Inferring denudation variations from the sediment record; an example of the last glacial cycle record of the Golo Basin and watershed, East Corsica, western Mediterranean sea

Abstract

International audienceGeophysical data and sampling of the Golo Basin (East Corsica margin) provide the opportunity to study mass balance in a single drainage system over the last 130 kyr, by comparing deposited sediments in the sink and the maximum eroded volume in the source using total denudation proxies. Evaluation of the solid sediments deposited offshore and careful integration of uncertainties from the age model and physical properties allow us to constrain three periods of sedimentation during the last climatic cycle. The peak of sedimentation initiated during Marine Isotopic Stage (MIS) 3 (ca. 45 ka) and lasted until late in MIS 2 (ca. 18 ka). This correlates with Mediterranean Sea palaeoclimatic records and the glaciation in high altitude Corsica. The yield of solid sediment into the Golo Basin drops in the observed present day Mediterranean basins (gauging stations), whereas the palaeo-denudation estimate derived from the sediments over the last glacial period is one to ten times higher than that predicted using cosmogenic or thermochronometer estimates of exhumation. The catchment-wide denudation rate calculated from deposited solid sediment ranges from 47 to 219 mm kyr−1, which is higher than the estimate from palaeosurface ablation in the proximal part of the source (9-140 mm kyr−1) and lower than the distal, narrow, incised channel of the Golo River (160-475 mm kyr−1). This mismatch raises questions about the investigation of denudation at millennial-time scale (kyr) and at higher integrating times (Myr) as a reliable tool for determining the effect of climate change on mountain building and on sedimentary basin models

Levantine intermediate water hydrodynamic and bottom water ventilation in the northern Tyrrhenian Sea over the past 56,000 years: New insights from benthic foraminifera and ostracods

“…1). The latter drains several small, steep mountain rivers (the Golo River being the longest with a length of 90 km) that transport mainly coarse-grained material toward the deep part of the basin (Calv es et al, 2012).…”

Non-linear response of the Golo River system, Corsica, France, to Late Quaternary climatic and sea level variations

“…Oxygen-isotopes, sedimentary, and pollen records indicate high amplitude and high frequency fluctuations in the Mediterranean region during the Quaternary (Peyron et al, 1998;Ramrath et al, 1999;Cacho et al, 2002;Tzedakis, 2005;Brauer et al, 2007;Calv es et al, 2012;Toucanne et al, 2012). The correlation between the oxygen isotopes Mediterranean record, the ice core record in Greenland and the sedimentary record in the Atlantic and Northern Europe (Dansgaard et al, 1993;GRIP, 1993;Allen et al, 1999;Kallel et al, 2000;Martrat et al, 2004;Svensson et al, 2008) implies that during the Last GlacialeInterglacial cycle, climatic changes produced a similar environmental response at a continental scale (Fig.…”

“…Climatic oscillations importantly affected denudation rates in the Golo catchment (Sømme et al, 2011;Calv es et al, 2012) with a large increase in sediment production during glacial phases. This ; Golo source to sink system (C).…”

“…References for palaeo-climatic proxies: Ngrip (GRIP, 1993); SU90-08 (Paterne et al, 1999;Kallel et al, 2000); ODP-977A (Martrat et al, 2004); T. Philippon (Tzedakis, 2005); MD99-2348 (Rabineau et al, 2005); MD01-2434 Calv es et al, 2012); KET89-03 (Paterne et al, 1999;Kallel et al, 2000); Monticchio (Ramrath et al, 1999;Allen et al, 1999); Lac de Creno (Reille et al, 1997(Reille et al, , 1999 behavior, characteristic for several catchments across Europe (Collier et al, 2000;Hinderer, 2001;Bogaart et al, 2003;Busschers et al, 2007), was the result of sparse vegetation cover, permafrost processes and glacial erosion (Conchon, 1978, Kuhlemann et al, 2005de Winter et al, 2012). Chemical weathering was high during interglacial periods, as a consequence of higher temperature, precipitation, vegetation cover and the enhanced development of soils (Calv es et al, 2012). On a longer time scale, denudation rates, measured by 10 Be cosmogenic nuclides on high elevation Miocene palaeo-surfaces (0.008e0.024 mm/y) (Kuhlemann et al, 2007), are one order of magnitude lower than Quaternary fluvial incision rates (0.2e0.4 mm/y) (Fellin, 2005) and sediment yield to the Corsica Trough (Calv es et al, 2012) (0.04e0.1 mm/y).…”

“…Recent studies on the catchment and alluvial-coastal plain (Sømme et al, 2011;Skyles, 2013;Moreau et al, in prep. ), and on the shelf and submarine fans (Deptuck et al, 2008;Gervais et al, 2006aGervais et al, , 2006bSømme et al, 2011;Calv es et al, 2012) have given new insights into the architecture and evolution of the Golo River system, illustrating how major modifications in stratigraphy, sediment storage and dispersal occurred as a response to climatic and eustatic sea level changes. The cut-and-fill pattern of the Golo fluvial terraces and the stacking pattern of sedimentary unit on the shelf were interpreted by Sømme et al (2011) as the result of balance/imbalance between sediment supply and fluvial transport capacity.…”