Which of the following biogeochemical cycle has a major reservoir in sedimentary rock :-

Options

A. carbon cycle
B. Nitrogen cycle
C. phosphorus cycle
D. Water cycle

Answer

To determine which biogeochemical cycle has a major reservoir in sedimentary rock, we can analyze each of the options provided:

### Step 1: Understand the Biogeochemical Cycles
- **Carbon Cycle**: Involves the movement of carbon among the atmosphere, oceans, soil, and living organisms. Major reservoirs include the atmosphere and ocean, not primarily sedimentary rock.

- **Nitrogen Cycle**: Involves the transformation of nitrogen in various forms. Major reservoirs include the atmosphere and soil, but not sedimentary rock.

- **Phosphorus Cycle**: This cycle is unique because it does not have a gaseous phase. The major reservoir for phosphorus is found in sedimentary rocks, where it is stored in the form of phosphate.

- **Water Cycle**: Involves the continuous movement of water in various forms (liquid, vapor, ice) through the atmosphere, hydrosphere, and lithosphere. It does not have a major reservoir in sedimentary rock.

### Step 2: Identify the Major Reservoir
From the analysis:
- The **phosphorus cycle** is the only cycle that has a major reservoir in sedimentary rocks.

### Step 3: Conclusion
Thus, the correct answer to the question is the **phosphorus cycle**.

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