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Q101. If a coarse-grained igneous rock is composed of >90% of plagioclase and <10% of olivine and pyroxene, then the name of this rock according to the IUGS classification is
The correct answer is anorthosite. According to the strict IUGS classification for igneous rocks, any coarse-grained rock that is overwhelmingly dominated by plagioclase feldspar (greater than 90%) is uniquely classified as an 'anorthosite'. If the rock had more dark minerals (olivine/pyroxene) it would drift into the gabbro family, but the extreme purity of plagioclase makes anorthosite the only correct classification.
Q102. In the context of phylogeny of horses, the CORRECT chronological order from old to young is
The correct answer is Hyracotherium, Mesohippus, Merychippus, Equus. The fossil record beautifully shows the evolution of horses over 50 million years. It started with 'Hyracotherium', a tiny, dog-sized forest animal with toes. It evolved into the slightly larger 'Mesohippus', then into the grazing plains-runner 'Merychippus'. Finally, it evolved into 'Equus', the large, single-hoofed modern horse we ride today. Any other sequence scrambles this well-documented evolutionary timeline.
Q103. Match the economic deposits (Group I) with their places of occurrence (Group II). P. Iron ore 1. Bhatan Q. Base metal 2. Sukinda R. Chromite 3. Rampura-Agucha S. Uranium 4. Bellary
The correct answer is P-4; Q-3; R-2; S-1. In Indian economic geology, Bellary (Karnataka) is globally famous for massive Iron ore deposits. Rampura-Agucha (Rajasthan) is the largest base metal (Zinc-Lead) mine in India. Sukinda (Odisha) holds nearly all of India's Chromite reserves. Finally, Bhatan (Jharkhand/Singhbhum shear zone) is a recognized site for Uranium mineralization.
Q104. Match the environment representing physical geological processes in Group I with the corresponding geomorphic landform/feature in Group II. P. Aeolian 1. Drumlin Q. Glacial 2. Tombolo R. Fluvial 3. Yardang S. Coastal 4. Natural levee
The correct answer is P-3; Q-1; R-4; S-2. Aeolian (wind) environments carve out aerodynamic rock ridges known as Yardangs. Glacial (ice) environments act like bulldozers, scraping and dumping dirt into streamlined hills called Drumlins. Fluvial (river) environments regularly flood and deposit high mud banks along their edges known as Natural levees. Coastal (ocean wave) environments build sand bars that connect islands to the mainland, known as Tombolos.
Q105. Match the items in Group I with the corresponding items in Group II. P. Chalcocite 1. Supergene enrichment Q. Bauxite 2. Mechanical accumulation R. Monazite placers 3. Magmatic crystallization S. Chromite 4. Residual processes
The correct answer is P-1; Q-4; R-2; S-3. Chalcocite is the classic copper ore formed when weathering washes metals downwards to perfectly concentrate just below the water table (Supergene enrichment). Bauxite is aluminum ore left behind when intense tropical weathering rots everything else away (Residual processes). Heavy Monazite sands are physically sorted by ocean waves and rivers (Mechanical accumulation). Chromite settles to the bottom of cooling magma chambers (Magmatic crystallization).
Q106. Match the minerals in Group I with the corresponding composition in Group II. P. Leucite 1. (K,Na)AlSi3O8 Q. Andradite 2. NaAlSi2O6 R. Sanidine 3. KAlSi2O6 S. Jadeite 4. Ca3Fe2Si3O12
The correct answer is P-3; Q-4; R-1; S-2. In mineral chemistry: Leucite is a potassium feldspathoid with the exact formula KAlSi2O6. Andradite is the calcium-iron variety of Garnet, defined perfectly as Ca3Fe2Si3O12. Sanidine is a high-temperature potassium/sodium feldspar, represented as (K,Na)AlSi3O8. Jadeite is a dense, high-pressure sodium pyroxene, strictly formulated as NaAlSi2O6.
Q107. Select the answer that is a CORRECT match for the three types of unconformities. P. Disconformity Q. Non-conformity R. Angular Unconformity
The correct answer is P-2; Q-3; R-1. Based on the standard visual representation of unconformities: An Angular Unconformity (1) shows flat sedimentary rocks resting on top of violently tilted older rocks. A Disconformity (2) shows flat sedimentary rocks resting on an eroded, wavy surface of older flat sedimentary rocks. A Non-conformity (3) shows sedimentary rocks resting directly on top of massive, crystalline igneous or metamorphic rock.
Q108. Select the youngest volcanic event out of the following.
The correct answer is Deccan volcanics. The Deccan volcanics (Deccan Traps) represent one of the largest volcanic eruptions in Earth's history, occurring at the very end of the Cretaceous period (about 66 million years ago). The Panjal and Dalma volcanics are extremely ancient (Paleozoic and Precambrian), and the Rajmahal volcanics erupted earlier in the Cretaceous (around 118 million years ago). Therefore, the Deccan event is the youngest.
Q109. The closest value to the percentage of the Earth’s surface covered by the oceans is
The correct answer is 70%. The Earth is famously known as the 'Blue Marble' because liquid water dominates its surface. Oceans and seas stretch across approximately 71% of the entire surface area of our planet, leaving only about 29% for all the dry land continents and islands. Therefore, 70% is the closest standard geological value among the given options.
Q110. The Earth’s radius is maximum at which one of the following latitudes?
The correct answer is 0°. The Earth is not a perfect, mathematical sphere. Because it spins so fast, the middle bulges outward like a squashed ball. This bulge is widest exactly at the equator, which is the 0° latitude line. Therefore, the distance from the core to the surface (the radius) is physically longest at the equator and shortest at the top and bottom poles (90°).