Preprints
https://doi.org/10.5194/egusphere-2022-74
https://doi.org/10.5194/egusphere-2022-74
 
 | Highlight paper
25 Mar 2022
25 Mar 2022

Shallow marine carbonates as recorders of orbitally induced past climate changes – example from the Oxfordian of the Swiss Jura Mountains

André Strasser André Strasser
  • Department of Geosciences, University of Fribourg, Fribourg, 1700, Switzerland

Abstract. The detailed analysis of shallow marine carbonate sections in the Swiss Jura Mountains allows interpreting the climate changes that affected the sedimentary system during the middle to late Oxfordian (Late Jurassic). The sediments formed on a subtropical platform where carbonate-producing organisms proliferated, and ooids and oncoids were common. The sections are composed of hierarchically stacked elementary, small-scale, and medium-scale depositional sequences where facies changes imply deepening-shallowing trends. The major sequence boundaries Ox 6, Ox 7, and Ox 8 can be correlated with those of other European basins and place the studied sections in a broader framework. The chronostratigraphic tie points imply that the medium- and small-scale sequences formed in tune with the orbital eccentricity cycles of 405 and 100 kyr, respectively, and the elementary sequences with the precession cycle of 20 kyr. Orbitally controlled insolation changes at the top of the atmosphere translated into climate changes: low insolation generally resulted in low sea level amplitudes at the 20 kyr frequency, and in a cool and humid climate at the palaeolatitude of the Jura platform. Terrigenous material was eroded from the hinterland and distributed over the platform. High insolation led to sea level rise to create accommodation, and to warm and semiarid to arid conditions in which coral reefs could grow. However, nutrient input favoured growth of microbialites that encrusted the corals. The reconstruction of high-frequency sea level fluctuations based on facies analysis compares well with the curve of insolation changes calculated for the past 500 kyr. It is therefore assumed that sea level fluctuations were mainly due to thermal expansion and retraction of ocean surface water. Two models are presented that explain the formation of elementary sequences, one for low and one for high insolation. Despite the important lateral facies variations typical of a shallow marine platform, and despite the uncertainties in the reconstruction of sea level changes, this study demonstrates the potential of carbonate ecosystems to record past climate changes at a time resolution of 20’000 years. Relatively short time windows can thus be opened in the deep geologic past, and processes and products there can be compared with those of the Holocene and the Recent. For example, it appears that today’s anthropogenically induced sea level rise is more than ten times faster than the fastest rise reconstructed for the Oxfordian.

Journal article(s) based on this preprint

14 Sep 2022
| Highlight paper
Shallow marine carbonates as recorders of orbitally induced past climate changes – example from the Oxfordian of the Swiss Jura Mountains
André Strasser
Clim. Past, 18, 2117–2142, https://doi.org/10.5194/cp-18-2117-2022,https://doi.org/10.5194/cp-18-2117-2022, 2022
Short summary

André Strasser

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-74', Marc Aurell, 19 May 2022
    • AC1: 'Reply on RC1', André Strasser, 19 May 2022
  • RC2: 'Comment on egusphere-2022-74', Simon Andrieu, 17 Jun 2022
    • AC2: 'Reply on RC2', André Strasser, 19 Jun 2022

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-74', Marc Aurell, 19 May 2022
    • AC1: 'Reply on RC1', André Strasser, 19 May 2022
  • RC2: 'Comment on egusphere-2022-74', Simon Andrieu, 17 Jun 2022
    • AC2: 'Reply on RC2', André Strasser, 19 Jun 2022

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision
ED: Publish subject to minor revisions (review by editor) (03 Aug 2022) by Denis-Didier Rousseau
AR by André Strasser on behalf of the Authors (04 Aug 2022)  Author's response    Author's tracked changes    Manuscript
ED: Publish as is (09 Aug 2022) by Denis-Didier Rousseau
AR by André Strasser on behalf of the Authors (09 Aug 2022)  Author's response    Manuscript

Journal article(s) based on this preprint

14 Sep 2022
| Highlight paper
Shallow marine carbonates as recorders of orbitally induced past climate changes – example from the Oxfordian of the Swiss Jura Mountains
André Strasser
Clim. Past, 18, 2117–2142, https://doi.org/10.5194/cp-18-2117-2022,https://doi.org/10.5194/cp-18-2117-2022, 2022
Short summary

André Strasser

André Strasser

Viewed

Total article views: 392 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
276 93 23 392 10 10
  • HTML: 276
  • PDF: 93
  • XML: 23
  • Total: 392
  • BibTeX: 10
  • EndNote: 10
Views and downloads (calculated since 25 Mar 2022)
Cumulative views and downloads (calculated since 25 Mar 2022)

Viewed (geographical distribution)

Total article views: 361 (including HTML, PDF, and XML) Thereof 361 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 14 Sep 2022
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

The paper presents an interesting review of deep time ecosystems and suggests that the interpretation of the evolution of ancient sedimentary systems can be refined and better compared to today’s changes in ecosystems. Concerning the rate of climate change, this study implies that anthropogenically induced global warming and subsequent sea level rise today occurs more than ten times faster than the fastest rise reconstructed for the Oxfordian (159 Ma - 154 Ma)
Short summary
Some 155 million years ago, sediments were deposited in a shallow, subtropical sea. Coral reefs formed in a warm and arid climate during high sea level, clays were washed into the ocean at low sea level and when it rained. Climate and sea level changes were induced by cyclical insolation changes. Analysing the sedimentary record, it appears that sea level rise today (as a result of global warming) is more than ten times faster than the fastest rise reconstructed from the geologic past.