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  • Print publication year: 2013
  • Online publication date: December 2013

7 - Biostratigraphy

Summary

This chapter deals with biostratigraphy. It contains sections on Foraminifera in biostratigraphy; on the Palaeozoic, Mesozoic and Cenozoic; on biostratigraphic and associated visualisation technologies; and on stratigraphic time-scales.

Biostratigraphy

Biostratigraphy involves the use of fossils in the ordering of the rock record in time (Jones, 1996, 2006, 2011a; see also McGowran, 2005). It relies on William Smith’s fundamental ‘Law of Strata Identified by Organised Fossils’, which posits that particular ages of rock, regardless of facies, can be characterised at any given locality, and correlated from one locality to another, by means of index or marker fossils (see below). Like palaeoenvironmental interpretation, it can be impaired by natural, taphonomic, factors or biases; and also by artificial factors or biases, such as species identification bias, or subjectivity and inaccuracy in the identification of species, in turn leading to interpretation bias (see, for example, Ginsburg, 1997; see also Sections 2.3, 2.4 and 3.2.1).

Biostratigraphy has widespread applications in academia, in field geology, and in marine geology. It is and has long been critical to field geological mapping, for example that undertaken by the British Geological Survey in the British Isles (Wilkinson, 2011), and, in collaboration with local surveys, overseas, as in the Borbon, Manabi and Progreso basins in Ecuador (Whittaker, 1988). It makes extensive use both of macrofossils, which can be identified in the field, and also of microfossils such as Foraminifera, which are generally identified in the laboratory (note in this context, though, that certain microfossils, such as Larger Benthic Foraminifera (LBFs) are sufficiently large as to be identifiable as least to generic level in hand specimen in the field, for example, larger Fusulinida in the Permian of New Mexico and west Texas in the south-western United States; larger agglutinating Foraminifera in the Cretaceous of the Middle East; and larger Miliolida and Rotaliida in the Palaeogene of the Middle East, north Africa, northern South America and the Caribbean, and the Pyrenees, and in the Neogene of the Far East). In the field and/or in the laboratory, it assists not only in the characterisation of age and in correlation but also in the construction of an integrated tectono-sequence stratigraphic framework, and in the constraint of tectonic evolution, for example in the constraint of the collision-related uplift in the Miocene–Pliocene of Timor, by means of detailed palaeobathymetric interpretation (Haig, 2012).