Post-rift extensional tectonics at the edge of a carbonate platform: insights from the Middle Jurassic-Early Cretaceous Monte Giano stratigraphic record (central Apennines, Italy)
| Autor: | Cristina Muraro, Franco Capotorti |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Pelagic Carbonate Platform
Apennines Rift stratigraphic gap Carbonate platform Stratigraphic gap Tectonic phase Geology Unconformity Cretaceous Early Bajocian tectonics Paleontology chemistry.chemical_compound chemistry western Tethys Carbonate platform drowning Carbonate Extensional tectonics Progradation carbonate platform drowning Western Tethys |
| Zdroj: | Geologica Acta; Vol. 19 (2021); 1-22 RCUB. Revistas Científicas de la Universidad de Barcelona Universitat Jaume I Dipòsit Digital de Documents de la UAB Universitat Autònoma de Barcelona |
| ISSN: | 1696-5728 1695-6133 |
| DOI: | 10.1344/geologicaacta2021.19.12 |
| Popis: | A new interpretation of the Middle Jurassic-Early Cretaceous paleogeographic evolution of the NW sector of the Latium-Abruzzi carbonate platform facing the Umbria-Marche Basin is proposed, based on Monte Giano area (central Apennines, Italy). During Late Triassic-early Bajocian time, the area was characterized by shallow water sedimentation. Inner and marginal carbonate platform deposits are overlain by pelagic deposits (Posidonia level), early Bajocian p.p. in age. This unconformity testifying the sudden drowning of the Monte Giano area, while shallow water sedimentation persisted in the remaining sectors of the carbonate platform. The Posidonia level is paraconformably overlain by distal slope deposits of the Velino Gorge limestones Formation, Kimmeridgian p.p.-Tithonian p.p. in age. Therefore, a 12Ma gap is recorded as in the Umbria-Marche Basin pelagic carbonate platforms. An extensional Bajocian tectonic phase, possibly related to the Piemont-Ligurian Ocean opening coupled with rheologic differences at the basin/platform boundary, drastically changed the regional paleogeography causing the breakup and the drowning of the NW sector of the Latium-Abruzzi carbonate platform and the creation of a large flat-topped pelagic carbonate platform. The estimate offset of the early Bajocian fault is around 300-350m. The Velino Gorge limestones fm. pass laterally and vertically to the Upper Tithonian platform-margin reef complex of the Ellipsactinia limestones fm.; these units constitute a shallowing and coarsening upward sequence and levelled the paleobathymetric gradient created by the Bajocian extension. The progradation of the Latium-Abruzzi carbonate platform continued during Early Cretaceous time. These results have strong implications on the tectonic and paleogeographic evolution of the major domains of the central Apennines. |
| Databáze: | OpenAIRE |
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