IODP Expedition 354; a Bengal Fan record of Himalayan erosion, weathering and organic carbon burial during the Neogene

Author(s): France-Lanord, C.; Spiess, V.; Klaus, A.; Galy, Albert; Galy, Valier
Author Affiliation(s): Primary:
Université Lorraine, Centre de Recherches Pétrographiques et Géochimiques, Vandoeuvre les Nancy, France
Other:
University of Bremen, Germany
Texas A&M University College Station, United States
Woods Hole Oceanographic Institution, United States
Volume Title: AGU 2015 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2015; American Geophysical Union 2015 fall meeting, San Francisco, CA, Dec. 14-18, 2015. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The development of the Himalayan orogen induced a major change in continental distribution, topography and climate that impacted the global biogeochemical cycles. The development of the highest mountain range coupled to the intense monsoonal precipitation regime generated an intense erosional flux that enhanced both organic carbon burial and silicate weathering. The largest part of the sediment flux was exported to the Bengal Fan, accumulating a long-term archive of this erosion. These sediments record the nature of eroded formations in the Himalaya and allow the documentation of weathering as well as organic carbon fluxes. In February-March 2015, IODP Expedition 354 drilled an E-W transect in the middle fan at 8°N to investigate interactions between the growth of the Himalaya, the development of the Indian monsoon, and processes affecting the carbon cycle. This expedition obtained a comprehensive record of turbiditic deposition since the Late Oligocene. Shipboard results reveal that the chemical and mineralogical compositions of turbiditic sediments cored across the transect are relatively stable throughout the Neogene. They reveal a weak regime of chemical weathering with no significant variation through time. This differs from the distal fan record (Leg 116) where from ≈7 to 1 Ma, weathered and smectite rich sediments dominated. This difference implies that the distal fan record is not related to a direct evolution of the erosion regime but rather is controlled by a change in sediment transport within the fan. Shipboard estimates of organic carbon loading and behavior resemble observations made in the modern Ganga-Brahmaputra river sediments, suggesting efficient terrestrial organic carbon burial in the Bengal Fan. Preliminary observations support the idea that Himalayan erosion has consumed atmospheric CO2 through the burial of organic carbon, more than by silicate weathering. http://dx.doi.org/10.1038/nature06273
Year of Publication: 2015
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Asia; Bengal Fan; Carbon; Carbon cycle; Cenozoic; Expedition 354; Geochemical cycle; Himalayas; Indian Ocean; Integrated Ocean Drilling Program; Marine sediments; Neogene; Sediments; Tertiary
Record ID: 2016075448
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union, Washington, DC, United States

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