Conference PaperPDF Available

Abstract

The study of astronomical climate forcing and the application of cyclostratigraphy have experienced a spectacular growth over the last decades. In the field of cyclostratigraphy a broad range in methodological approaches exist. However, comparative study between the different approaches is lacking. Different cases demand different approaches, but with the growing importance of the field, questions arise about reproducibility, uncertainties and standardization of results. The radioisotopic dating community, in particular, has done far-reaching efforts to improve reproducibility and intercomparison of radioisotopic dates and their errors. To satisfy this need in cyclostratigraphy, we initiate a comparable framework for the community. The aims are to investigate and quantify reproducibility of, and uncertainties related to cyclostratigraphic studies and to provide a platform to discuss the merits and pitfalls of different methodologies, and their applicabilities. With this poster, we ask the feedback from the community on how to design this comparative framework in a useful, meaningful and productive manner. In parallel, we would like to discuss how reproducibility should be tested and what uncertainties should stand for in cyclostratigraphy. On the other hand, we intend to trigger interest for a cyclostratigraphic intercomparison project. This intercomparison project would imply the analysis of artificial and genuine geological records by individual researchers. All participants would be free to determine their method of choice. However, a handful of criterions will be required for an outcome to be comparable. The different results would be compared (e.g. during a workshop or a special session), and the lessons learned from the comparison could potentially be reported in a review paper. The aim of an intercomparison project is not to rank the different methods according to their merits, but to get insight into which specific methods are most suitable for which specific problems, and obtain more information on different sources of uncertainty. As this intercomparison project should be supported by the broader cyclostratigraphic community, we open the floor for suggestions, ideas and practical remarks.
Geophysical Research Abstracts
Vol. 19, EGU2017-9484, 2017
EGU General Assembly 2017
© Author(s) 2017. CC Attribution 3.0 License.
Reproducibility in cyclostratigraphy: initiating an intercomparison
project
Matthias Sinnesael (1), David De Vleeschouwer (1,2), Christian Zeeden (3), and Philippe Claeys (1)
(1) AMGC, Vrije Universiteit Brussel, Brussels, Belgium (matthias.sinnesael@vub.be), (2) MARUM, Center for Marine
Environmental Science, Bremen, Germany, (3) Chair of Physical Geography and Geoecology, RWTH Aachen University,
Aachen, Germany
The study of astronomical climate forcing and the application of cyclostratigraphy have experienced a spectacular
growth over the last decades. In the field of cyclostratigraphy a broad range in methodological approaches
exist. However, comparative study between the different approaches is lacking. Different cases demand different
approaches, but with the growing importance of the field, questions arise about reproducibility, uncertainties
and standardization of results. The radioisotopic dating community, in particular, has done far-reaching efforts
to improve reproducibility and intercomparison of radioisotopic dates and their errors. To satisfy this need in
cyclostratigraphy, we initiate a comparable framework for the community. The aims are to investigate and quantify
reproducibility of, and uncertainties related to cyclostratigraphic studies and to provide a platform to discuss the
merits and pitfalls of different methodologies, and their applicabilities.
With this poster, we ask the feedback from the community on how to design this comparative framework
in a useful, meaningful and productive manner. In parallel, we would like to discuss how reproducibility should
be tested and what uncertainties should stand for in cyclostratigraphy. On the other hand, we intend to trigger
interest for a cyclostratigraphic intercomparison project. This intercomparison project would imply the analysis
of artificial and genuine geological records by individual researchers. All participants would be free to determine
their method of choice. However, a handful of criterions will be required for an outcome to be comparable. The
different results would be compared (e.g. during a workshop or a special session), and the lessons learned from the
comparison could potentially be reported in a review paper. The aim of an intercomparison project is not to rank
the different methods according to their merits, but to get insight into which specific methods are most suitable for
which specific problems, and obtain more information on different sources of uncertainty. As this intercomparison
project should be supported by the broader cyclostratigraphic community, we open the floor for suggestions, ideas
and practical remarks.
... A more conservative use of the term "tuning" refers to the correlation and patternmatching to astronomical solutions only. There are many potential tuning targets in cyclostratigraphy: an astronomical solution that consists of one or more astronomical parameters (Hays et al., 1976;Lourens et al. 1996;Hinnov, 2018a), insolation curves ( Köppen and Wegener, 1924;Milankovitch, 1941;Laskar et al. 2004), glacial models ( Imbrie and Imbrie, 1980), and astronomically tuned stratigraphic reference datasets ( Lisiecki and Raymo, 2005;De Vleeschouwer et al., 2017a). ...
Article
Full-text available
Cyclostratigraphy is an important tool for understanding astronomical climate forcing and reading geological time in sedimentary sequences, provided that an imprint of insolation variations caused by Earth’s orbital eccentricity, obliquity and/or precession is preserved (Milankovitch forcing). Numerous stratigraphic and paleoclimate studies have applied cyclostratigraphy, but the robustness of the methodology and its dependence on the investigator have not been systematically evaluated. We developed the Cyclostratigraphy Intercomparison Project (CIP) to assess the robustness of cyclostratigraphic methods using an experimental design of three artificial cyclostratigraphic case studies with known input parameters. Each case study is designed to address specific challenges that are relevant to cyclostratigraphy. Case 1 represents an offshore research vessel environment, as only a drill-core photo and the approximate position of a late Miocene stage boundary are available for analysis. In Case 2, the Pleistocene proxy record displays clear nonlinear cyclical patterns and the interpretation is complicated by the presence of a hiatus. Case 3 represents a Late Devonian proxy record with a low signal-to-noise ratio with no specific theoretical astronomical solution available for this age. Each case was analyzed by a test group of 17-20 participants, with varying experience levels, methodological preferences and dedicated analysis time. During the CIP 2018 meeting in Brussels, Belgium, the ensuing analyses and discussion demonstrated that most participants did not arrive at a perfect solution, which may be partly explained by the limited amount of time spent on the exercises (~4.5 hours per case). However, in all three cases, the median solution of all submitted analyses accurately approached the correct result and several participants obtained the exact correct answers. Interestingly, systematically better performances were obtained for cases that represented the data type and stratigraphic age that were closest to the individual participants’ experience. This experiment demonstrates that cyclostratigraphy is a powerful tool for deciphering time in sedimentary successions and, importantly, that it is a trainable skill. Finally, we emphasize the importance of an integrated stratigraphic approach and provide flexible guidelines on what good practices in cyclostratigraphy should include. Our case studies provide valuable insight into current common practices in cyclostratigraphy, their potential merits and pitfalls. Our work does not provide a quantitative measure of reliability and uncertainty of cyclostratigraphy, but rather constitutes a starting point for further discussions on how to move the maturing field of cyclostratigraphy forward.
ResearchGate has not been able to resolve any references for this publication.