Calcareous nannofossils
Calcareous nannofossils are a class of tiny (less than 30
History of research
Part of a series related to |
Biomineralization |
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Research of the nannoplankton
The researchers started to use the
Terminology
The terminology in the field evolved over time and nannofossils are also sometimes called "nannoplankton" and "coccoliths" as well as some other names, especially in the literature published in 1950s and 1960s. The term "calcareous nannofossil" was chosen in the DSDP publications (although it was rarely used prior to that) and gained popularity afterwards, in the early 1970s.
Siesser & Haq describe the general use as follows:[12]
- coccolith is restricted by some authors to designate round-shaped elements similar to the ones produced by the living coccolithophores. For differently-shaped objects (e. g., stars and horseshoes), nanolith is being used. Some other authors, however, use coccolith in a broader sense for all calcareous nanofossils;
- nannoplankton is sometimes used to identify the living organisms, with nannofossils referring to the now-extinct species. Other researchers use the nannoplankton for all forms, both living and extinct arguing that even though the true taxonomy of the extinct ones might never be known, their planktic way of living is subject to little doubt.
Siesser & Haq themselves use nannoplankton as a generic way to refer to all organisms, whether living or extinct and nannofossils when describing specifically the fossil forms.
Biostratigraphy
Multiple characteristics of the calcareous nannofossils make them a valuable tool of biostratigraphy and biochronology:[13]
- continuous record from 220 million years ago to present;
- abundance in marine sediments;
- worldwide distribution due to the planktonic nature;
- rapid evolution (with diverse morphology[14]) that provides hundreds of points of appearance and extinction;
- tiny size allows the work to be performed with small samples (less than 1 gramm[14]).
The calcareous nannofossils can be found in the deposits that stretch from the Late Triassic to the modern times. The calcareous nannoplankton biodiversity grew in the Jurassic and Cretaceous periods peaking at about 150 species in the Late Cretaceous.[15]
The boundaries of the biozones in stratigraphy are defined by the biohorizons, points in strata where significant changes in fossil content and distribution occur. Typical events used for biohorizons are: first occurrence, last occurrence, change in abundance of taxons. A combination of biozones arranged in stratigraphical order results in a zonation (or scheme).[10]
The first
The agreed upon stratification reference is codified as Global Boundary Stratotype Section and Point (GSSP) by the International Commission on Stratigraphy. The calcareous nannofossils, with very few exceptions, provide clear biohorizons indicating the positions of the GSSP boundaries in Cenozoic.[16]
Other uses
Calcareous nannofossils are being used in
References
- ^ Romein 1979, p. 7.
- ^ Incarbona et al. 2010, p. 820.
- ^ Siesser & Haq 1987, p. 116.
- ^ a b c d e Siesser & Haq 1987, p. 90.
- ^ a b c Siesser & Haq 1987, p. 87.
- ^ Agnini, Monechi & Raffi 2017, p. 449.
- ^ a b Siesser & Haq 1987, p. 88.
- ^ Siesser 2006, p. 8.
- ^ a b Siesser 2006, p. 10.
- ^ a b Agnini, Monechi & Raffi 2017, p. 452.
- ^ Guilford 1908, p. 822.
- ^ Siesser & Haq 1987, p. 92.
- ^ Agnini, Monechi & Raffi 2017, pp. 448–449.
- ^ a b Falkenberg, Mutterlose & Kaplan 2020, p. 22.
- ^ Falkenberg, Mutterlose & Kaplan 2020, p. 19.
- ^ a b Agnini, Monechi & Raffi 2017, p. 453.
- ^ Falkenberg, Mutterlose & Kaplan 2020, pp. 19–20.
Sources
- Incarbona, A.; Ziveri, P.; Di Stefano, E.; Lirer, F.; Mortyn, G.; Patti, B.; Pelosi, N.; Sprovieri, M.; Tranchida, G.; Vallefuoco, M.; Albertazzi, S.; Bellucci, L. G.; Bonanno, A.; Bonomo, S.; Censi, P.; Ferraro, L.; Giuliani, S.; Mazzola, S.; Sprovieri, R. (17 May 2010), Calcareous nannofossil assemblages from the Central Mediterranean Sea over the last four centuries: the impact of the little ice age, Copernicus GmbH,
- Falkenberg, J.; Mutterlose, J.; Kaplan, U. (16 November 2020). "Calcareous nannofossils in medieval mortar and mortar‐based materials: A powerful tool for provenance analysis". Archaeometry. 63 (1): 19–39. S2CID 228868906.
- Romein, A.J.T. (1979). Lineages in early Paleogene calcareous nannoplankton (PDF). Utrecht Micropaleont. Bull. 22. pp. 1–231.
- Gardin, Silvia; Krystyn, Leopold; Richoz, Sylvain; Barttolini, Annachiara; Galbrun, Bruno (11 May 2012). "Where and when the earliest coccolithophores?". Lethaia. 45 (4): 507–523. ISSN 0024-1164.
- Amos Winter; William G. Siesser, eds. (23 November 2006). "Preface". Coccolithophores. Cambridge University Press. p. ix. ISBN 978-0-521-03169-1.
- Siesser, William G. (23 November 2006). "Historical background of coccolithofore studies". In Amos Winter; William G. Siesser (eds.). Coccolithophores. Cambridge University Press. pp. 1–12. ISBN 978-0-521-03169-1.
- Siesser, William G.; Haq, Bilal U. (1987). "Calcareous Nannoplankton". Notes for a Short Course: Studies in Geology. 18: 87–127. ISSN 0271-1648.
- Agnini, Claudia; Monechi, Simonetta; Raffi, Isabella (23 May 2017). "Calcareous nannofossil biostratigraphy: historical background and application in Cenozoic chronostratigraphy". Lethaia. 50 (3): 447–463. ISSN 0024-1164.
- Guilford, S.H. (1908). "How can we improve our nomenclature?". The Pacific Dental Gazette. XVI (12): 818–823.