U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland
<p>Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, res...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-11-01
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| Series: | Solid Earth |
| Online Access: | https://se.copernicus.org/articles/12/2539/2021/se-12-2539-2021.pdf |
| _version_ | 1818567463673004032 |
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| author | L. Smeraglia L. Smeraglia L. Smeraglia N. Looser O. Fabbri F. Choulet M. Guillong S. M. Bernasconi |
| author_facet | L. Smeraglia L. Smeraglia L. Smeraglia N. Looser O. Fabbri F. Choulet M. Guillong S. M. Bernasconi |
| author_sort | L. Smeraglia |
| collection | DOAJ |
| description | <p>Foreland fold-and-thrust belts (FTBs) record long-lived
tectono-sedimentary activity, from passive margin sedimentation, flexuring,
and further evolution into wedge accretion ahead of an advancing orogen.
Therefore, dating fault activity is fundamental for plate movement
reconstruction, resource exploration, and earthquake hazard assessment. Here,
we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts
and three tear faults sampled at the regional scale across the Jura
fold-and-thrust belt in the northwestern Alpine foreland (eastern France).
Three regional tectonic phases are recognized in the middle Eocene–Pliocene
interval: (1) pre-orogenic faulting at <span class="inline-formula">48.4±1.5</span> and <span class="inline-formula">44.7±2.6</span> Ma associated with the far-field effect of the Alpine or Pyrenean compression,
(2) syn-orogenic thrusting at <span class="inline-formula">11.4±1.1</span>, <span class="inline-formula">10.6±0.5</span>, <span class="inline-formula">9.7±1.4</span>, <span class="inline-formula">9.6±0.3</span>, and <span class="inline-formula">7.5±1.1</span> Ma associated with the
formation of the Jura fold-and-thrust belt with possible in-sequence thrust
propagation, and (3) syn-orogenic tear faulting at <span class="inline-formula">10.5±0.4</span>, <span class="inline-formula">9.1±6.5</span>, <span class="inline-formula">5.7±4.7</span>, and at <span class="inline-formula">4.8±1.7</span> Ma including the
reactivation of a pre-orogenic fault at <span class="inline-formula">3.9±2.9</span> Ma. Previously
unknown faulting events at <span class="inline-formula">48.4±1.5</span> and <span class="inline-formula">44.7±2.6</span> Ma predate the reported late Eocene age for tectonic activity
onset in the Alpine foreland by <span class="inline-formula">∼10</span> Myr. In addition, we date the previously inferred
reactivation of pre-orogenic strike-slip faults as tear faults during Jura
imbrication. The U–Pb ages document a minimal time frame for the evolution
of the Jura FTB wedge by possible in-sequence thrust imbrication above the
low-friction basal decollement consisting of evaporites.</p> |
| first_indexed | 2024-12-14T06:23:44Z |
| format | Article |
| id | doaj.art-c6a5ea595903400a9389d0f0545c4916 |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-12-14T06:23:44Z |
| publishDate | 2021-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-c6a5ea595903400a9389d0f0545c49162022-12-21T23:13:44ZengCopernicus PublicationsSolid Earth1869-95101869-95292021-11-01122539255110.5194/se-12-2539-2021U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine forelandL. Smeraglia0L. Smeraglia1L. Smeraglia2N. Looser3O. Fabbri4F. Choulet5M. Guillong6S. M. Bernasconi7National Research Council, IGAG, Rome, ItalyChrono-Environnement, UMR 6249, Université de Bourgogne-Franche Comté, 25000 Besançon, Franceformerly at: Dipartimento di Scienze della Terra, Sapienza Università di Roma, P.le Aldo Moro 5, 00185, Rome, ItalyGeological Institute, ETH Zürich, Sonneggstrasse 5, 8092 Zurich, SwitzerlandChrono-Environnement, UMR 6249, Université de Bourgogne-Franche Comté, 25000 Besançon, FranceChrono-Environnement, UMR 6249, Université de Bourgogne-Franche Comté, 25000 Besançon, FranceGeological Institute, ETH Zürich, Sonneggstrasse 5, 8092 Zurich, SwitzerlandGeological Institute, ETH Zürich, Sonneggstrasse 5, 8092 Zurich, Switzerland<p>Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, and earthquake hazard assessment. Here, we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts and three tear faults sampled at the regional scale across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Three regional tectonic phases are recognized in the middle Eocene–Pliocene interval: (1) pre-orogenic faulting at <span class="inline-formula">48.4±1.5</span> and <span class="inline-formula">44.7±2.6</span> Ma associated with the far-field effect of the Alpine or Pyrenean compression, (2) syn-orogenic thrusting at <span class="inline-formula">11.4±1.1</span>, <span class="inline-formula">10.6±0.5</span>, <span class="inline-formula">9.7±1.4</span>, <span class="inline-formula">9.6±0.3</span>, and <span class="inline-formula">7.5±1.1</span> Ma associated with the formation of the Jura fold-and-thrust belt with possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at <span class="inline-formula">10.5±0.4</span>, <span class="inline-formula">9.1±6.5</span>, <span class="inline-formula">5.7±4.7</span>, and at <span class="inline-formula">4.8±1.7</span> Ma including the reactivation of a pre-orogenic fault at <span class="inline-formula">3.9±2.9</span> Ma. Previously unknown faulting events at <span class="inline-formula">48.4±1.5</span> and <span class="inline-formula">44.7±2.6</span> Ma predate the reported late Eocene age for tectonic activity onset in the Alpine foreland by <span class="inline-formula">∼10</span> Myr. In addition, we date the previously inferred reactivation of pre-orogenic strike-slip faults as tear faults during Jura imbrication. The U–Pb ages document a minimal time frame for the evolution of the Jura FTB wedge by possible in-sequence thrust imbrication above the low-friction basal decollement consisting of evaporites.</p>https://se.copernicus.org/articles/12/2539/2021/se-12-2539-2021.pdf |
| spellingShingle | L. Smeraglia L. Smeraglia L. Smeraglia N. Looser O. Fabbri F. Choulet M. Guillong S. M. Bernasconi U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland Solid Earth |
| title | U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland |
| title_full | U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland |
| title_fullStr | U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland |
| title_full_unstemmed | U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland |
| title_short | U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland |
| title_sort | u pb dating of middle eocene pliocene multiple tectonic pulses in the alpine foreland |
| url | https://se.copernicus.org/articles/12/2539/2021/se-12-2539-2021.pdf |
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