If a typical rate for the accumulation of sediments is 1 mm/year, what thickness (metres) of sedimentary rock could accumulate over a period of 30 million years?
Instructor solution
At 1 mm/y, 30,000,000 mm would accumulate over that 30 million years. This is equivalent to 30,000 metres or 30 kilometres. Few sequences of sedimentary rock are even close to that thickness because most sediments accumulate at much lower rates, more like 0.1 millimetre per year.
Physical Geology - 2nd Edition - Chapter 1 - Introduction to Geology (pages 17-20)
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If sediment accumulation occurs at a rate of 0.5 mm/year, what thickness (metres) of sedimentary rock could accumulate over 20 million years?
- A.
At 0.5 mm/year, 20,000,000 mm × 0.5 = 10,000,000 mm or 10,000 metres (10 kilometres).
- B.
At 0.5 mm/year, 20,000,000 mm × 0.1 = 2,000,000 mm or 2,000 metres (2 kilometres).
- C.
At 0.5 mm/year, 20,000,000 mm × 0.2 = 4,000,000 mm or 4,000 metres (4 kilometres).
- D.
At 0.5 mm/year, 20,000,000 mm × 1 = 20,000,000 mm or 20,000 metres (20 kilometres).
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