With reference to the Himalayan range, which of the statements is/are correct ? 1. The sedimentary rocks of the greater Himalayas were fossil less. 2. Marine livings fossils are found in the sedimentary rocks of lesser Himalayas. 3. Remains of human civilization are found in outer or Shivalik Himalayas. Select the correct answer using the codes given below : Codes :
- (a)1 and 2 only
- (b)2 and 3 only
- (c)1 and 3 only
- (d)1, 2 and 3 are correct
Correct — D, all three statements are accepted. The question is testing the standard three-fold division of the Himalaya used in Indian geography textbooks, where each belt is identified by the kind of rock it is made of and by what those rocks preserve. (1) The Greater Himalaya or Himadri is built around a core of crystalline rock — granite, gneiss and schist — and such sedimentary material as is folded into that axial belt has been so thoroughly heated and squeezed that organic remains were destroyed; textbooks therefore describe the Himadri's rocks as unfossiliferous. Read the honest caveat in the 'traps' below before you carry this as a geological absolute. (2) The Lesser Himalaya or Himachal, between the Main Central Thrust and the Main Boundary Thrust, is largely a belt of compressed and altered but still recognisable sedimentary rock. Its Krol–Tal succession, exposed in the Mussoorie and Nainital hills, has yielded fossils of marine organisms, which is direct evidence that these sediments were laid down under the sea before the mountains rose. (3) The Outer Himalaya or Shiwalik is the youngest belt, made of soft, poorly consolidated sand, silt, clay and conglomerate washed off the rising mountains and dumped along their foot. These beds are one of the world's richest sources of Mio-Pleistocene vertebrate fossils, including the fossil ape Sivapithecus, and the Shiwalik–Soan foothill belt has also yielded Palaeolithic stone tools — the basis on which the paper calls them 'remains of human civilization'. Since the paper treats each of the three as true, the code covering all three is the answer.
- (a)1 and 2 only — It drops statement 3, but the Shiwaliks are precisely the Himalayan belt famous for fossil and early stone-age finds — their young, unconsolidated river-laid beds are the ideal burial medium, which is why the Shiwalik–Soan foothills are a classic hunting ground for vertebrate fossils and Palaeolithic tools.
- (b)2 and 3 only — It drops statement 1, which is the exam's stated position on the Greater Himalaya: its axial belt is crystalline and metamorphic, and the textbook description of those rocks is that they carry no fossils.
- (c)1 and 3 only — It drops statement 2, yet the marine fossils of the Lesser Himalaya are the standard textbook proof that the Himalayan sediments accumulated in the Tethys Sea before being uplifted.
The Himalaya is conventionally described as three roughly parallel, longitudinal belts separated by great thrust faults, each with its own rock character. The Greater Himalaya (Himadri) is the loftiest and is cored by ancient crystalline and metamorphic rock. South of it the Lesser Himalaya (Himachal) is a belt of intensely folded but still identifiable sedimentary and low-grade metamorphic rock. South of that again, and separated from it by the Main Boundary Thrust, lies the Outer Himalaya or Shiwalik — the youngest belt, made of the debris of the rising mountains themselves, laid down by rivers only a few million years ago. The fossil content of each belt follows from this: heavily metamorphosed rock loses its fossils, moderately altered marine sediment keeps them, and young river-laid sediment preserves the bones and tools of the animals and people that lived beside those rivers.
Do not try to memorise the three statements separately; derive them from the age-and-alteration gradient that runs north to south. Oldest and most cooked in the north (no fossils survive), marine sediments in the middle (sea fossils survive), youngest and softest in the south (land vertebrates and stone tools survive). That single gradient answers this question and most other 'match the Himalayan belt' items. The tempting error is to assume the tallest, grandest range must have the richest record — the opposite is true, because height here comes from deep burial, heat and pressure, all of which destroy fossils.
- Three-fold division from north to south: Greater Himalaya (Himadri), Lesser Himalaya (Himachal), Outer Himalaya (Shiwalik), separated by the Main Central Thrust and the Main Boundary Thrust.
- The Himadri is cored by granite, gneiss and schist; heat and pressure destroy fossils, which is why textbooks call its rocks unfossiliferous.
