Epicontinental seas as efficient carbon sinks: proto-Paratethys & West Siberian seas during the PETM

Kaya, Mustafa Yücel
Dupont‐Nivet, G
Frieling, Joost
Fioroni, C
Rohrmann, A
Altıner, Sevinç
Vardar, Ezgi
Plesse, Birgit
Mamtimin, Mehmut
Zhaojie, Guo
Removal of carbon on geological timescales is generally assumed to be governed by the relative strength of silicate weathering and organic carbon burial. For past transient warming phases organic carbon burial has been considered as a relevant negative feedback, but it remains uncertain how this compares to present-day anthropogenic emissions. The ocean is very effective at organic carbon remineralization and, only certain regions bury significant amounts of organic carbon. Organic carbon burial hotspots include shallow water regions along active continental margins and permanently oxygen-deficient zones. Shallow inland seas covering continents bear depositional settings with broad low-energy facies and delivery of low-reactivity, fossil (ancient) and terrestrial (both contemporary and aged, i.e., soil) organic carbon and lithogenic particles when they are associated with an active margin. These epicontinental seas might be hydrographically and geographically restricted resulting in oxygen-depleted environments. As such, epicontinental seas might serve as significant carbon sinks for all types of organic carbon components (i.e. marine, fossil, contemporary and aged terrestrial) with a high organic carbon preservation efficiency. However, oxygen deficient environments associated with epicontinental seas are currently rare and, as a consequence, organic carbon burial may be overestimated in importance as a negative feedback to anthropogenic emissions compared to the past. As part of the ERC “MAGIC” project, we study the mechanics, relative contribution and preservation efficiency of ancient epicontinental seas as carbon sinks, using organic rich deposits dated to the Paleocene – Eocene Thermal Maximum (PETM) from the proto-Paratethys and West Siberian seas. We then calculate and compare the amount of organic carbon sequestered in these basins, relative to modeled estimates of global organic carbon burial. Our data corroborates the view that the sequestration of organic carbon arises due to enhanced recycling of phosphorus from sediments under anoxic conditions and coupled increase in biological productivity. We estimate ca. 1380 Gt C burial, plausibly more than half of the estimated global total excess burial across the PETM is focused in the proto-Paratethys and West Siberian seas. This supports the hypothesis that alongside the organic carbon burial on other continental margins, the proto-Paratethys and West Siberian basins acted as significant carbon sinks, leading to the termination of the PETM. An important implication of this is that, for the present-day and other periods in the geological past with small epicontinental seas, the effectiveness of this negative carbon cycle feedback is likely greatly diminished.
EGU General Assembly 2020


Atmospheric global dust cycle and iron inputs to the ocean
Mahowald, NM; Baker, AR; Bergametti, G; Brooks, N; Duce, RA; Jickells, TD; Kubilay, N; Prospero, JM; Tegen, I (American Geophysical Union (AGU), 2005-12-30)
Since iron is an important micronutrient, deposition of iron in mineral aerosols can impact the carbon cycle and atmospheric CO2. This paper reviews our current understanding of the global dust cycle and identifies future research needs. The global distribution of desert dust is estimated from a combination of observations of dust from in situ concentration, optical depth, and deposition data; observations from satellite; and global atmospheric models. The anthropogenically influenced portion of atmospheric...
Redox Processes in Suboxic Worlds The Highly Different Benthic Geochemistry of Fe S Mn Across the Chemoclines of Baltic and Black Sea
Yücel, Mustafa; Dale, Andrew; Slomp, Caroline; Arkin, Sinan (null; 2016-07-01)
Suboxic waters and sediments are complex hotspots of nutrient recycling, metal mobilization and sequestration of organic carbon. Moreover, modern suboxic/anoxic basins are analogs of the ancient global ocean that presumably had a pelagic redox gradient. In this context, comparative analyses of redox processes in geographically distinct basins could provide new insights on the drivers of anoxic ocean processes. Here we present high-r...
Geographic patterns of elemental deposition in the Aegean region of Turkey indicated by the lichen, Xanthoria parietina (L.) Th. Fr.
Yenisoy-Karakas, S; Tuncel, Süleyman Gürdal (2004-08-15)
Lichen samples from different parts of the world have been known to accumulate elements to a greater degree than higher plants, if they are exposed to these elements from the atmosphere or from water and sediments. It has been hypothesized that lichens can be used to monitor air pollution around point and area emission sources. Local variation (variation in substrate, age and morphology of lichen samples) of element concentrations would not be large enough to affect the concentration patterns in large areas...
Ecogeochemical fate of coarse organic particles in sediments of the Rhone River prodelta
CHARLES, Francois; COSTON-GUARİNİ, Jennifer; LANTOİNE, Francois; Guarini, Jean-Marc; Yücel, Mustafa (2014-03-20)
Coarse particulate organic matter (CPOM) represents a small portion of the inner shelf sediments but occurs across all river outlets. To consider the ecogeochemical fate of CPOM in such an environment, we examined both the infauna community and secondary evidence of geochemical reactions preserved in the surface sediments of the Rhone prodelta. ICP-AES, scanning electron microscopy and energy dispersive X-ray spectrometry of the CPOM showed that the fate of organic matter in this environment is driven by su...
Sayıt, Kaan (2013-06-01)
The Earth's mantle is known to be heterogeneous at different scales, which has been generally linked to the presence of diverse mantle reservoirs, some of which are believed to have remained isolated for long periods of time. When oceanic island basalts (OIBs) are subdivided into five distinct end-member groups on the basis of Sr-Nd-Pb isotope systematics, which include DM, EM1, EM2, HIMU and C, trace element systematics do not appear to be effective discriminators as isotopes, though an end-member signatur...
Citation Formats
M. Y. Kaya et al., “Epicontinental seas as efficient carbon sinks: proto-Paratethys & West Siberian seas during the PETM,” presented at the EGU General Assembly 2020, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57086.