Radiolarian microfossils, tiny, siliceous, single-celled organisms, make for excellent timekeepers. Think of them as the world's smallest clocks. These wee fellows have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock, they act like a yardstick, helping geologists accurately date rock from around the globe.
Friday, 25 September 2009
RADIALARIANS: TIMEKEEPERS OF ANCIENT SEAS
Radiolarian microfossils, tiny, siliceous, single-celled organisms, make for excellent timekeepers. Think of them as the world's smallest clocks. These wee fellows have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock, they act like a yardstick, helping geologists accurately date rock from around the globe.