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High-resolution Late Silurian correlations between Gotland, Sweden and the Broken River region, NE Australia: Lithologies, conodonts and isotopes

Jeppsson, Lennart LU ; Talent, J. A. ; Mawson, R. ; Simpson, A. J. ; Andrew, A. S. ; Calner, M. ; Whitford, D. J. ; Trotter, J. A. ; Sandstrom, O. and Caldon, H. J. (2007) International Symposium on Early Palaeozoic Palaeogeography and Palaeoclimate 245(1-2). p.115-137
Abstract
High-resolution correlations, partly with a precision better than 10 ka, are achieved between late Ludfordian sequences on Gotland, Sweden (on Baltica), and a section (COG) through the Coral Gardens Formation along the Broken River, northeastern Australia (on Gondwana), despite these sections having been on different palaeocontinents facing different oceans. The interval is characterised by rapid, very large faunal, isotopic, and lithologic changes. Lithologies are remarkably similar in the two areas, consisting of, in order from below: marls with thin limestone beds, flaggy limestones, oncoidal crinoidal limestone, oncoidal marls, terrigenous clastics (silty clay, mudstone, sandstone), oolite, and cliff-/gorge-forming limestones. Further,... (More)
High-resolution correlations, partly with a precision better than 10 ka, are achieved between late Ludfordian sequences on Gotland, Sweden (on Baltica), and a section (COG) through the Coral Gardens Formation along the Broken River, northeastern Australia (on Gondwana), despite these sections having been on different palaeocontinents facing different oceans. The interval is characterised by rapid, very large faunal, isotopic, and lithologic changes. Lithologies are remarkably similar in the two areas, consisting of, in order from below: marls with thin limestone beds, flaggy limestones, oncoidal crinoidal limestone, oncoidal marls, terrigenous clastics (silty clay, mudstone, sandstone), oolite, and cliff-/gorge-forming limestones. Further, independent correlation dates several of the lithological changes as coeval. The 813 C excursion in whole rock carbonates is one of the three largest ones known during the Phanerozoic. The increase in delta C-13 is very similar in the two areas, from below + 1 parts per thousand to c. + 9 parts per thousand VPDB though two Gotland samples yielded + 9.71 parts per thousand and + 10.54 parts per thousand (the corresponding COG interval included fewer carbonate layers than needed to definitely exclude that this difference is due to a lack of suitable rocks for sampling). Compared with the lithologies and the delta C-13 curves, the conodont faunas display some divergence, but key taxa permit precise correlations for much of the studied interval. The conodont assemblages change stepwise from very diverse in the Polygnathoides siluricus Zone to a low diversity fauna dominated markedly by a single taxon (Upper Icriodontid Subzone), returning abruptly to a comparatively diverse Ozarkodina snajdri Zone fauna. A method resembling graphic correlation in some respects is used to propose a similarly high-resolution correlation through a longer interval for future testing. (c) 2006 Elsevier B.V. All rights reserved. (Less)
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author
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organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
high-resolution correlation, conodonts, carbon isotopes, Australia, Silurian, Sweden
host publication
Palaeogeography, Palaeoclimatology, Palaeoecology
volume
245
issue
1-2
pages
115 - 137
publisher
Elsevier
conference name
International Symposium on Early Palaeozoic Palaeogeography and Palaeoclimate
conference location
Erlangen, Germany
conference dates
2004-09-01 - 2004-09-03
external identifiers
  • wos:000245163300009
  • scopus:33847047925
ISSN
0031-0182
1872-616X
DOI
10.1016/j.palaeo.2006.02.032
language
English
LU publication?
yes
id
91108441-16ac-442b-b826-e74e381857fd (old id 1416995)
date added to LUP
2016-04-01 11:48:51
date last changed
2024-05-06 18:05:52
@inproceedings{91108441-16ac-442b-b826-e74e381857fd,
  abstract     = {{High-resolution correlations, partly with a precision better than 10 ka, are achieved between late Ludfordian sequences on Gotland, Sweden (on Baltica), and a section (COG) through the Coral Gardens Formation along the Broken River, northeastern Australia (on Gondwana), despite these sections having been on different palaeocontinents facing different oceans. The interval is characterised by rapid, very large faunal, isotopic, and lithologic changes. Lithologies are remarkably similar in the two areas, consisting of, in order from below: marls with thin limestone beds, flaggy limestones, oncoidal crinoidal limestone, oncoidal marls, terrigenous clastics (silty clay, mudstone, sandstone), oolite, and cliff-/gorge-forming limestones. Further, independent correlation dates several of the lithological changes as coeval. The 813 C excursion in whole rock carbonates is one of the three largest ones known during the Phanerozoic. The increase in delta C-13 is very similar in the two areas, from below + 1 parts per thousand to c. + 9 parts per thousand VPDB though two Gotland samples yielded + 9.71 parts per thousand and + 10.54 parts per thousand (the corresponding COG interval included fewer carbonate layers than needed to definitely exclude that this difference is due to a lack of suitable rocks for sampling). Compared with the lithologies and the delta C-13 curves, the conodont faunas display some divergence, but key taxa permit precise correlations for much of the studied interval. The conodont assemblages change stepwise from very diverse in the Polygnathoides siluricus Zone to a low diversity fauna dominated markedly by a single taxon (Upper Icriodontid Subzone), returning abruptly to a comparatively diverse Ozarkodina snajdri Zone fauna. A method resembling graphic correlation in some respects is used to propose a similarly high-resolution correlation through a longer interval for future testing. (c) 2006 Elsevier B.V. All rights reserved.}},
  author       = {{Jeppsson, Lennart and Talent, J. A. and Mawson, R. and Simpson, A. J. and Andrew, A. S. and Calner, M. and Whitford, D. J. and Trotter, J. A. and Sandstrom, O. and Caldon, H. J.}},
  booktitle    = {{Palaeogeography, Palaeoclimatology, Palaeoecology}},
  issn         = {{0031-0182}},
  keywords     = {{high-resolution correlation; conodonts; carbon isotopes; Australia; Silurian; Sweden}},
  language     = {{eng}},
  number       = {{1-2}},
  pages        = {{115--137}},
  publisher    = {{Elsevier}},
  title        = {{High-resolution Late Silurian correlations between Gotland, Sweden and the Broken River region, NE Australia: Lithologies, conodonts and isotopes}},
  url          = {{http://dx.doi.org/10.1016/j.palaeo.2006.02.032}},
  doi          = {{10.1016/j.palaeo.2006.02.032}},
  volume       = {{245}},
  year         = {{2007}},
}