Del Siro, Chantal and Czerski, Dorota and Peduzzi, Sandro and Storelli, Nicola and Scapozza, Cristian (2023) Geomorphology and stratigraphic record of the Murinascia Grande delta in Lago Ritóm since the deglaciation (Piora Valley, Southern Swiss Alps). In: XXI INQUA Congress 2023, 14-20.07.2023, Rome, Italy.
Full text not available from this repository.Abstract
The Lago Ritóm is located in the Piora Valley at 1849 m a.s.l., on the southern side of the Swiss Alps, in a natural basin carved by ice during the Last Glacial Maximum. The natural dam of Lago Ritóm consists of a rock sill, whereas the artificial dam was built in 1917 for the construction of a hydroelectric power plant. The construction of the dam led to an increase in the water level in the basin from 1828 m a.s.l. to a maximum elevation of 1850 m a.s.l., resulting in the flooding of the delta of the Murinascia Grande, the main lateral tributary located northeast of the basin. However, since the summer season of 2020, the water level decreased below 1827 m a.s.l. due to the maintenance of the hydroelectric dam, allowing the emersion of the Murinascia Grande delta. The subsequent fluvial erosion caused the exposure of the fluvio-deltaic sequence. Approximately ten meters of alluvial deposits with layers of silts and organic muds, sands from finer to coarser, and gravels were observed and described on the field. The organic sediments together with pieces of wood were sampled for radiocarbon dating at different levels in the stratigraphy. This approach was combined with a detailed 3D photogrammetric model of the delta obtained through a drone survey. Based on previous studies on palynological records, the development of the vegetation in the area was attested during the Lower Holocene at around 9 ka b2k. As a result, the radiocarbon dating on the delta deposits will probably provide a chronology covering a period included between the Middle to the Upper Holocene (8.24–0 ka b2k). The dating, together with the estimation of the volumes and thicknesses of the deposits from the digital terrain model, will allow tracing the variation of the sedimentation rate on the delta in time. The results will provide information about the timing of development and the evolution of an Alpine delta during the Holocene, providing evidence on the response of the hydrosedimentary regime to the climate oscillations and therefore on the palaeoclimatic and palaeoenvironmental conditions on a regional scale.
| Item Type: | Article in conference proceedings or Presentation at a conference (Poster) |
|---|---|
| Subjects: | Physical sciences > Geology > Earth science > Quaternary studies Physical sciences > Science of aquatic & terrestrial environments > Climatology > Climate & climate change Physical sciences > Physical geographical sciences > Physical geography > Geomorphology |
| Department/unit: | Dipartimento ambiente costruzioni e design > Istituto scienze della Terra |
| Depositing User: | Chantal Del Siro |
| Date Deposited: | 24 Jul 2023 04:33 |
| Last Modified: | 24 Jul 2023 04:34 |
| URI: | http://repository.supsi.ch/id/eprint/14462 |
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