GATE GG-1 topic:geochemistry PYQs & Answers — Page 2

Questions 11–20 of 37. Imported answers require independent review unless marked reviewed.

Topic practice 37 questionsPage 2 of 4

In a hypothetical scenario, the element Y has 4 stable isotopes

Y and

Y. The isotope

Y is radiogenic and is formed by β

decay of the isotope

X of the element X with a half-life of 3.51 billion years. An igneous rock, which has behaved as a closed system, has three different minerals P, Q, and R, which crystallized from the same magma 2 billion years ago, with initial X/Y ratios of 1.75, 2.05, and 0.75, respectively. Which one of the following statements is true for the ratio

Y in this igneous rock in the present day?

Your answerChoose one option.

P > Q > R

R > P > Q

Q > P > R

Q > R > P

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Choose the explanation(s) for negative Eu anomalies in upper crustal rocks like granite and granodiorite.

Your answerSelect all correct options. You can choose more than one.

These rocks are end-products of magmatic differentiation

These rocks were formed by melting of the mantle, which was already depleted in Eu

Most of the Eu was incorporated in other minerals

The melt residues contain plagioclase which are enriched in Eu

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Which characteristic feature(s) best explain(s) the HIMU mantle reservoir?

Your answerSelect all correct options. You can choose more than one.

Magmas derived from this reservoir have high

and

Magmas derived from this reservoir have high

and

This reservoir has evolved with high Th/U

This reservoir has evolved with high U/Pb

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The composition of which one of the following reservoirs closely matches with that of iron meteorites?

Your answerChoose one option.

Primitive Mantle

Earth’s Core

Depleted Mantle

Bulk Silicate Earth

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Consider the solubility product of barite (BaSO₄) at 25 °C and 1 bar to be 10⁻¹⁰. If the activities of Ba²⁺ and SO₄²⁻ ions are 0.5 × 10⁻⁵ and 10⁻ˣ, respectively, then the absolute value of ‘X’ is ________ (rounded off to one decimal place).

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If the Rb-Sr isochron formed by a suite of gabbro samples has a slope of 0.0265, then the calculated age of the gabbro in million years is ________ (in integer).

[Use λ(⁸⁷Rb) = 1.42 × 10⁻¹¹ year⁻¹]

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The heat production (

) of a granitic rock due to decay of the radioactive elements U, Th and K having concentration

, and

, respectively, is given by the expression

Which one of the following correctly represents the relation between the magnitude of coefficients

(in

Your answerChoose one option.

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The behavior of trace elements in magmatic systems follows

Your answerChoose one option.

Henry’s Law

Raoult’s Law

Fick’s Second Law

First Law of Thermodynamics

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90% of the bulk Earth is constituted of Fe, Si, O and

Your answerChoose one option.

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Match the items in Group-I with corresponding appropriate items in Group-II.

Group-I P. Cs Q. Au R. Cd S. Rn

Group-II

Siderophile

Chalcophile

Atmophile

Lithophile

Your answerChoose one option.

P-4, Q-1, R-2, S-3

P-4, Q-3, R-1, S-2

P-3, Q-1, R-2, S-4

P-2, Q-1, R-4, S-3

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GATE GG-1 topic:geochemistry PYQs

Question 47

Question 53

Question 54

Question 29

Question 42

Question 64

Question 17

Question 28

Question 39

Question 38