CSIR NET Earth Science Mock Test - 1 Free Online Test 2026

• Kames are small hills of bedded sands and gravels which are deposited by melt water near or at the edge of retreating ice sheets.
• Terminal moraines are the end moraines. These are formed due to deposition of glacial tills across the retreating ice sheets.
• Outwash plains are the plains of well sorted sediments formed in front of end moraines due to deposition of sediments eroded from terminal moraines.
• Kettle holes are the depression in the outwash plains.
• Eskers are situated in the middle of ground moraines. These are long, narrow, sinuous and steep sided ridges of sands and gravels.

The rubidium-strontium dating method is a radiometric dating technique. It is used by scientists to determine the age of rocks and minerals from the quantities they contain of specific isotopes of rubidium (87Rb) and strontium (87Sr, 86Sr).

The utility of the rubidium–strontium isotope system results from the fact that 87Rb decays to 87Sr with a half-life of 49.23 billion years. Rb is a highly incompatible element. During partial melting of the mantle, Rb prefers to join the magmatic melt rather than remain in mantle minerals.

As a result, it is enriched in crustal rocks. The radiogenic daughter, 87Sr, is produced in this decay process. It was produced in rounds of stellar nucleosynthesis predating the creation of the Solar System. This method is not used for dating ice cores.

Confined aquifers are permeable rock units. They are found usually deeper under the ground than unconfined aquifers.

The confined aquifers are overlain by relatively impermeable rock or clay, which limits the groundwater movement into or out of the confined aquifers. In a confined aquifer the groundwater is under pressure and will rise up inside a borehole that is drilled into the aquifer. The water rises up to the level called the potentiometric surface.

When groundwater is pumped from a confined aquifer, the intergranular pressure of the aquifer increases and the pore water pressure of the aquifer decreases.

In an artesian flow, the water flows out of the borehole under natural pressure. Confined aquifers may be replenished by rain water or stream water that is infiltrating the rock at some considerable distance away from the confined aquifers.

The foliated structure is similar to lamellar in broader sense but in this case the individual sheets are paper thin, even thinner and can be easily separated. Example: Muscovite mica.

Some common materials have been assigned hardness values according to Mohs scale and may prove useful in determination of hardness of an unknown mineral quickly. Hardness of human finger nail varies between 1.5 and 2.5.

Mineralogy is the branch of geology dealing the wide range of aspects related to minerals like, their individual properties, mode of occurrence and mode of formation

Hardness decreases on decomposition of a mineral due to atmospheric attack on the surface. Hence, it must be checked on unweathered and unaltered surfaces

Hardness is an anisotropic property; a mineral may show different values in different directions.

Minerals with atoms of greater atomic radii show less density values compared with those made of atoms of smaller atomic radii.

Pyrolite is a rock that would exist if the mantle and crust of the earth were mixed together. Pyrolite is considered as an average earth rock.

It is depleted of iron and comparatively enriched in silica, magnesium, and calcium. The pyrolite rock consists of about three parts peridotite and one-part basalt.

The name pyrolite was coined to explain the chemical and mineralogic composition of the earth’s upper mantle.

The relative abundances of the principal metallic element components are similar to those in chondritic meteorites and the solar photosphere. Hence, it is reasonable to assume that approximately these abundances are applicable to the entire mantle.

Obsidian is an igneous rock. Obsidian forms when the molten rock materials cool very rapidly.

Due to this the atoms are unable to arrange themselves into any crystalline structure.

Obsidian is an amorphous material also known as a mineraloid. It has a smooth uniform texture that breaks with a conchoidal fracture.

The other important properties of obsidian are given below:

Sand has highest permeability of 5 because of loose sedimentation in its particle. So, well sorted sand has the highest permeability.

Permeability of sandy loam is 2.5. Permeability of Loam is 1.3. Permeability of clay loam is 1.3. Permeability of slit clay is 0.25. Permeability of clay is 0.05.

This is a question from igneous petrology and economic geology. Majority knows that kimberlite is the major source rock of Diamond. Like kimberlite lamproite is mafic to ultra mafic (which is Fe and Mg rich rocks). Composed of

phlogopite, pyroxene, amphibole, olivine and leucite as essential minerals with accessory spinel, ilmenite, perovskite etc. it is another original source of diamond. Argyle mine of north Australia is one single largest deposit of diamondiferous lamproite.

The land breeze is less extensive both vertically and horizontally than the sea breeze because temperature differences between land and sea are rarely as great at night as in the day time.

Limestone deposition plays an important role in carbon sequestration and climate change on a geological timescale. Limestones are polygenetic in origin and they can be detrital, Chemical or biochemical in origin. Dolomites are formed after limestone. Calcarenite is a type of limestone that is composed mainly of detrital sand-size and carbonate grains. Calcarenite is the carbonate equivalent of sandstone.

A red coloured and clayey soil horizon is B horizon. It is also referred as subsoil. It is the 4th layer toward the core from the earth’s surface. The uppermost layer is dark in colour due to the richness of humus. With humus decreasing towards core, colour of the soil gets lighter.

B horizon is lighter in colour (red in colour) than the layers above it. This layer has clay and mineral deposits and less organic materials (humus) and more amount of minerals than the layers above it. This layer is generally harder and more compact.

The minerals forming the mantle have different melting points and so do the rocks that are formed from these minerals.