- The Lesser Himalaya's Krol–Tal sedimentary succession around Mussoorie and Nainital has yielded fossils of marine organisms, marking these rocks as former Tethys Sea deposits.
- The Shiwalik beds are young, largely unconsolidated river sediments and are among the world's richest sources of Mio-Pleistocene vertebrate fossils, including the fossil ape Sivapithecus.
- Palaeolithic stone-tool assemblages have been recovered from the Shiwalik–Soan foothill belt, which is what the paper means by 'remains of human civilization'.
- North of the Himadri crest lies the Tethys or Tibetan Himalaya, a marine sedimentary belt that is richly fossiliferous — see the caveat in 'traps'.
The fossil record improves as you move south and the rocks get younger and less altered — which is why the tallest belt is the emptiest one. The official key accepts all three statements, so all three rows are the answer.
- Statement 1 is the exam's position, not a settled geological absolute. The sedimentary sequence of the Tethys (Tibetan) Himalaya, which lies immediately north of the Himadri crest and is sometimes loosely counted with the 'Greater Himalaya', is in fact richly fossiliferous — the ammonites of the Spiti Shales are a standard example. The statement holds only under the narrow definition used in Indian geography textbooks, where the Greater Himalaya means the crystalline axial belt alone and the Tethys Himalaya is treated as a separate zone. Argue the key in the exam; know the nuance for interviews and for Mains.
- Assuming greater height means older, better-preserved rock. Height here comes from deep burial, heat and pressure — the very processes that erase fossils.
- Confusing the Shiwalik's hominoid and vertebrate fossils with Harappan-type 'civilisation'. What the foothills actually yield are Mio-Pleistocene animal fossils and Palaeolithic stone tools, i.e. very early human occupation, not urban remains.
UPPSC likes three-statement items that test whether you can attach a property — rock type, fossils, height, drainage — to the right Himalayan belt; UPSC prefers to reach the same syllabus through tectonics, drainage and the Bhabar–Terai–Dun landforms.
Consider the following statements made about the sedimentary rocks: I. Sedimentary rocks are formed at Earth’s surface by the hydrological system. II. The formation of sedimentary rocks involves the weathering of pre-existing rocks. III. Sedimentary rocks contain fossils. IV. Sedimentary rocks typically occur in layers. Which of these statements are correct?
- (a) I and II
- (b) I and IV
- (c) II, III and IV
- (d) I, II, III and IV
Answer(d) I, II, III and IV
The same underlying idea — that fossils are preserved in layered sedimentary rock and not in rock that has been melted or metamorphosed — which is exactly why the Himalayan belts differ in fossil content.
Which one of the following is the youngest mountain range of India ?
- (a) Himadri Range
- (b) Aravalli Range
- (c) Western Ghat
- (d) Vindhya Range
Answer(a) Himadri Range
Tests the same Himalayan structure from the age angle — the Himadri belt of this question is the one UPPSC asked about a year later as India's youngest fold-mountain range.
- practice — not a real PYQ
The Shiwalik range of the Himalaya is composed mainly of
- (a)granite and gneiss of Precambrian age
- (b)unconsolidated sand, silt, clay and conglomerate deposited by rivers
- (c)basaltic lava flows
- (d)marine limestone rich in coral
Answer(b) Unconsolidated sand, silt, clay and conglomerate deposited by rivers — the Shiwaliks are built of the debris eroded off the rising Himalaya, which is why they are the youngest, softest and most landslide-prone of the three belts.
- practice — not a real PYQ
Marine fossils found in Himalayan sedimentary rocks are taken as evidence that
- (a)the Himalaya was once covered by a large ice sheet
- (b)the rocks were formed by volcanic eruption under the sea
- (c)the sediments accumulated in the Tethys Sea before being uplifted into mountains
- (d)the Himalaya was formed by the erosion of the Deccan plateau
Answer(c) The sediments accumulated in the Tethys Sea before being uplifted — marine fossils in rock now standing kilometres above sea level are the classic evidence for the closing of the Tethys and the collision that raised the Himalaya.