Which of the following statements with regard to the Indian Peninsular Plateau is/are correct ? 1. The Southern plateau block is formed mainly of granite and gneiss 2. The Deccan lava plateau is an elevated tableland consisting of horizontally } arranged lava sheets 3. The Malwa plateau dominates the Vindhyan scraps, forming the Eastern flank of the plateau 4. The trough of the Narmada and Tapti is interposed between the Vindhyan and the Satpura ranges Select the correct answer using the code given below :

1. Geological Origin: The Gondwanaland Heritage (basic)

Concept: Geological Origin: The Gondwanaland Heritage

2. Archean Rock Systems: Granite and Gneiss Foundation (intermediate)

To understand the physical landscape of India, we must first look at its "Basement Complex"—the ancient, foundational layer of rocks known as the Archean Rock System. These are the oldest rocks in the crust, dating back to the Precambrian Era (specifically the Archean Eon, more than 2.5 billion years ago). Think of them as the "geological floor" of the Indian subcontinent; every other mountain range, river basin, or soil layer was eventually built on top of this massive, crystalline base Geography of India, Majid Husain, Chapter 1, p.4.

These rocks are primarily igneous (formed from the cooling of molten magma) and metamorphic (transformed by intense heat and pressure). Because they formed when the Earth's crust was first cooling, they are Azoic, meaning they contain absolutely no fossils—life hadn't evolved enough to leave a trace! The mineral composition is quite diverse, including minerals like quartz, orthoclase, muscovite, and biotite Geography of India, Majid Husain, Chapter 1, p.4. In India, these rocks are the core of the Peninsular Plateau, a stable landmass that was once part of the ancient Gondwanaland Contemporary India-I, Geography, Class IX, Chapter 2, p.12.

Geologists often refer to these as Archean Gneiss and Schists. In India, we see famous regional variations of these rocks:

• Bundelkhand Gneiss: Massive, coarse-grained granitoid rocks found in Uttar Pradesh and Madhya Pradesh Geography of India, Majid Husain, Chapter 1, p.5.
• Nilgiri Gneiss (Charnockites): Dark-colored, eruptive-looking gneisses found in the Southern hills Geography of India, Majid Husain, Chapter 1, p.6.
• Bengal Gneiss: Highly foliated rocks first identified in the Midnapur region.

Feature	Archean Granite	Archean Gneiss
Origin	Primary Igneous (magma cooling)	Metamorphic (re-crystallized Granite)
Texture	Crystalline and massive	Foliated or banded appearance
Fossils	None (Azoic)	None (Azoic)

Sources: Geography of India, Majid Husain, Chapter 1: Geological Structure and formation of India, p.4; Geography of India, Majid Husain, Chapter 1: Geological Structure and formation of India, p.5; Geography of India, Majid Husain, Chapter 1: Geological Structure and formation of India, p.6; Contemporary India-I, Geography, Class IX, Chapter 2: Physical Features of India, p.12

3. Broad Divisions: Central Highlands vs. Deccan Plateau (basic)

The Peninsular Plateau is the oldest and most stable landmass of India, having formed from the breaking and drifting of the ancient Gondwanaland. Unlike the Himalayas, which are young and rugged, this plateau is a vast tableland characterized by rounded hills and broad, shallow valleys CONTEMPORARY INDIA-I, Chapter 2, p.12. Geologically, it is a complex mosaic of ancient Archaean granites and gneisses, along with metamorphic rocks like marble and slate INDIA PHYSICAL ENVIRONMENT, Chapter 2, p.13. To understand its geography, we divide it into two primary regions separated roughly by the Narmada River: the Central Highlands and the Deccan Plateau.

The Central Highlands lie to the north of the Narmada River. This region encompasses the Malwa Plateau and is bounded by two iconic mountain ranges: the Aravalis to the northwest (which are highly denuded relict mountains) and the Vindhyan Range to the south CONTEMPORARY INDIA-I, Chapter 2, p.12. As you move eastward, the highlands extend into the Bundelkhand and Baghelkhand regions, eventually reaching the mineral-rich Chotanagpur Plateau Geography of India, Chapter 2, p.55. Interestingly, while most of the Peninsular rivers flow eastward, the Narmada and Tapti are exceptions; they flow westward through deep rift valleys or troughs created by tectonic faults between the Vindhyas and the Satpuras.

