Which one of the following is NOT an ultramafic rock?
Show Hint
- Wehrlite
- Olivine websterite
- Harzburgite
- Anorthosite
The Correct Option is D
Solution and Explanation
However, anorthosite is not ultramafic. It is a rock primarily composed of plagioclase feldspar, which is a felsic mineral, not a mafic or ultramafic one.
Thus, the correct answer is option (D). Final Answer: \[ \boxed{\text{Anorthosite}} \]
Top Questions on Petrology
- Which one of the following statements is CORRECT for coal?
- Which one of the following is the CORRECT sequence of igneous rocks with increasing SiO2 content?
- In the given isobaric binary temperature-composition (T-X) phase diagram involving solids A and B, the fraction of melt remaining at point Q for a magma having initial composition P will be _______. (Round off to one decimal place)
- Clinopyroxene crystallizing from a basaltic magma has Sm concentration of 24 ppm. If the clinopyroxene-melt partition coefficient for Sm is 1.2, the concentration of Sm in the basaltic magma will be ______ ppm. (In integer)
- Consider the univariant metamorphic reaction Albite = Jadeite + Quartz. The minimum number of chemical components required to describe the composition of all the phases is _________ . (In integer)
Questions Asked in IIT JAM GG exam
Two boreholes A and B, both inclined towards 270°, penetrate a dipping coal bed at the same point and pass through it entirely in the sub-surface as shown in the figure below. The bed dips towards 270°. The thickness of the coal bed, measured along the borehole A is 10 m and along borehole B is 8 m. The angle between the two boreholes is 20°. The orthogonal thickness \( x \) of the coal bed is ........ m. (Round off to one decimal place)
- IIT JAM GG - 2025
- Applied Geology
A well-developed succession of laminated shale is bound by two volcanic ash beds that were precisely dated as shown in the schematic diagram given below. Assuming a constant sedimentation rate, the age of the fossiliferous limestone bed 65 m above the basal volcanic ash bed is ............ Ma. (Round off to nearest integer)
- IIT JAM GG - 2025
- Stratigraphy
The data tabulated below are for flooding events in the last 400 years.
The probability of a large flood accompanied by a glacial lake outburst flood (GLOF) in 2025 is ........... \(\times 10^{-3}\). (Round off to one decimal place)
Year Flood Size Magnitude rank 1625 Large 2 1658 Large + GLOF 1 1692 Small 4 1704 Large 2 1767 Large 2 1806 Small 4 1872 Large + GLOF 1 1909 Large 2 1932 Large 2 1966 Medium 3 2023 Large + GLOF 1 - IIT JAM GG - 2025
- Applied Geology
A satellite launching vehicle is carrying a lander for Moon mapping.
As shown in the figure below, P is the position where the gravitational forces exerted by Earth and Moon on the vehicle balance out.
The distance \( P \) from the center of the Earth is ........... \(\times 10^5\) km. (Round off to two decimal places)
- IIT JAM GG - 2025
- Applied Geology
The isobaric temperature-composition (T–X) phase diagram given below shows the phase relation between components M and N. The equilibrium melting undergone by the rock R to generate the liquid of composition L is .............. % (In integer )
- IIT JAM GG - 2025
- Applied Geology