TY - JOUR
T1 - Quaternary evolution of the Golo river alluvial plain (NE Corsica, France)
AU - Molliex, Stéphane
AU - Jouet, Gwenael
AU - Blard, Pierre Henri
AU - Moreau, Julien
AU - Demartini, Julie
AU - Storms, Joep E.A.
AU - Vella, Claude
AU - Team, Aster
PY - 2021
Y1 - 2021
N2 - The Golo River drains a steep catchment (average gradient of 30 m km−1, surface of 1214 km2) in the northeast part of Corsica Island, delivering sediments to the Ligurian Sea. In this study, we review and revise the geologic map and constrain the extent of the Golo coastal alluvial plain formations and their relative and absolute chronology. To update the surface extent of each formation, we performed a geomorphologic analysis with DEMs and satellite imagery data coupled with an extensive pedogenic and sedimentary field observations database, including a new borehole of 117,4 m depth. Additionally, we performed in-situ cosmogenic 10Be analysis from a depth-profile in the well-preserved alluvial terrace Fy2, yielding a minimum age of 70 ka for its emplacement. Our new chronology, based on cosmogenic 10Be and soil chronosequences, implies older ages than those previously obtained with luminescence methods. Soil mixing by bioturbation is proposed as a possibility to explain differences between luminescence and 10Be ages. In this scenario, 10Be dates the original deposition of the alluvial terrace, while luminescence dates a later soil development. We highlighted at least five outcropping alluvial terraces in the Golo coastal plain, which are controlled by sea-level fluctuations and were most likely deposited during past sea-level highstands (close to present-day sea-level). Moreover, we identified from a borehole more than 117 m of coarse fluvial sediments in the plain, that do not outcrop at the surface. New cosmogenic 26Al/10Be burial ages suggest that this sedimentary unit results from a thick accumulation of fluvial material filling a zone significantly affected by subsidence, probably accommodated by a normal fault during the Early Quaternary.
AB - The Golo River drains a steep catchment (average gradient of 30 m km−1, surface of 1214 km2) in the northeast part of Corsica Island, delivering sediments to the Ligurian Sea. In this study, we review and revise the geologic map and constrain the extent of the Golo coastal alluvial plain formations and their relative and absolute chronology. To update the surface extent of each formation, we performed a geomorphologic analysis with DEMs and satellite imagery data coupled with an extensive pedogenic and sedimentary field observations database, including a new borehole of 117,4 m depth. Additionally, we performed in-situ cosmogenic 10Be analysis from a depth-profile in the well-preserved alluvial terrace Fy2, yielding a minimum age of 70 ka for its emplacement. Our new chronology, based on cosmogenic 10Be and soil chronosequences, implies older ages than those previously obtained with luminescence methods. Soil mixing by bioturbation is proposed as a possibility to explain differences between luminescence and 10Be ages. In this scenario, 10Be dates the original deposition of the alluvial terrace, while luminescence dates a later soil development. We highlighted at least five outcropping alluvial terraces in the Golo coastal plain, which are controlled by sea-level fluctuations and were most likely deposited during past sea-level highstands (close to present-day sea-level). Moreover, we identified from a borehole more than 117 m of coarse fluvial sediments in the plain, that do not outcrop at the surface. New cosmogenic 26Al/10Be burial ages suggest that this sedimentary unit results from a thick accumulation of fluvial material filling a zone significantly affected by subsidence, probably accommodated by a normal fault during the Early Quaternary.
KW - Be depth-Profile
KW - Alluvial plain
KW - Corsica
KW - Electric resistivity tomography
KW - Geomorphology
KW - Quaternary
KW - Soil sequence chronology
KW - Terraces
UR - http://www.scopus.com/inward/record.url?scp=85090402794&partnerID=8YFLogxK
U2 - 10.1016/j.quageo.2020.101115
DO - 10.1016/j.quageo.2020.101115
M3 - Article
AN - SCOPUS:85090402794
VL - 61
JO - Quaternary Geochronology
JF - Quaternary Geochronology
SN - 1871-1014
M1 - 101115
ER -