The Deccan Plateau is a massive triangular landmass situated south of the Narmada River. Its broad base in the north is formed by the Satpura Range, while its eastern and western edges are defined by the Eastern and Western Ghats respectively CONTEMPORARY INDIA-I, Chapter 2, p.12. A defining feature of this region is the Deccan Trap—a vast elevated tableland of basaltic lava sheets. These were formed by volcanic eruptions millions of years ago, resulting in the fertile black soil (regur) that characterizes much of western and central India Geography of India, Chapter 1, p.19-20.

Feature	Central Highlands	Deccan Plateau
Location	North of Narmada River	South of Narmada River
Key Components	Malwa, Bundelkhand, Chotanagpur	Deccan Trap, Karnataka & Telangana Plateaus
Boundaries	Aravalis (NW), Vindhyas (S)	Satpura (N), Western & Eastern Ghats
Primary Soil	Mixed Red and Black soils	Predominantly Black soil (Deccan Trap)

Sources: CONTEMPORARY INDIA-I, Physical Features of India, p.12; Geography of India (Majid Husain), Geological Structure and formation of India, p.19-20; Geography of India (Majid Husain), Physiography, p.55; INDIA PHYSICAL ENVIRONMENT, Structure and Physiography, p.13

4. The Deccan Trap: Basaltic Lava and Step Topography (intermediate)

The Deccan Trap is one of the most significant geological features of India, representing a massive volcanic province that formed towards the end of the Cretaceous Period (roughly 146 to 65 million years ago) Geography of India, Majid Husain, Chapter 1, p.19. Unlike the explosive volcanoes we often see in movies, this plateau was formed by fissure eruptions (or Hawaiian-type eruptions). In this process, the earth’s crust developed deep cracks or fissures, allowing highly fluid basaltic lava to pour out and spread across vast distances rather than piling up into a single mountain peak Geography of India, Majid Husain, Chapter 2, p.51. Over millions of years, these eruptions occurred in successive pulses. Each pulse laid down a new sheet of lava on top of the previous one. This resulted in a massive thickness of basalt—reaching up to 3,000 meters along the Mumbai coast and thinning out as you move inland toward places like Amarkantak or Belgaum Geography of India, Majid Husain, Chapter 1, p.20. Because these lava flows were horizontal and cooled into hard rock, subsequent weathering and erosion have carved them into a landscape that looks like a giant set of stairs. This is why it is called a "Trap," derived from the Swedish word 'Trappa', meaning stairs or steps. An interesting detail for your notes is that these lava flows aren't always continuous rock. They are often separated by "inter-trappean beds"—sedimentary layers formed during the quiet periods between volcanic pulses Geography of India, Majid Husain, Chapter 1, p.20. Today, this region is economically vital as the basalt is used for construction, and the weathering of these rocks has produced the fertile Black Soil (Regur), which is famous for cotton cultivation.

Sources: Geography of India ,Majid Husain, (McGrawHill 9th ed.), Chapter 1: Geological Structure and formation of India, p.19; Geography of India ,Majid Husain, (McGrawHill 9th ed.), Chapter 1: Geological Structure and formation of India, p.20; Geography of India ,Majid Husain, (McGrawHill 9th ed.), Chapter 2: Physiography, p.51

5. Tectonic Faults: Narmada and Tapti Rift Valleys (intermediate)

To understand the physical landscape of Central India, we must look at the **Narmada and Tapti Rift Valleys**, which are unique tectonic features in an otherwise stable Peninsular Plateau. A rift valley (or **graben**) is a linear lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. While most rivers in Peninsular India flow eastward toward the Bay of Bengal due to the plateau's general tilt, the Narmada and Tapti are famous exceptions. They flow westward because they are 'trapped' within deep tectonic troughs formed by the cracking and subsidence of the Earth's crust Geography of India by Majid Husain, Physiography, p.55.

The formation of these rifts is a story of immense pressure. As the Indian Plate drifted north and collided with the Eurasian Plate to form the Himalayas, the resulting stress caused the northern part of the ancient Peninsular shield to bend and buckle. This mechanical stress created parallel faults, causing the land between them to sink. The **Narmada River** occupies a major rift valley situated between the **Vindhyan Range** to its north and the **Satpura Range** to its south. The **Tapti River**, though shorter, follows a similar path further south, flowing in a more constricted rift between the **Satpura Range** and the **Ajanta Range** Geography of India by Majid Husain, The Drainage System of India, p.20.

