Earth Structure and Geomorphology MCQs

This excludes the Ghana gold deposit evidence. The similarity of gold-bearing formations across the Atlantic was cited by Wegener as supporting evidence for continental drift.

This excludes the Gondwana sediment correlation. The Gondwana system of sediments found across India, Africa, South America, Antarctica, and Australia is a key evidence for continental drift.

This excludes the rock belt matching evidence. The geological continuity of Precambrian rock formations from Brazil to West Africa was one of the earliest and strongest arguments for continental drift.

Statement III is incorrect because clay is actually porous; its fine particles can hold water in tiny spaces. However, clay's extremely small pore size makes it effectively impermeable, not non-porous.

Statement III claims clay is not at all porous, which is factually wrong. Clay has porosity but very low permeability due to its fine grain size, so both statements cannot be correct.

Statement II is correct. Chalk is indeed porous and can absorb water through its connected pore spaces and joints, which explains its high permeability.

While both statements are factually correct, solar flares impact the magnetosphere and ionosphere but are not the mechanism behind the observed polar drift or rotational shift.

Both Statement II and Statement III are individually true. Solar flares do bombard the outer atmosphere, and polar meltwater does migrate equatorward.

Both statements are factually accurate. Solar flares deliver energy to the magnetosphere, and polar ice melt redistributes water mass toward lower latitudes.

Both statements correctly explain weathering. Carbonic acid from dissolved CO2 causes carbonation of feldspar and limestone, while dissolved oxygen causes oxidation of ferrous minerals. Both are valid explanatory mechanisms.

Both Statement II and Statement III are factually correct. Rainwater dissolves both CO2 and O2 from the atmosphere during precipitation.

Both statements are correct. Rainwater is a natural solvent that absorbs atmospheric gases including carbon dioxide and oxygen as it falls.

Volcanic eruptions produce far more than one of these. Pyroclasts, ash, and volcanic gases containing nitrogen and sulphur compounds are all well-documented volcanic products.

All four items are volcanic products. Besides solid ejecta like pyroclasts and ash, volcanoes release gases including SO2, H2S, and nitrogen oxides.

All four are correct, not just three. Volcanic gases contain both sulphur compounds (SO2, H2S) and nitrogen compounds alongside the solid pyroclastic debris and ash.

Statement 2 is also correct. S-waves (secondary waves) are transverse waves that move particles perpendicular to the direction of wave propagation, unlike P-waves which are longitudinal.

Statement 1 is also correct. P-waves (primary waves) travel faster than S-waves through rock and are always the first to be recorded on a seismograph.

Both statements are well-established facts in seismology. P-waves arrive before S-waves, and S-waves are transverse in nature.

Denisovans are not dinosaurs. They were a group of archaic humans who lived alongside Homo sapiens and Neanderthals during the Pleistocene epoch.

The name derives from Denisova Cave in the Altai Mountains of Siberia, Russia — not from a cave system in North-East India.

Denisovan refers to a hominin species, not a geological time period. The name comes from the Denisova Cave where their remains were first discovered.

On 21st June the Antarctic Circle experiences 24 hours of darkness, not continuous daylight. The midnight sun occurs there around 21st December.

On 21st June the Sun is overhead at the Tropic of Cancer (23.5°N), not at the Equator. The Sun is directly overhead at the Equator during the equinoxes (21st March and 23rd September).

The Sun shines vertically overhead at the Tropic of Capricorn on 22nd December (winter solstice), not on 21st June.

Heavy sand mining does not decrease salinity. In fact, excessive sand removal can increase salinity intrusion in coastal areas by lowering the riverbed.

Decreased salinity is not a consequence of sand mining. Sand mining can actually increase salinity, especially in estuarine areas, by deepening the channel and allowing saltwater intrusion.

Statement 1 is incorrect. Sand mining does not decrease salinity; it may increase it due to saltwater intrusion from deepened riverbeds near coasts.

Glacial cycles also influenced evolution. Repeated glaciations caused habitat fragmentation, sea-level changes, and climate shifts that drove speciation and extinction events.

Continental drift also influenced evolution. The separation and collision of continents isolated and reconnected populations, driving divergent evolution and biogeographic distribution patterns.

Both phenomena profoundly influenced the evolution of organisms through habitat isolation, climate change, and altered biogeographic connections.

Contour bunding is not used in desert margins with wind erosion. Wind breaks and shelter belts are the appropriate techniques for wind-prone areas.

Contour bunding is not suited for low flat plains near streams. Embankments and levees are more appropriate for flood-prone areas.

Contour bunding is not related to weed control in scrublands. It is a water and soil conservation technique.

Rotation causes the daily cycle of day and night but does not explain seasonal variation in their lengths. The tilt during revolution is the key factor.

The elliptical orbit affects the Earth-Sun distance slightly but does not significantly explain seasonal day-length variation. The axial tilt is the primary cause.

Latitude determines the magnitude of day-length variation but is not itself the cause. The cause is the revolution of the tilted Earth around the Sun.