Long-period astronomically-forced terrestrial carbon sinks

Sequestration of organic matter by peat accumulation constitutes a primary sink for carbon in the global carbon cycle. The processes that control the formation and storage of peat at geological time scales are poorly understood but are of a non-solved issue of fundamental importance for understandin...

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Detalles Bibliográficos
Autores: Valero Montesa, Luis, Cabrera, Lluís, Sáez, Alberto, Garcés Crespo, Miguel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/98209
Acceso en línea:https://hdl.handle.net/2445/98209
Access Level:acceso abierto
Palabra clave:Rotació de la Terra
Magnetoestratigrafia
Paleoclimatologia
Oligocè
Cicle del carboni (Biogeoquímica)
Earth rotation
Magnetostratigraphy
Paleoclimatology
Oligocene
Carbon cycle (Biogeochemistry)
Descripción
Sumario:Sequestration of organic matter by peat accumulation constitutes a primary sink for carbon in the global carbon cycle. The processes that control the formation and storage of peat at geological time scales are poorly understood but are of a non-solved issue of fundamental importance for understanding the global climate system. We analyzed a 7million years long terrestrial record of Late Oligocene age from the As Pontes Basin in Northern Spain, which demonstrates that minima in the 405-kyr and 2.4-Myr eccentricity cycles play a key role in peat formation. Such nodes exhibit reduced precession amplitudes, thus avoiding extremes in seasons and seasonal contrast for a prolonged period of time. In the As Pontes Basin, this orbital configuration is associated with a decrease in siliciclastic sedimentation and enhanced peat formation. Feedbacks between equilibrium landscapes and ecosystem stability will lead to a deceleration of weathering and erosion rates in catchment areas and to minimum and stable sediment flux along the sediment routing system. Mid-latitude peat burial could contribute to disturb the carbon cycle by removing (atmospheric) carbon at times of minimum eccentricity.