This arrangement creates a unique "sandwich" of landforms as shown below:

Feature	Northern Boundary	Southern Boundary
Narmada Rift Valley	Vindhyan Range	Satpura Range
Satpura Range (Horst)	Narmada Valley	Tapti Valley
Tapti Rift Valley	Satpura Range	Ajanta / Satmala Range

Sources: Geography of India by Majid Husain, Physiography, p.55; Geography of India by Majid Husain, The Drainage System of India, p.20; Physical Geography by PMF IAS, Divergent Boundary, p.128

6. Micro-Physiography: Malwa, Bundelkhand, and Vindhyan Scraps (exam-level)

The Central Highlands form the northern core of the Peninsular Plateau, situated primarily to the north of the Narmada River. This region is a classic example of an old, stable landmass composed of crystalline, igneous, and metamorphic rocks, having survived the drifting of Gondwanaland CONTEMPORARY INDIA-I, Chapter 2, p.12. The landscape here is characterized by broad, shallow valleys and rounded hills, representing a highly denuded topography where ancient mountains have been worn down over aeons. At the heart of this region lies the Malwa Plateau, an elevated tableland that slopes gently toward the north. It is structurally defined by its neighbors: the Aravalis to the northwest and the Vindhyan Range to the south Geography of India, Chapter 2, p.54. To its east, it transitions into the Bundelkhand upland. The Malwa region is particularly famous for its 'rolling' surface and the deep ravines or badlands created by the Chambal river and its tributaries, which have carved through the soft soil and basaltic layers. Moving further east, we encounter the Bundelkhand and Baghelkhand plateaus. Bundelkhand is a rugged upland stretching across parts of Uttar Pradesh and Madhya Pradesh, bounded by the Yamuna River in the north and the Vindhyas in the south Geography of India, Chapter 2, p.54. A critical micro-physiographic detail to remember is the role of the Vindhyan Scarplands (or scraps). These prominent, steep-sided cliffs do not flank the Malwa plateau’s east; rather, they form the eastern and southeastern flanks of the Bundelkhand upland, creating a dramatic transition between the plateau and the surrounding plains. The Vindhyan System itself is a massive geological formation extending from Gujarat to Bihar. It acts as a primary water-divide between the Ganga river system and the Peninsular drainage Geography of India, Chapter 1, p.13. These mountains are not just physical barriers but economic powerhouses, rich in red sandstone, limestone for cement, and even diamondiferous deposits. Notably, the Great Boundary Fault (GBF) serves as a major geological suture, separating the older Aravalis from the younger Vindhyan rocks Geography of India, Chapter 1, p.13.

Sources: CONTEMPORARY INDIA-I ,Geography, Class IX, Chapter 2: Physical Features of India, p.12; Geography of India ,Majid Husain, (McGrawHill 9th ed.), Chapter 2: Physiography, p.54; Geography of India ,Majid Husain, (McGrawHill 9th ed.), Chapter 1: Geological Structure and formation of India, p.13

7. Solving the Original PYQ (exam-level)

This question beautifully integrates the three pillars of Indian physiography you have just studied: geological composition, volcanic morphology, and structural drainage. To solve this, you must synthesize the fact that the Peninsular Plateau is a relic of Gondwanaland, where the ancient Archaean basement (Statement 1) meets the relatively younger basaltic flows of the Cretaceous period (Statement 2). Statement 4 tests your grasp of the rift valley systems, specifically how the Narmada and Tapti rivers are "interposed" or tucked between the major block mountains of Central India, as detailed in NCERT Class IX: Contemporary India-I.

Let’s apply logical verification to arrive at the solution. You know that the southern block is part of the oldest landmass, meaning granite and gneiss are the foundational rocks; thus, Statement 1 is correct. Moving to the Deccan Trap, the term "lava sheets" in Statement 2 is a technical giveaway for the step-like topography formed by cooling basaltic eruptions. Statement 4 is a foundational geographical fact: the Narmada flows through a trough/rift between the Vindhyas and Satpuras. However, Statement 3 contains a classic UPSC spatial trap. While the Malwa Plateau is bounded by the Vindhyas, it is the Bundelkhand and Baghelkhand uplands that are characterized by the Vindhyan scarplands on their eastern flanks, rather than Malwa itself, according to Majid Husain: Geography of India.

The reasoning process should lead you to eliminate any option containing Statement 3. By identifying that the Malwa plateau’s relationship with the eastern scarps is described incorrectly, you can narrow your choices down. Since Statements 1, 2, and 4 are all robustly supported by geological and topographical evidence, the correct answer is (B). Always watch out for directional misplacements in UPSC questions—examiners often take a correct physical feature and associate it with the wrong geographic neighbor to test the precision of your mental map.