The structural style at depth of the Umbria-Marche fold-and-thrust belt, which occupies the outer province of the Northern Apennines of peninsular Italy, has long been debated and interpreted in terms of thin-skinned or thick-skinned deforma- tion models, respectively. Thin-skinned models predict that the Mesozoic–Tertiary sedimentary cover was detached along Upper Triassic evaporites and translated northeastward along stepped thrust faults above a relatively undeformed basement. On the other hand, thick-skinned models predict the direct involvement of conspicu- ous basement slices within thrust-related folds. A description of selected examples in the southeastern part of the Umbria-Marche belt reveals that some compressional structures are indeed thin-skinned, their style being controlled by rheological proper- ties of a mechanically heterogeneous stratigraphy containing multiple décollements, whereas other structures are genuinely thick-skinned, their style being dominated by the reverse-reactivation of pre-orogenic normal faults deeply rooted within the basement. Therefore, the contrast of thin- versus thick-skinned structural styles, an issue that has generated a long-lasting debate, is only apparent, since both styles are documented to coexist and to have concurred in controlling the final compressional geometry of the fold-and-thrust belt.

Barchi, M.R., Tavarnelli, E. (2022). Thin vs. thick-skinned tectonics in the Umbria-Marche fold-and-thrust belt: Contrast or coexistence?. In From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez (pp. 71-84). The Geological Society of America [10.1130/2022.2557(05)].

Thin vs. thick-skinned tectonics in the Umbria-Marche fold-and-thrust belt: Contrast or coexistence?

Tavarnelli, Enrico
2022

Abstract

The structural style at depth of the Umbria-Marche fold-and-thrust belt, which occupies the outer province of the Northern Apennines of peninsular Italy, has long been debated and interpreted in terms of thin-skinned or thick-skinned deforma- tion models, respectively. Thin-skinned models predict that the Mesozoic–Tertiary sedimentary cover was detached along Upper Triassic evaporites and translated northeastward along stepped thrust faults above a relatively undeformed basement. On the other hand, thick-skinned models predict the direct involvement of conspicu- ous basement slices within thrust-related folds. A description of selected examples in the southeastern part of the Umbria-Marche belt reveals that some compressional structures are indeed thin-skinned, their style being controlled by rheological proper- ties of a mechanically heterogeneous stratigraphy containing multiple décollements, whereas other structures are genuinely thick-skinned, their style being dominated by the reverse-reactivation of pre-orogenic normal faults deeply rooted within the basement. Therefore, the contrast of thin- versus thick-skinned structural styles, an issue that has generated a long-lasting debate, is only apparent, since both styles are documented to coexist and to have concurred in controlling the final compressional geometry of the fold-and-thrust belt.
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Barchi, M.R., Tavarnelli, E. (2022). Thin vs. thick-skinned tectonics in the Umbria-Marche fold-and-thrust belt: Contrast or coexistence?. In From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez (pp. 71-84). The Geological Society of America [10.1130/2022.2557(05)].
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/1216316