldest mountain range in the world?

The Aravalli is widely called one of the oldest fold mountain systems, because its rocks and original mountain-building date back to the Precambrian, over a billion years ago. The exact title of “oldest” is a tradition rather than a precise ranking, as other ancient ranges also exist.

What is the highest peak of the Aravalli Range?

The highest peak is Guru Shikhar at Mount Abu in Rajasthan, at roughly 1,720 m. It is an isolated granite highland rather than a smooth part of the main ridge.

Does the Aravalli stop the Thar Desert from spreading?

It helps as a partial barrier and green buffer against desert dust and hot winds, but it does not completely stop the desert. Gaps created by mining and clearing can allow sand and dust to move east, and the Thar’s dryness is mainly due to wider atmospheric patterns.

Which states does the Aravalli Range pass through?

The Aravalli runs through Gujarat, Rajasthan, Haryana and Delhi. Most of it, by far, lies in Rajasthan.

Why is mining in the Aravalli such a big issue?

Mining and quarrying remove hills, destroy habitat, create dust and lower groundwater recharge, and many of the affected areas serve fast-growing cities. Courts have restricted mining in parts of the range, but illegal extraction has repeatedly been reported.

What rivers originate in the Aravalli Range?

Rivers such as the Banas, Luni and Sabarmati rise in the Aravalli, along with the seasonal Sahibi. Most are rain-fed and flow only for part of the year.

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