The significance of Messinian occurrences ofGloborotalia margaritaeandGloborotalia puncticulatain Sicily
作者:
R.W.H. Butler,
H.M. Pedle,
R. Maniscalco,
M. Grasso,
E. McClelland,
B. Finegan,
期刊:
Terra Nova
(WILEY Available online 1996)
卷期:
Volume 8,
issue 1
页码: 59-64
ISSN:0954-4879
年代: 1996
DOI:10.1111/j.1365-3121.1996.tb00725.x
出版商: Blackwell Publishing Ltd
数据来源: WILEY
摘要:
ABSTRACTGloborotalia puncticulataandGloborotalia margaritaeare critical species that define internationally recognized planktonic foraminiferal biozones in the Pliocene. These biozones are defined from stratotype sections on Sicily and their fauna are commonly considered to have been introduced to the Mediterranean after an influx of Atlantic water that terminated the late Miocene desiccation of the basin. Herein new discoveries of these species in rocks that predate the late Miocene desiccation are described. These data are supported by magneto‐ and lithostratigraphy that have been integrated at a single continuous section. Not only do these discoveries question the existing foraminiferal biozone stratigraphy, they also suggest new models for the dispersal of planktonic species. It is proposed thatGloborotalia puncticulataand perhaps evenGloborotalia margaritaeevolved in the Mediterranean during earliest Messinian times (during or before chron C3Bn1n) and dispersed into the Atlantic. This suggests that a marine connection remained between the two sea areas until at least chron C3An.1n. Using the existing geomagnetic polarity time scale, these occurrences are some 2 Myr earlier than previously recorded in the Mediterranean. The distribution ofG. margaritaeand G.puncticulatain Mediterranean sections is likely to reflect palaeoenvironment or the preservation of deposits rather than the absolute age of the sediment
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