Question

A continuous 10 m thick sequence of shale was deposited in 10,000 years at uniform rate of sedimentation. The number of samples that must be collected at equal stratigraphic intervals to sample the succession every 500 years is .............. .

Hint:

To determine the number of samples, divide the total time period by the sampling interval.

Answer 1

Correct Answer: 20

Step 1: Understanding the deposition rate.
The shale sequence has a thickness of 10 m, and it was deposited over 10,000 years, implying a uniform rate of deposition. The rate of deposition is: \[ \text{Deposition rate} = \frac{10 \, \text{m}}{10000 \, \text{years}} = 0.001 \, \text{m/year} \]

Step 2: Calculating the number of samples.
To collect samples every 500 years, we need to calculate the number of 500-year intervals in the 10,000-year period: \[ \text{Number of samples} = \frac{10000 \, \text{years}}{500 \, \text{years/sample}} = 20 \, \text{samples} \]

Step 3: Conclusion.
The number of samples that must be collected is 20.