The Kinematics of a salt sheet recorded in an array of discorted intrasalt stringers (Les Avellanes Diapir - Sputh-Central Pyrenees)
<p>Stringers represent fragments of competent, brittle layers, formerly interstratified within a layered evaporite</p><p>sequence (LES) that are entrained and deformed by viscous flow. To resolve the impact of the stringers on the</p><p>deformation style of an extrusive...
| Authors: | , , , , , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2023 |
| Country: | España |
| Institution: | Universidad de Barcelona |
| Repository: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/204121 |
| Online Access: | https://hdl.handle.net/2445/204121 |
| Access Level: | Open access |
| Keyword: | Pirineus Estructures sedimentàries Estratigrafia Tectònica salina Pyrenees Sedimentary structures Stratigraphic geology Tectonique du sel |
| Summary: | <p>Stringers represent fragments of competent, brittle layers, formerly interstratified within a layered evaporite</p><p>sequence (LES) that are entrained and deformed by viscous flow. To resolve the impact of the stringers on the</p><p>deformation style of an extrusive salt sheet, an array of decameter-thick, carbonate stringers, preserved in the</p><p>caprock matrix of the Les Avellanes Diapir (South-Central Pyrenees) was analysed. The diapir exposure was</p><p>mapped in detail to produce a cross-section that shows the stringer assemblage. To understand the dynamic</p><p>behaviour of stringers, this natural prototype has been reproduced using scaled analogue models. In the model,</p><p>stringers were carried into the salt sheet, rotating and deforming while migrating toward the sheet front. The</p><p>array of stringers can be divided into the following three structural domains: 1) a feeder domain mainly hosting</p><p>vertical stringers parallel to the stem wall that rotate to a subhorizontal orientation as they approach the</p><p>allochthonous sheet, 2) a sheet domain containing stack-like sets of subvertical and overturned, to subhorizontal</p><p>stringers, as well as isoclinally and recumbently folded stringers, and 3) a sheet front domain characterised by</p><p>stringers dipping toward the salt sheet front. Compartmentalization of the horizontal flow by the transported</p><p>stringers controlled the deformation in the caprock matrix above. Finally, the similarity between the field observations</p><p>and the model is evaluated and discussed to shed light on the Les Avellanes Diapir kinematic evolution.</p> |
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