List of top Geology Questions on Geochemistry asked in GATE GG

In a hypothetical rock, the Kd values of element E in minerals M1, M2, and M3 are 1.5, 1.0, and 0.5, respectively. The modal abundances of M1, M2, and M3 are 10%, 40%, and 50%, respectively. The bulk partition coefficient of element E in this rock is ________
Which characteristic feature(s) best explain(s) the HIMU mantle reservoir?
Choose the explanation(s) for negative Eu anomalies in upper crustal rocks like granite and granodiorite.
In a hypothetical scenario, the element Y has 4 stable isotopes \(^{197}{Y}\), \(^{198}{Y}\), \(^{199}{Y}\), and \(^{200}{Y}\). The isotope \(^{199}{Y}\) is radiogenic and is formed by \(\beta^-\)-decay of the isotope \(^{199}{X}\) 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 \(^{199}{Y}/^{200}{Y}\) in this igneous rock in the present day?
A particular Index of Alteration (IA) is defined as the molar concentration ratio (expressed as weight percentage) of fluid immobile element(s) to fluid mobile element(s) and is expressed by \(100 \times \left(\frac{[Al_2O_3]}{[Al_2O_3] + [Na_2O] + [K_2O]}\right)\). For chemical weathering of silicate rocks, which one of the following statements is correct?
In a hypothetical rock, the Kd values of element E in minerals M1, M2, and M3 are 1.5, 1.0, and 0.5, respectively. The modal abundances of M1, M2, and M3 are 10%, 40%, and 50%, respectively. The bulk partition coefficient of element E in this rock is ________
Compared to Fe, Mg, and Ca, the content of K is extremely low in igneous clinopyroxene. Which of the following CANNOT explain its low abundance?

Which one of the following statements correctly describes the features in the geological map? 


 

Shown below is a schematic plot of \(\varepsilon_{Nd}\) (deviation of \(^{143}Nd/^{144}Nd\) in a sample relative to CHUR) versus time. The two solid lines represent the evolution curves for the depleted mantle reservoir and the continental crust. Which one of the four dashed lines, marked 1, 2, 3, and 4, represents the evolution of the CHUR? 


 

During a geochemical exploration survey in a hilly terrain, Cu concentration of stream sediments from a third order basin outlet was measured to be 3000 ppm. Considering a catchment area of 10 km\(^2\) and a Cu background value of 200 ppm, which one of the following options is the productivity of this catchment for Cu?
Which one of the following statements explains why elements Li, Be, and B have low cosmic abundance?
90% of the bulk Earth is constituted of Fe, Si, O and:
The behavior of trace elements in magmatic systems follows:
Match the Volcanogenic Massive Sulfide (VMS)-type deposits in Group-I with the dominant mineralized host rocks in Group-II.
The following diagram shows phase relations in a system consisting of components A and B at 1 bar pressure. If the initial composition of liquid is R, during cooling and crystallization of magma, which of the following statement(s) is/are CORRECT?
The sand supply and the variability of wind direction result in different dune types. In the options below, choose the CORRECT pair of dune types marked I and II in the figure.
Identify the common metamorphic minerals labelled X and Y in the ACF diagram.
If the shrinkage factor of a crude oil is 0.7, its formation volume factor is ________. \text{[round off to 1 decimal place]}
A mineral of uniform composition is cut into a wedge shape. The birefringence of the wedge section is 0.012. The retardation at 40 µm thickness of the wedge is ________ nm. \text{[in integer]}
A radioactive nucleus \( {}^{290}_{92}X \) decays to \( {}^{278}_{87}Y \). The number of \( \alpha \) and \( \beta \) particles emitted during this decay are
In the geological map of India, which one of the following geological units has the largest area?
A coarse-grained igneous rock consists of 55% olivine, 25% augite, and 20% enstatite. According to the IUGS classification, the rock is
The rock-type used to build the walls of the Red Fort in Delhi is

A mantle source rock melts at a time to giving rise to melt (M) and residue (R). Which of the following statements is CORRECT about evolution of the \(( ^{143}Nd/^{144}Nd )\) and \(( ^{87}Sr/^{86}Sr )\) isotope ratio in M (that crystallized to form a rock) and R?

Match the items in Group-I with corresponding appropriate items in Group-II. 
Group-I                        Group-II
P. Cs                           1. Siderophile 
Q. Au                         2. Chalophile 
R. Cd                          3. Atmophile 
S. Rn                          4. Lithophile