Project Details
Projekt
The Bengal Fan stratigraphy as a function of tectonic and climate - Correlation of IODP Expedition 354 results and available seismic data from the Bay of Bengal
Applicant
Dr. Tilmann Schwenk
Subject Area
Palaeontology
Geophysics
Geophysics
Term
from 2014 to 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 260964306
The Bengal Fan, which covers the entire Bay of Bengal, is the most complete recorder for the erosional history of the Himalayans. Consequently the sedimentation on the fan is controlled by the growth of the Himalaya/Tibetan system, the past evolution of the regional climate and their interactions. Therefore IODP Expedition 354 (Bengal Fan) is dedicated to study (1) the early stage of Himalayan erosion generated by the development of the Himalaya and Tibet as topographic features and (2) the Neogene history of the Asian monsoon and its impact on sediment supply and flux. The expedition was carried out in February/March 2015, co-chief scientists were C. France-Lanord and the V. Spiess. During Expedition 354 seven sites were drilled on a East-West transect at 8°N. This drilling strategy also allows determining the lateral depocenter migration typically for submarine fans, and utilizing this result during interpretation of drilling results.In the frame of this renewal proposal it is proposed to correlate results from IODP Expedition 354 and the available seismic data net from two pre-site surveys (RV Sonne cruises SO125 and SO188) in the Bay of Bengal to establish a new stratigraphy for the Bengal Fan with respect to the regional tectonic and climatic evolution. The existing stratigraphy bases a) on poor age constraints from the just spot-cored DSDP Site 218 and b) only on seismic data gathered during Cruise SO125 around 8°N. Including all available data from Cruise SO188 will extend the stratigraphy to 11°N. New dating of stratigraphic features will give new, significant insights into the build-up of the fan as a function of the histories of the Himalaya/Tibetan system and the Asian monsoon. Finally this project shall improve the general understanding of processes controlling soure-2-sink systems.In the running project phase all available seismic data were (re)-processed. A seismo-stratigraphic analysis is already ongoing and shall be continued with respect to the drilled dated hemipelagic layer to finally establish a robust regional stratigraphy. Objectives of the following interpretation will be the exact determination of the onset of channel-levee systems on the Bengal Fan, the identification of succession and average lifetimes of individual channel-levee systems for dated time slices, and the study of variations of fan architecture from north to south within these different time slices. All these results will be utilized in the budgeting of sediment fluxes, and are of significant relevance for the IODP Exp. 354 community, since results from single drill holes have to be assessed in the light of this lateral highly-dynamic system
DFG Programme
Infrastructure Priority Programmes
International Connection
France
Co-Investigator
Professor Dr. Volkhard Spieß
Cooperation Partners
Professor Dr. Christian France-Lanord; Dr. Hendrik Lantzsch
