The age of most ancient geological formations is estimated by a)`C-14` dating method b)`K-Ag` method c)`U-Pb` method d)`Ra-Rn` method

Options

A. potassium argon method
B. carbon 14 dating method `
C. radium silicon method
D. uranium lead method

Explanation

To solve the question regarding the method used to estimate the age of most ancient geological formations, we can analyze each option provided.

1. **Understanding the Options**:
- **a) C-14 dating method**: This method is primarily used for dating organic materials and is effective for samples that are up to about 50,000 years old.
- **b) K-Ag method**: This option seems to be a misrepresentation. The potassium-argon (K-Ar) dating method is used for dating volcanic rocks and is effective for much older geological formations.
- **c) U-Pb method**: The uranium-lead dating method is one of the oldest and most reliable radiometric dating methods, used for dating the oldest rocks on Earth, often over a billion years old.
- **d) Ra-Rn method**: This option refers to radium and radon, which are not commonly used for dating geological formations.

2. **Analyzing the Most Suitable Method**:
- Given that the question asks for the age of "most ancient geological formations," we need to focus on methods that can date rocks that are millions to billions of years old.
- The **U-Pb method** (option c) is particularly well-suited for this purpose, as it can date zircon crystals found in igneous rocks, which are often billions of years old.

3. **Conclusion**:
- After analyzing the options, the most appropriate method for estimating the age of ancient geological formations is the **U-Pb method** (option c).

Therefore, the answer is:
**c) U-Pb method**

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