The standard atmosphere or atm is a unit of pressure defined as 101325 Pa or bar.

The melting points of common F rock-forming minerals at a pressure of  atm are given below:

The term El Nino refers is large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the eastern and east-central Equatorial Pacific.

It mainly effects are likely to develop over North America during the upcoming winter season.

Warmer water of El Nino does weakening of the trade winds and Walker circulation. It also reduces upwelling at Peruvian Margin.

When cold air mass and warm air mass blow against each other, the boundary line of convergence separating the two air masses is termed as front.

When the warm air mass, moves upward over the cold air mass the front formed in such a situation is termed warm front.

On the contrary, when the cold air mass advances faster and undercuts the warm air mass and forces the warm air upwards, the front so formed is termed cold front. The frontal surface of cold front is steeper than that of a warm front.

Cold fronts usually move from north-west to southeast. The air behind a cold front is colder and drier than the air ahead of it. After a cold front pass, the shift in the direction of the wind and drop in the temperature and relative humidity occur.

Cirrostratus clouds are example of high clouds. Due to the presence of low temperatures and small quantities of water vapour at high altitudes, the high clouds are thin and white and they are made up primarily of ice crystals.

Altostratus clouds are considered as middle clouds because they are found at an altitude of 2,000 to 6,000 meters.

Nimbostratus and stratus clouds are considered as low clouds.

Opening of Drake Passage range and Tasman Gateway is in the Cenozoic era. The interpretation of the relationship between ocean circulation and global cooling of that time is complicated. Deterioration of the early Cenozoic greenhouse climate occurred in a series of steps, the largest being widespread and permanent glaciation of Antarctica.

Changes in ocean circulation and decreasing carbon dioxide levels may have both contributed to the “greenhouse-icehouse” climate transition; and results as planetary cooling. Cenzoic cooling influenced the separation of South America from Antarctica and subsequent formation of Drake Passage. The development of circum- Antarctic Circulation and as a consequence thermal isolation of the Antarctica triggering global cooling are occurred.

Thermal inversion occurs when a layer of warm air settles over a layer of cooler air that lies near the ground.

The warm air holds down the cool air and prevents pollutants from rising and scattering. Various aspects of the temperature inversion of surface layer in the Bay of Bengal are occurrence time, characteristics, stability, inter-annual variability and generating mechanism.

It occurs during winter (November-February). Thermal inversion occurs in the Bay due to the presence of a strong halocline is the major causative factor.

For inversion occurring in the northeastern Bay (where the surface water gains heat from atmosphere), surface advection of the less saline cold water from the head of the Bay and Irrawaddy basin is found to be the major causative factor.

Plate Tectonics results various processes (like mountain building, faulting, seismic events) mainly affect the crust layer of the Earth.

Subduction is the sideways and downward movement of the edge of a plate of the earth’s crust into the mantle beneath another plate.

Mountain building is the result of convergence of two continent plates.

When two divergent plate move in opposite direction, sea floor spreading occurs.

A mantle plume is an upwelling of abnormally hot rock within the Earth’s mantle. This process is not related to Plate Tectonics.

Slopes with a thick cover of regolith are known as transport limited slopes.

It was identified by Carson and Kirkby in 1972.

On these slopes, weathering produces material much faster than it is removed.

These are expected to be covered with a thick regolith that buries underlying surface irregularities in the hard rock, promotes vegetative growth and produces a gentle slope on the surface.

Albedo means whiteness in latin. Albedo is the measure of the diffused reflection of solar radiation out of the total solar radiation received by an astronomical body.

Surface albedo will be increased, and the net amount of solar radiation held by the Earth will be reduce when a reduction in the solar insolation-induced air temperature and results as snow fields and ice sheets expand.

Air temperature will be reduced further, resulting in glacial expansion.

Mass wasting wherein a mass rock or weathered debris moves downhill along a curved shear surface is defined as Rotational landslide.

A slide-type landslide is a down-slope movement of material that occurs along a distinctive surface of weakness such as a fault, joint or bedding plane. If the slip surface is straight then it is termed translational.

Lahr is a violent type of mudflow or debris flow down from a volcano, typically along a river valley.

Block glide is the sliding movement of a large block of rock over a surface that has been lubricated.

Kames are small hills of bedded sands and gravels which are deposited by melt water near or at the edge of retreating ice sheets.

Terminal moraines are the end moraines. These are formed due to deposition of glacial tills across the retreating ice sheets.

Outwash plains are the plains of well sorted sediments formed in front of end moraines due to deposition of sediments eroded from terminal moraines.

Kettle holes are the depression in the outwash plains.

Eskers are situated in the middle of ground moraines. These are long, narrow, sinuous and steep sided ridges of sands and gravels.

The winds that blow from sub-tropical high-pressure areas towards equatorial low-pressure areas called trade or easterly winds. Because of the Coriolis effect, the northern trade winds move away from the subtropical high in north-east direction.

In southern hemisphere, the trade winds diverge out of the sub-tropical high towards the equatorial low from the southeast direction. As the trade winds tend to blow mainly from the east, they are also known as the tropical easterlies.

The winds are constant in strength and direction. Trade winds sometimes contain intense depressions.

This rock is formed by the sea waters advancing over a coastal region covered with fragments of chert and other similar rocks.

Abrasive is more a qualitative than quantitative property and may be broadly defined as the resistance, which a stone offers to rubbing action of one kind or another.