meteorites
Geology Mineralogy MCQ Solution: Identifying Correct Statements
This multiple-choice question asks us to identify the single correct statement about specific minerals and geological terms from the options provided. Let's analyze each statement in detail.
Statement 1: Pyroxene is commonly found in meteorites
Pyroxenes are a significant group of silicate minerals, characterized by single chains of silica tetrahedra. They are essential components of many igneous rocks, especially mafic and ultramafic ones, and are also found in metamorphic rocks. Their presence is widespread in the Earth's crust and mantle.
Regarding meteorites, various types contain pyroxenes. For instance, chondrites, which are primitive meteorites, often show abundant pyroxene minerals. Their composition in meteorites helps scientists understand the conditions under which these extraterrestrial materials formed and evolved.
Conclusion: This statement is factually correct.
Statement 2: Amphiboles form about 20% of the Earth's crust
Amphiboles are another group of silicate minerals, distinguished by their double-chain structure and the presence of hydroxyl ions (OH). They are common constituents of igneous and metamorphic rocks, often occurring alongside pyroxenes.
However, the abundance of amphiboles in the Earth's crust is significantly less than 20%. Feldspars are the most abundant mineral group, making up roughly 50% of the crust, followed by quartz (about 12%). Amphiboles constitute a smaller fraction, generally estimated to be less than 10% of the Earth's crust by volume.
Conclusion: This statement is incorrect.
Statement 3: Quartz is soluble in water
Quartz is a mineral composed of silicon dioxide (SiO2). It is extremely common, forming the basis of many rocks like granite and sandstone. It is known for its hardness and chemical stability.
Quartz exhibits very low solubility in pure water under standard surface conditions. While it can undergo very slow chemical weathering over geological time or dissolve under specific conditions (like high temperature, pressure, or in the presence of certain aggressive chemical agents like strong alkaline solutions), it is considered practically insoluble in everyday water.
Conclusion: This statement is incorrect.
Statement 4: The word 'sedimentary' is derived from the Latin word kelimentum
Sedimentary rocks are formed through the process of sedimentation, where particles like sand, silt, and clay accumulate and are later cemented together.
The term 'sedimentary' originates from the Latin word 'sedimentum', which means 'a settling' or 'sediment'. The Latin word 'elementum' means 'first principle' or 'rudiment'. Thus, the statement incorrectly cites the origin of the word 'sedimentary'.
Conclusion: This statement is incorrect.
Final Conclusion
After evaluating each option based on established geological facts, the only statement that accurately describes the subject matter is that pyroxene is commonly found in meteorites.
Similar Questions
Which one among the following statements with reference to the black cotton soils of India is NOT correct?
Which one of the following is an example of both an igneous as well as a metamorphic rock?
Which one of the following is found in appreciable amount in Laterite soil in India?
- Loose sediments are transformed into sedimentary rocks by the process of
- Quartzite is metamorphosed from which one of the following rocks?
Important Questions from Rocks and Soils
Soil, in which nearly all our food grows, is a living resource that takes years to form. Yet it can vanish in minutes. Each year 75 billion tonnes of fertile soil is lost to erosion. That is alarming — and not just for food producers. Soil can trap huge quantities of carbon dioxide in the form of organic carbon and prevent it from escaping into the atmosphere.
On the basis of the above passage, the following assumptions have been made :
1. Large scale soil erosion is a major reason for widespread food insecurity in the world.
2. Soil erosion is mainly anthropogenic.
3. Sustainable management of soils helps in combating climate change.
Which of the above assumptions is/are valid ?
With reference to agricultural soils, consider the following statements :
1. A high content of organic matter in soil drastically reduces its water holding capacity.
2. Soil does not play any role in the sulphur cycle.
3. Irrigation over a period of time can contribute to the salinization of some agricultural lands.
Which of the statements given above is/are correct ?
Which of the following statements regarding laterite soils of India are correct?
1. They are generally red in colour.
2. They are rich in nitrogen and potash.
3. They are well-developed in Rajasthan and UP.
4. Tapioca and cashew nuts grow well on these soils.
Select the correct answer using the codes given below:
Which of the following adds/add nitrogen to the soil?
1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation
Select the correct answer using the codes given below:
When you travel in certain parts of India, you will notice red soil. What is the main reason for this colour ?
