<h4>Geographical Extent and Dimensions</h4><p>The <strong>Aravalli Range</strong> stretches across four Indian states, forming a significant geographical feature. It originates in <strong>Gujarat</strong> and extends through <strong>Rajasthan</strong> and <strong>Haryana</strong>, finally culminating in <strong>Delhi</strong>.</p><div class='info-box'><p><strong>Length:</strong> Approximately <strong>692 km</strong></p><p><strong>Width:</strong> Varies significantly, ranging from <strong>10 km to 120 km</strong></p></div><p>A substantial portion of the range lies within <strong>Rajasthan</strong>, accounting for about <strong>80%</strong> of its total length. The remaining <strong>20%</strong> is distributed across <strong>Haryana</strong>, <strong>Delhi</strong>, and <strong>Gujarat</strong>.</p><h4>Divisions within Rajasthan</h4><p>Within <strong>Rajasthan</strong>, where the range's extension is about <strong>560 km</strong>, the <strong>Aravalli Mountains</strong> are broadly categorized into two primary ranges. These divisions help in understanding the regional variations of the mountain system.</p><ul><li><strong>Sambhar Sirohi Range:</strong> One of the key segments of the Aravallis in Rajasthan.</li><li><strong>Sambhar Khetri Range:</strong> The other significant division, contributing to the range's extensive presence in the state.</li></ul><h4>Ecological Role: The Green Wall and Ecotone</h4><p>The <strong>Aravalli Range</strong> functions as a vital <strong>natural green wall</strong>. This barrier is crucial for ecological balance, particularly in western India.</p><p>It acts as an <strong>ecotone</strong>, which is a transitional area between two distinct ecosystems. In this context, the Aravallis form a critical zone between the arid <strong>Thar Desert</strong> and the fertile <strong>Gangetic Plain</strong>.</p><div class='key-point-box'><p><strong>Ecotone Definition:</strong> An <strong>ecotone</strong> is a region of transition between two or more diverse ecological communities, ecosystems, or biotic regions. It often exhibits characteristics of both adjacent communities and can be rich in biodiversity.</p></div><h4>Highest Peak: Gurushikhar</h4><p>The highest point of the <strong>Aravalli Range</strong> is <strong>Gurushikhar</strong>, located in <strong>Rajasthan</strong>. This peak is a prominent landmark and a significant geographical feature of the range.</p><div class='info-box'><p><strong>Peak Name:</strong> <strong>Gurushikhar</strong></p><p><strong>Location:</strong> <strong>Rajasthan</strong></p><p><strong>Elevation:</strong> <strong>1,722 meters</strong> above sea level</p></div><h4>Significance of Aravallis</h4><p>The range holds immense ecological and environmental significance, impacting regional climate, biodiversity, and water resources.</p><ul><li><strong>Desert Encroachment Prevention:</strong> The <strong>Aravallis</strong> are instrumental in preventing the eastward expansion of the <strong>Thar Desert</strong> into the more fertile <strong>Indo-Gangetic plains</strong>. This protective barrier is crucial for agricultural productivity and ecological stability.</li><li><strong>Catchment Area:</strong> Historically, the range has served as an important <strong>catchment area</strong> for numerous rivers and plains, contributing to regional water security.</li><li><strong>Biodiversity Hotspot:</strong> The Aravallis support a rich variety of flora and fauna, making it a significant biodiversity zone.</li><ul><li><strong>Plant Species:</strong> Home to approximately <strong>300 native plant species</strong>.</li><li><strong>Bird Species:</strong> Supports around <strong>120 bird species</strong>.</li><li><strong>Exclusive Animals:</strong> Provides habitat for unique animals such as <strong>jackals</strong> and <strong>mongooses</strong>.</li></ul></ul><div class='exam-tip-box'><p>The <strong>ecological significance</strong> of the Aravallis, especially its role as a barrier against desertification and a biodiversity hotspot, is a frequently tested concept in <strong>UPSC Prelims</strong> and <strong>Mains (GS Paper I &amp; III)</strong>. Remember to highlight its multi-faceted importance.</p></div>