DOI: 10.1016/j.palaeo.2017.07.025
论文题名: Unravelling the origin of a Paleogene unconformity in the Latium-Abruzzi carbonate succession: A shaved platform
作者: Brandano M.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Carbonate ramp
; Hiatus
; Mediterranean
; Paraconformity
; Wave-base
英文摘要: The Latium-Abruzzi carbonate platform constitutes the sedimentary record from the Triassic to the late Miocene of the southern Tethyan margin outcropping in the Apennines. This sedimentary succession is punctuated by an important hiatus between the end of the Cretaceous and the early Miocene. This Paleogene hiatus has long been interpreted as the result of prolonged subaerial exposure. However, no evidence of such exposure has ever been documented on the Latium-Abruzzi platform. This is contrary to the coeval and adjacent Apulia and Lessini carbonate platforms where a broadly-developed paleokarst system formed between the Eocene and the early Miocene. The assumption that the Miocene marine transgression deeply eroded a karstified Cretaceous substrate on the Latium-Abruzzi platform is not supported because this surface appears in the field as a perfectly flat, bioeroded paraconformable surface. In this work, a marine origin is proposed for this unconformity. From late Paleocene to early Miocene, the Latium-Abruzzi carbonate platform was a shaved isolated platform exposed to wave action in the middle of the proto-Mediterranean area. Bioclastic sediment accumulated during transgressive and sea-level highstand phases, whereas in the following falling and lowstand stages, sediment was eroded as the seafloor came into the zone of wave abrasion. The sediment eroded from the platform was shed into the basin where it produced coarse bioclastic intercalations in the hemipelagites of the Scaglia Formation. At the end of the Oligocene, when the adjacent basin was filled, a small ramp was established in the transitional zone between the platform and the basin. There, cross-bedded carbonates accumulated in middle to outer ramp environments. The inner ramp remained within the zone of wave abrasion such that sediment generated there was washed out into the middle and outer ramp environments. Finally, in the early Burdigalian, the Mediterranean progressively evolved into closed sea during the initial stages of the closure of Indo-Pacific connection. The reduction of the wave-base depth, typical of an enclosed sea, created increased accommodation space allowing sediments to accumulate and form the complete inner to outer ramp facies belts of the Miocene Latium-Abruzzi ramp. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68110
Appears in Collections: 过去全球变化的重建
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作者单位: Dipartimento di Scienze della Terra, La Sapienza Università di Roma, P. Aldo Moro 5, I-00185 Roma, Italy
Recommended Citation:
Brandano M.. Unravelling the origin of a Paleogene unconformity in the Latium-Abruzzi carbonate succession: A shaved platform[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01