Microtectites 95
from pelagic sediments, typically several per gram pelagic clay. Because it was
thought that they represent a steady influx of matter from space, their abundance was
used occasionally as an indicator for accumulation rates.
Glassy objects, normally up to 1 mm in diameter, may be produced by meteorite
impacts on terrestrial rocks and are called "microtectites". They were found in deepsea sediments in strewn fields around Austmlasia (0.7 million years old), off the
Ivory coast (1.1 million years), and in the Caribbean (33-35 million years), for
example. Where abundant, they can be used as a time marker and serve for correlation by "event stratigraphy".
Further Reading
Selley RC (1976) An introduction to sedimentology. Academic Press, London
Bouma AG, Normark WR, Barnes NE (eds) (1985) Submarine fans and related turbidite systems.
Springer, Berlin Heidelberg New York
Reading HG (ed) (1986) Sedimentary environments and facies. Blackwell Scientific, Oxford
Tucker ME, Wright VP (1990) Carbonate sedimentology. Blackwell Scientific, Oxford
Friedman GM, Sanders JE, Kopaska-Merkel DC (1992) Principles of sedimentary deposits. Stratigraphy and sedimentology. Macmillan, New York
from pelagic sediments, typically several per gram pelagic clay. Because it was
thought that they represent a steady influx of matter from space, their abundance was
used occasionally as an indicator for accumulation rates.
Glassy objects, normally up to 1 mm in diameter, may be produced by meteorite
impacts on terrestrial rocks and are called "microtectites". They were found in deepsea sediments in strewn fields around Austmlasia (0.7 million years old), off the
Ivory coast (1.1 million years), and in the Caribbean (33-35 million years), for
example. Where abundant, they can be used as a time marker and serve for correlation by "event stratigraphy".
Further Reading
Selley RC (1976) An introduction to sedimentology. Academic Press, London
Bouma AG, Normark WR, Barnes NE (eds) (1985) Submarine fans and related turbidite systems.
Springer, Berlin Heidelberg New York
Reading HG (ed) (1986) Sedimentary environments and facies. Blackwell Scientific, Oxford
Tucker ME, Wright VP (1990) Carbonate sedimentology. Blackwell Scientific, Oxford
Friedman GM, Sanders JE, Kopaska-Merkel DC (1992) Principles of sedimentary deposits. Stratigraphy and sedimentology. Macmillan, New York